Hematopathology Case Study: A 67 Year Old Female with a Sore Throat

History 

A 67 year old female presents with a two-month history of sore throat. She endorses dysphagia and left-sided otalgia but denies voice changes, shortness of breath, hemoptysis, weight loss, fever or night sweats. She has smoked 1 pack/day for 41 years and occasionally drinks alcohol. Her past medical history is notable for systemic lupus erythematosus for which she takes Plaquenil.

Physical examination slightly elevated systolic blood pressure. She is afebrile. Pertinent neck exam findings include mild tonsillar asymmetry (left slightly larger than right), and a firm mass at left base of tongue, and a 3 cm lymph node in the neck (left level III). A biopsy sample was taken from the tongue mass. 

Biopsy

EBV-1

H&E stained sections reveal sheets of large lymphocytes. The lymphoid cells are medium to large in size with irregular nuclear contours and prominent nuclei. Areas of necrosis are prominent. No specific areas of epithelial ulceration are noted. Immunophenotypic characterization of the larger cells reveals positivity for CD20, CD30, CD79a, PAX5, MUM1, Epstein Barr virus encoded RNA (EBER) and a variable Ki-67 proliferation index, which is up to 60-70% in the larger cells, but around 20-30% overall. Only rare cells are positive for BCL-2 and BCL-6. The lymphoma cells are negative for keratin AE1/AE3, CD10, CD4, CD8, CD21, CD23, CD7, CD5, Cyclin D1, CD68, CD56, and CD43. The background T cells express CD5 and CD7 and are a mixture of CD4 and CD8 with CD4 predominance.

We considered the diagnosis of EBV-positive mucocutaneous ulcer (a more indolent entity); however, the lack of history of an ulcer/ulceration and the presence of a mass-lesion (with additional adenopathy) does not support this diagnosis.

The findings are most consistent with EBV-positive DLBCL, NOS (WHO 2017), previously known as EBV positive DLBCL of the elderly (WHO 2008). 

Discussion 

Epstein Barr Virus, a member of the Herpesviridae family is mostly known for causing Infectious Mononucleosis. However, the ubiquitous virus which is present in about 90% of adults but often asymptomatic1, has a predilection for epithelial cells including B-cells.2 Incorporation of the viral genome and viral takeover of the cells proliferative machinery underlies the pathogenesis of any EBV-related disease/malignancy. It has been associated with a gastric carcinoma, fulminant hepatitis, undifferentiated nasopharyngeal carcinoma, and B cell, T cell and NK cell lymphomas3, including EBV+ diffuse large B-cell lymphoma, not otherwise specified (DLBCL-NOS).

EBV-positive diffuse large B-cell lymphoma, not otherwise specified (EBV+ DLBCL-NOS) was formerly known as EBV-positive diffuse large B-cell lymphoma (DLBCL) of the elderly. The WHO classification substituted “not otherwise specified” in place of “for the elderly” to reflect two things: 1) EBV is associated with other specific neoplastic Large B-Cell diseases such as lymphomatoid granulomatosis, and 2) EBV+DLBCL can affect younger individuals as well as the elderly. 2

EBV+DLBCL-NOS patients may occur in nodal or extranodal sites, with up to 40% presenting with extranodal sites at least in the early stages. Patients may be asymptomatic with or without B symptoms but usually, patients present with rapidly enlarging tumors at single or multinodal sites, as well as at extranodal sites. 4

The patient’s presentation with sore throat and the finding of neck mass with EBV-positive large B-cells associated with ulcer-like necrosis raises a differential diagnosis that ranges from reactive to malignant. Table 1 shows a comparison between three differential diagnoses: EBV+DLBCL-NOS; EBV-positive mucocutaneous ulcer; and infectious mononucleosis.

EVB-t1
Table 1. Comparison of 3 EBV-positive differentials in the head and neck

Unfortunately, there is currently no uniformly agreed standard of treatment for EBV+DLBCL which has a worse prognosis than EBV negative DLBCL.2 The standard treatment for DLBCL (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone- R-CHOP) is used but it responds poorly to treatment, with a median survival of 2 years.

Therefore, early detection by clinical suspicion and testing all DLBCL patients for EBV is very important.2 

 References

  1. Tsuchiya S. Diagnosis of Epstein–Barr virus-associated diseases. Critical Reviews in Oncology and Hematology. 2002;44(3):227-238. https://www.sciencedirect.com/science/article/pii/S1040842802001142. doi: 10.1016/S1040-8428(02)00114-2.
  2. Murthy SL, Hitchcock MA, Endicott-Yazdani T, Watson JT, Krause JR. Epstein-barr virus–positive diffuse large B-cell lymphoma. Proceedings (Baylor University.Medical Center). 2017;30(4):443-444. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595389/.
  3. Okano, Motohiko, MD, PhD|Gross, Thomas G., MD, PhD. Acute or chronic life-threatening diseases associated with epstein-barr virus infection. American Journal of the Medical Sciences, The. 2012;343(6):483-489. https://www.clinicalkey.es/playcontent/1-s2.0-S0002962915309435. doi: 10.1097/MAJ.0b013e318236e02d.
  4. Swerdlow S, Campo E, Harris NL, Jaffe ES, Pileri SA, Stein H, Thiele J, Arber D, Hasserjian R, Le Beau M. WHO classification of tumours of haematopoietic and lymphoid tissues. 2017.
  5. Dunmire SK, Hogquist KA, Balfour HH. Infectious Mononucleosis. Current topics in microbiology and immunology. 2015;390:211-240. doi:10.1007/978-3-319-22822-8_9.

 

Adesola picture-small

-Adesola Akinyemi, M.D., MPH, recently earned his MPH-Health Policy and Management from New York Medical College. He plans on pursuing residency training in pathology. His interests include cytopathology, neuropathology, and health outcomes improvement through systems thinking and design.

Mirza-small

-Kamran M. Mirza, MD PhD is an Assistant Professor of Pathology and Medical Director of Molecular Pathology at Loyola University Medical Center. He was a top 5 honoree in ASCP’s Forty Under 40 2017. Follow Dr. Mirza on twitter @kmirza.

Hematopathology Case Study: Two Cases with Surprising Hematopoetic Elements

Case 1 History

Sixty-one year old man with new diagnosis of Bud-Chiari syndrome and extensive peripheral, splenic and hepatic venous thrombosis with increasing fatigue, abdominal discomfort and abnormal liver function tests. A liver biopsy was performed and a hypercoagulability work-up, including JAK2 mutation analysis was initiated.

2-cases-liver2x
Liver core biopsy 2X
2-cases-liver10x
Liver core biopsy 10X

Diagnosis

The liver biopsy showed extensive hemorrhage, hepatocellular necrosis and collapse with mild portal and lobular mixed inflammation. Occasional megakaryocytes and nucleated red blood cell precursors were noted. The case was sent to hematopathology for further review.

2-cases-liver40x
Liver core biopsy 40X
2-cases-liver40x2
Liver core biopsy 40X
2-cases-jak2analysis
JAK2 Mutations Analysis

Hematopathology Diagnosis

Sections show liver parenchyma with changes of the patient’s known history of venous outflow obstruction, as well as extramedullary hematopoiesis, including scattered megakaryocytes (arrows) and erythroid precursors (circle). In the setting of a positive JAK2 V617F mutation, this constellation of findings is consistent with a myeloproliferative neoplasm.

Case 2 History

Fifty-nine year old man with a history of hypertension and alcohol abuse with posterior mediastinal lymphadenopathy. Recent bone marrow biopsy showed mildly hypercellular bone marrow with megakaryocytic and myeloid hyperplasia, and increased stromal reticulin with concern for primary myelofibrosis. A lymph node biopsy was performed.

2-cases-lymph10x.jpg
Lymph node biopsy 10X
2-cases-lymph40x
Lymph node biopsy 40X
2-cases-myelo.jpg
Myeloperoxidase
2-cases-CD71
CD71
2-cases-CD61
CD61
2-cases-CD34
CD34
2-cases-CD3
CD3
2-cases-CD20
CD20

Diagnosis

The lymph node biopsy shows fragments composed of adipocytes and maturing trilineage hematopoiesis. Multiple small to medium sized lymphoid aggregates are also seen, composed of small and mature appearing lymphocytes. The lymphocytes are a mixture of CD3 positive T cells and CD20 positive B cells with focal B cell predominance. Myeloperoxidase highlights myeloid precursors, which comprise 70-80% of the cellularity. CD71 highlights erythroid precursors, which comprise 20-30% of the cellularity. CD61 highlights megakaryocytes. CD34 highlights vessels and only rare CD34-positive cells are seen. Taken together, the findings are consistent with extramedullary hematopoiesis.

Discussion

Extramedullary hematopoiesis (EMH) is defined as hematopoiesis that occurs outside of the bone marrow. It can occur in both normal and pathologic states and has been seen in several hematologic disorders including chronic myeloproliferative neoplasms. Myeloproliferative neoplasms (MPN) are a group of clonal hematopoetic stem cell disorders that include polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF).1 JAK2V617F mutation is the most frequent mutation associated with MPNs, found in roughly 96% of patients with PV and 65% of patients with ET and PMF. This mutation leads to constitutive activation of the JAK/STAT pathway and is a driver of myeloproliferation.2  The patient in case 1 was found to have a JAK2 mutation during the work-up for hypercoagulability. This suggests that he may have an underlying MPN, however JAK2 mutations have been found in patients with venous thrombosis, but without overt evidence of MPNs.3 The patient in case 2 had a bone marrow biopsy with features concerning for primary myelofibrosis. In PMF, there is generally a proliferation of myeloid cells in addition to marrow fibrosis. Increasing fibrosis can eventually result in pancytopenia as the fibrosis takes over the marrow space in addition to altering the bone marrow environment so that it is unable to support normal hematopoiesis. Ultimately, this can lead to extramedullary hematopoesis. EMH most commonly occurs in the spleen and liver, but has been described in many other sites including the mediastinum and lymph nodes. In addition to being a driver of proliferation, it is thought that JAK2 mutations make hematopoetic stem and progenitor cells more sensitive to growth factors and can cause the cells to mobilize to the liver and spleen.4  Patients with EMH can have symptoms related to the site of involvement. Depending on the extent of involvement and location, EMH may require treatment with low dose radiation. While EMH is a rare finding, it should prompt an investigation for an underlying MPN.

References

  1. Imai K, Aoi T, Kitai H,et al. A case of perirenal extramedullary hematopoiesis in a patient with primary myelofibrosis. CEN Case Reports. 2017;6(2):194-199. doi:10.1007/s13730-017-0274-1.
  2. Kim CH. Homeostatic and pathogenic extramedullary hematopoiesis. Journal of blood medicine. 2010;1:13-19.3https://www.ncbi.nlm.nih.gov/pubmed/17263783.
  3. De Stefano, V, Fiorini, A, Rossi, E, et al. Incidence of JAK2 V617F mutation among patients with splanchnic or cerebral venous thrombosis and without overt chronic myeloproliferative disorders. Journal of Thrombosis and Haemostasis. 2007;5(4):708-14. https://www.ncbi.nlm.nih.gov/pubmed/17263783.
  4. Passamonti F, Maffioli M, Caramazza D, et al. Myeloproliferative neoplasms: From JAK2 mutations discovery to JAK2 inhibitor therapies. Oncotarget. 2011;2(6):485-490.

Marcus, Chelsea_099-Edit

Chelsea Marcus, MD is a third year resident in anatomic and clinical pathology at Beth Israel Deaconess Medical Center in Boston, MA and will be starting her fellowship in Hematopathology at BIDMC in July. She has a particular interest in High-grade B-Cell lymphomas and the genetic alterations of these lymphomas.

Hematopathology Case Study: A 16 Year Old Male with Fatigue, Fevers, and Weight Loss

Case History

16 year old male with a history of chronic pilonidal cyst presented with fatigue, fevers and weight loss. He was febrile and noted to have cervical and inguinal adenopathy. Labs were significant for a white count of 77,000 with 85% peripheral blasts, anemia and thrombocytopenia.

MPAL1
Bone marrow aspirate
MPAL2
Bone marrow core biopsy
MPAL3.png
Flow cytometry myeloid markers
MPAL4
Flow cytometry cytoplasmic markers
MPAL5
Flow cytometry T-cell markers

Diagnosis

The bone marrow aspirate shows cellular spicules with sheets of intermediate-to-large sized mononuclear cells with irregular nuclei, distinct nucleoli, dispersed chromatin, and scant to generous amphophilic cytoplasm, with occasional vacuoles, consistent with blasts.

The bone marrow core biopsy shows a greater than 95% cellular marrow, hypercellular for age with approximately 90% of the cellularity composed of an interstitial population of intermediate-to-large sized mononuclear cells with irregular nuclei, distinct nucleoli, dispersed chromatin, and scant to generous amphophilic cytoplasm, with occasional vacuoles, consistent with blasts.

Flow cytometry shows leukemic cells that express immaturity markers (TdT, CD34, CD117, HLA-DR), T cell lineage markers (CD2, CD7 cCD3), and multiple myeloid markers (CD13, CD117, and variable CD15 and CD11b as well as MPO in a small subset).

Bone marrow core biopsy staining (not shown) had similar findings with blasts showing dim-to-strong positivity for myeloperoxidase, lysozyme, CD34 and CD117, as well as strong positivity for TdT. CD7 was weakly positivity, as well as CD3. CD4 and CD5 were negative.

MPAL6
Genetics diagnostics
MPAL7
NGS panel

With the expression of MPO by flow cytometric analysis and immunohistochemistry, a final diagnosis of acute leukemia with myeloid and T lymphoid phenotypic features, most consistent with T/Myeloid Mixed Phenotype Acute Leukemia (MPAL) was rendered. 

Discussion

Most acute leukemias are definitively assigned to either myeloid, T or B lymphoid lineages. However, approximately 2-5% of patients diagnosed with acute leukemia display an ambiguous lineage after immunophenotyping. A portion of these cases are classified under the category of mixed phenotype acute leukemia (MPAL) by the current WHO nomenclature.1

In a study of 117 MPAL patients by Yan et al, 55% of the cases had combined B/Myeloid, while 33% had T/Myeloid, and 12% had B/T/Myeloid. CD34 was strongly positive in 82% of cases, which reinforces the idea that the cell of origin is a multi-potent stem cell capable of differentiating into both myeloid and lymphoid progenitors. Cytogenetic analysis revealed no chromosomal abnormality in 36% of the patients with MPAL, while 64% had complex karyotypes (>3 aberrations). Translocation (9;22) was the most common abnormality, found in 15% of patients. Monosomy 7, a common finding in myelodysplastic syndromes as well, was found in 7.6% of patients. Mutational analysis revealed IKZF1 deletions in 13% of patients, ASXL1 in 6.5% of patients and a variety of other mutations including ETV6, NOTCH1 and TET2.2

In 2016, Eckstein and colleagues demonstrated epigenetic regulatory genes such as DNMT3A, IDH2, TET3 and EZH2 are the most commonly mutated in MPAL. RAS mutations including NRAS and KRAS and tumor suppressors, such as TP53 and WT1, were frequently identified as well.3

Interestingly enough, the genetic features of MPAL often overlap with early T-cell precursor acute lymphoblastic leukemia (ETP-ALL). ETP-ALL is a high-risk subgroup, representing 10% of adult T-lineage acute lymphoblastic leukemia. It is defined by a characteristic immunophenotype (CD1a/CD8 negative with weak CD5) and distinct gene expression associated with early arrest in T-cell development. This subgroup, called the LYL1 group, expresses the early hematopoietic marker CD34 as well as myeloid antigens (CD13 or CD33), but lacks expression of both CD4 and CD8. These leukemias are associated with a poor prognosis, with a 10- year overall survival of 19% compared to 84% for all other T-ALLs.4

Zhang et al in 2012 performed whole genome sequencing on ETP-ALL cases and found a high frequency of mutations in factors mediating cytokine receptor, tyrosine kinase and RAS signaling. It also showed inactivating mutations in genes encoding transcription factors (GATA3, ETV6, RUNX1, IKZF1) as well as genes involved in histone modification, such as EZH2.5

Overall, the genetic features of both ETP-ALL and MPAL display an identical genomic pattern that involves multiple pathways, including tyrosine kinase signaling, cytokine receptor response, RAS pathway activation, and loss of function in tumor suppressors. These findings give credence to the hypothesis that the early T-cell precursor actually displays more of a pluripotent stem cell profile that is similar to myeloid neoplasms, thus confounding findings found during molecular profiling. With this paradigm in mind, molecular diagnostics cannot differentiate between ETP-ALL and in this case, MPAL.

 

References

  1. Swerdlow, Steven H. WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Revised 4th ed., International Agency for Research on Cancer, 2017.
  2. Yan et al. Clinical, immunophenotypic, cytogenetic, and molecular genetic features in 117 patients with mixed-phenotype acute leukemia defined by WHO-2008 classification. 2012 November;97(11):1708-12.
  3. Eckstein OS et al. Mixed Phenotype Acute Leukemia (MPAL) Exhibits Frequent Mutations in DNMT3A and Activated Signaling Genes. Exp Hematol. 2016 August; 44(8):740-744.
  4. Ferrando AA et al.  Gene expression signatures define novel oncogenic pathways in T cell acute lymphoblastic leukemia. Cancer Cell. 2002. 1:75–87.
  5. Zhang J et al. The genetic basis of early T-cell precursor acute lymphoblastic leukemia. Nature. 2012 Jan 11;481(7380):157-63.

 

Marcus, Chelsea_099-Edit

Chelsea Marcus, MD is a third year resident in anatomic and clinical pathology at Beth Israel Deaconess Medical Center in Boston, MA and will be starting her fellowship in Hematopathology at BIDMC in July. She has a particular interest in High-grade B-Cell lymphomas and the genetic alterations of these lymphomas.

Hematopathology Case Study: A 68 Year Old Man with Epidural Mass

Case History

A 68 year old man with no significant past medical history presented with 3 weeks of upper back pain and bilateral leg weakness. He denied numbness, tingling, leg pain or urinary or fecal incontinence. MRI showed severe cord compression at the upper thoracic spine with a T2-T5 epidural mass. Due to the patient’s decline, an urgent decompression was scheduled and the patient underwent T2-T5 thoracic laminectamies with resection of extramedullary epidural tumor.

MRI-t2
MRI T2 SAG T-Spine
frozhe2x
Frozen Section H&E, 2x 
frozhe20x
Frozen Section H&E, 20x

Imaging

Frozen Section Diagnosis

“Round blue cell tumor.  Await permanents for final diagnosis.”

Differential Diagnosis

Small round blue cell tumor is a term generally used for a group of neoplasms characterized by small, round, basophilic, relatively undifferentiated cells on H & E staining. The differential diagnosis is wide, but includes Ewing’s sarcoma/peripheral neuroectodermal tumor, mesenchymal chondrosarcoma, small cell osteosarcoma, desmoplastic small round cell tumor and Non-Hodgkin Lymphoma. 1

 he2x

H&E, 2x

he4x
CD20, 4x

 

cd20-4x
CD20, 4x
bcl2-4x
BCL2, 4x
cd10-4x
CD10, 4x
cd21-4x
CD21, 4x
ki-67
Ki-67, 4x
IGH
IGH/BCL2 double fusion FISH probe. White arrows: IGH/BCL2 fusion

Diagnosis

Sections show fragments of fibrous tissue and focal bone with extensive crush artifact. There is an abnormal lymphoid infiltrate with areas showing a vaguely nodular architecture. The lymphocytes are small to medium in size with irregular cleaved nuclei, inconspicuous nucleoli and small amounts of cytoplasm. Scattered centroblastic cells are seen but are <15 per high power field. Between the nodules, the cells are centrocytic appearing. Rare mitotic figures are identified.

By immunohistochemistry, the neoplastic cells are immunoreactive for CD20 and BCL2. BCL2 is brighter in the vague nodular areas which are also highlighted by CD10 and BCL6. CD23 is variably positive in a large subset of cells. MUM1 is negative. CD21 highlights the enlarged and irregularly shaped follicular dendritic cell meshwork present in the areas with nodules. CD3 and CD5 highlights admixed T-cells. The proliferation index by Ki-67 is low and approximately 10%.

Cytogenetic analysis using fluorescent in-situ hybridization performed on paraffin embedded sections revealed numerous cells with an IGH/BCL double fusion probe signal pattern consistent with IGH/BCL2 gene rearrangement.

Overall, the morphologic and immunophenotyipic findings in conjunction with the cytogenetic results are in keeping with involvement by a B-cell lymphoma most consistent with a follicular lymphoma. The follicles present contain <15 centroblasts per hpf and the low proliferation fraction makes it most compatible with a low grade (WHO morphologic grade 1-2/3) follicular lymphoma.

Discussion

The differential diagnosis for an extramedullary epidural tumor is wide and can include anything from an epidural abscess to a metastasis. Although rare, lymphoma must be considered, especially when initial pathology shows “Round blue cells.”

Making the diagnosis of follicular lymphoma involves assessing the H & E slides for follicular architecture, characteristic immunostains including positivity for BCL2 within follicles and the typical t(14;18) IGH/BCL2 translocation, which occurs in 90% of cases. 2

Primary spinal epidural lymphoma (PSEL) includes extramedullary/extranodal lymphomas of the epidural space for which there are no other sites of disease at the time of diagnosis. As demonstrated in Figure 1 below, the lymphoma is seen entirely within the epidural space. 3

fig1
Figure 1. Primary spinal epidural lymphomas. Journal of Craniovertebral Junction and Spine (2011).

 

An epidural location for lymphoma is observed in 0.1-6.5% of cases. Patients tend to present in the fifth to seventh decade of life with a higher proportion of male to female cases. Presenting symptoms include weakness in the upper or lower limbs and back pain corresponding to the site of involvement of tumor. The most common tumor site is the thoracic spine (75%) followed by lumbar and cervical. Most epidural spinal tumors are B-cell lymphomas of intermediate and high grade, but low grade lymphomas have been reported. 3

Although rare, lymphoma is an important consideration in the differential diagnosis for tumors involving the spine. Surgical intervention is often necessary to relieve spinal cord compression and to make a histologic diagnosis. Treatment includes radiation and chemotherapy. Patients with primary spinal epidural lymphoma tend to have a better prognosis than patients with systemic lymphoma involving the epidural space, as well as patients with metastatic carcinoma. 3

References

  1. Hameed, Meera: Small Round Cell Tumors of Bone. Arch Pathol Lab Med (2007) 131: 192-204.
  2. Louis D.N., Ohgaki H., Wiestler O.D., Cavenee W.K. (Eds.): WHO Classification of Tumors of the Central Nervous System. IARC: Lyon 2007.
  3. Cugati G, Singh M, Pande A, et al. Primary spinal epidural lymphomas. Journal of Craniovertebral Junction and Spine (2011) 2(1): 3-11.

 

Marcus, Chelsea_099-Edit

Chelsea Marcus, MD is a third year resident in anatomic and clinical pathology at Beth Israel Deaconess Medical Center in Boston, MA and will be starting her fellowship in Hematopathology at BIDMC in July. She has a particular interest in High-grade B-Cell lymphomas and the genetic alterations of these lymphomas.

To Be (MDS) or Not To Be? The Conundrum of Cytoplasmic Vacuolation in Hematopoietic Precursors

Every hematopathologist and pathology trainee knows to be wary of the myriad of causes that could mimic the dysplastic changes seen in marrows involved by MDS. Many times morphology alone, without genetic or cytogenetic evidence of clonality can be tricky. The list of things that can recapitulate changes seen in MDS seems to grow longer every day – and with it the length of our ‘canned comments’ on ruling out reactive causes of dysplasia. Within the recent past, two bone marrow biopsies crossed my microscope, both sent to ‘rule out’ MDS. Both had almost identical morphologic findings, but very different diagnoses. Here are some representative images from the marrow aspirates and iron stains:

mds
Figure 1. Representative Wright-Giemsa stained cells from Case 1 (A and B) with accompanying iron stain (C) showing numerous ring sideroblasts.  Representative Wright-Giemsa stained cells from Case 2 (D) with accompanying iron stain (E) showing some ring sideroblasts. 

Discussion

Images A through C come from case 1, a 67-year-old woman with a past medical history of non-alcoholic steatohepatitis (NASH) complicated by hepatic encephalopathy and recurrent ascites who underwent bone marrow biopsy for new onset pancytopenia with transfusion-dependent anemia. The marrow was slightly hypercellular for age and showed progressive trilineage maturation. Granulocytic and erythroid progenitors did not reveal quantitatively significant dysplasia. The one dysplastic megakaryocyte identified is pictured here (panel A). Interestingly many erythroid and granulocytic precursors showed cytoplasmic vacuolation (panel B showing granulocytic vacuolation). An iron stain (panel C) revealed 44% ring sideroblasts. Case 2 is represented in images D and E and was from a 64-year-old man with no significant past medical history who presented with lethargy and anemia. This marrow was also slightly hypercellular for his age and showed borderline-significant dysplasia in megakaryocytic maturation. Granulopoiesis and erythropoiesis were unremarkable except for cytoplasmic vacuolations in many cells (panel D). An iron stain showed 8% ring sideroblasts (panel E).

Both cases were signed out descriptively, urging the clinician that we needed to rule out reactive causes of dysplasia before a definitive diagnosis of MDS could be rendered. In both cases we suggested waiting for the cytogenetics results for a more comprehensive analysis. Additionally, we recommended testing for serum copper since copper deficiency can be the cause of dysplastic morphology, cytoplasmic vacuolation, and ring sideroblasts.

Case 1 revealed markedly diminished copper and normal cytogenetics. Copper replenishment was curative. Case 2 revealed normal copper levels and a complex karyotype that contained numerous MDS-associated abnormalities confirming the clonal, and therefore malignant nature of these changes. Despite being almost identical morphologically, these case were diagnostically and prognostically poles apart.

Copper is an element that serves as a micronutrient required for hematopoiesis. It’s presence in many readily available foods including meat, fish, nuts, and seeds renders diet-related copper deficiency a rare phenomenon. Zinc-supplementation is one of the causes of copper deficiency in published reports. Copper deficiency has been well documented to mimic dysplastic changes seen in MDS; but these morphologic findings and cytopenia are reversible. Characteristically, cytoplasmic vacuolation is an important morphologic clue that there could be an underlying paucity of serum copper.  Another aspect of copper deficiency is the presence of ring sideroblasts which also can mean MDS. It is very important to consider this differential diagnosis when dealing with marrow specimens sent to rule out MDS. This Lablogatory post highlights the significant overlap between presentation and morphologic findings between MDS and copper deficiency supporting the notion that a high index of suspicion, good communication, stat copper levels, and cytogenetics or MDS FISH studies are very helpful in delineating benign from malignant.

References

  1. Dalal N. et al. Copper deficiency mimicking myelodysplastic syndrome. Clin Case Rep. 2015 May; 3(5): 325–327.
  2. Willis M.S. Zinc-Induced Copper Deficiency: A Report of Three Cases Initially Recognized on Bone Marrow Examination. AJCP. 2005 Jan; 123(1): 125–131
  3. D’Angelo G. Copper deficiency mimicking myelodysplastic syndrome. Blood Res. 2016 Dec; 51(4): 217–219.
  4. Karris S and Doshi V. Hematological Abnormalities in Copper Deficiency. Blood 2007 110:2677

 

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-Kamran M. Mirza, MD PhD is an Assistant Professor of Pathology and Medical Director of Molecular Pathology at Loyola University Medical Center. He was a top 5 honoree in ASCP’s Forty Under 40 2017. Follow Dr. Mirza on twitter @kmirza.

Hematopathology Case Study: A 45 Year Old Male with Mediastinal Mass

Case History

A 45 year old male underwent a chest MRA for aortic dilation due to his history of an aneurysmal aortic root. Upon imaging, an incidental anterior mediastinal mass was seen that measured 4.0 cm. In preparation for an upcoming cardiac surgery, the patient underwent a thymectomy with resection of the mass. The sample is a section from the mediastinal mass.

Diagnosis

HVCD-HE-2x
H&E, 2x
HVCD-HE-4x
H&E, 4x
HVCD-HE-lollipop
H&E, 10x. Green Arrows: “lollipop” germinal centers
HVCD-HE-twinning
H&E, 10x. Red arrow: focal “twinning” of germinal centers

Sections show an enlarged lymph node with several follicles demonstrating atrophic-appearing germinal centers which are primarily composed of follicular dendritic cells. These areas are surrounded by expanded concentrically arranged mantle zones. Focal “twinning” of germinal centers is present. Additionally, prominent centrally placed hyalinized vessels are seen within the atrophic germinal centers giving rise to the “lollipop” appearance.

By immunohistochemistry, CD20 highlights B-cell rich follicles while CD3 and CD5 highlight abundant T-cells in the paracortical areas. CD10 is positive in the germinal centers while BCL2 is negative. CD21 highlights expanded follicular dendritic meshwork. CD138 is positive in a small population of plasma cells and are polytypic by kappa and lambda immunostaining. HHV8 is negative. MIB1 proliferation index is low while appropriately high in the reactive germinal centers.

Overall, taking the histologic and immunophenotypic findings together, the findings are in keeping with Castleman’s disease, hyaline vascular type. The reported clinical and radiographic reports suggest a unicentric variant.

Discussion

Castleman’s disease comes primarily in two varieties: localized or multicentric. The localized type is often classified as the hyaline vascular type (HVCD). Demographically, it’s a disease of young adults but can be found in many ages. The most common sites for involvement are the mediastinal and cervical lymph nodes.

The classic histologic findings of HVCD involve numerous regressed germinal centers with expanded mantle zones and a hypervascular interfollicular region. The germinal centers are predominantly follicular dendritic cells and endothelial cells. The mantle zone gives a concentric appearance, often being likened to an “onion skin” pattern. Blood vessels from the interfollicular area penetrate into the germinal center at right angles, giving rise to another food related identifier, “lollipop” follicles. A useful diagnostic tool is the presence of more than one germinal center within a single mantle zone.

The differential diagnosis of HVCD includes late stage HIV-associated lymphadenopathy, early stages AITL, follicular lymphoma, mantle cell lymphoma, and a nonspecific reactive lymphadenopathy. A history of HIV or diagnostic laboratory testing for HIV would exclude the first diagnosis. AITL usually presents histologically as a diffuse process but atypia in T-cells with clear cytoplasm that co-express CD10 and PD-1 outside of the germinal center are invariably present. EBER staining may reveal EBV positive B immunoblasts in early AITL, which would be absent in HVCD. The most challenging differential would include the mantle zone pattern of mantle cell lymphoma. Flow cytometry revealing a monotypic process with co-expression of cyclin D1 on IHC would further clarify the diagnosis.1

Overall, unicentric Castleman’s disease is usually of the hyaline vascular type. Surgical resection is usually curative in these cases with an excellent prognosis.2

 

References

  1. Jaffe, ES, Harris, NL, Vardiman, J, Campo, E, Arber, D. Hematopathology. Philadelphia: Elsevier Saunders, 2011. 1st ed.
  2. Ye, B, Gao, SG, Li, W et al. A retrospective study of unicentric and multicentric Castleman’s disease: a report of 52 patients. Med Oncol (2010) 27: 1171.

 

PhillipBlogPic-small

-Phillip Michaels, MD is a board certified anatomic and clinical pathologist who is a current hematopathology fellow at Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA. His research interests include molecular profiling of diffuse large B-cell lymphoma as well as pathology resident education, especially in hematopathology and molecular genetic pathology.

Hematopathology Case Study: A 69-Year-Old Man Presenting with Marked Thrombocytopenia One Year after Bone Marrow Transplantation

Case history

The patient is a 69-year-old man with a history of high-risk MDS (MDS-MLD-RS) diagnosed 1 year prior to his current visit. He was successfully treated with chemotherapy and bone marrow transplantation. For the next year, several marrow examinations were normal and chimerism analysis revealed >98% donor cells. Currently, he presents with vague symptoms and a CBC demonstrates marked thrombocytopenia of 4K/μL.  The low platelet count is initially thought to be related to GVHD; however, a bone marrow examination is performed to assess the status of his disease.

DiGug1.png
Wright-Geimsa, 2X
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Wright-Geimsa, 100X
DiGug3
E-Cadherin IHC, 4X

Microscopic Description

Examination of the bone marrow reveals a markedly hypercellular marrow for age with a proliferation of abnormal erythroid cells comprised of sheets of immature and maturing red cell precursors with basophilic cytoplasm. There is a marked increase in larger cells with deeply basophilic cytoplasm, prominent nucleoli, dispersed chromatin, perinuclear hoffs, and a high nuclear to cytoplasmic ratio consistent with pronormoblasts. These pronormoblasts comprised 31% of a 500-cell cell count. Additionally, the background marrow revealed a total of 81% erythroid precursors with marked morphologic atypia and dyspoiesis. Significant dysmegakaryopoiesis is noted. There is no significant increase in myeloid blasts.

Immunophenotyping

Immunohistochemical staining for E-cadherin, CD61 and CD34 is performed. These stains confirm no increase in CD34 positive blasts. CD61 highlights numerous dyspoietic megakaryocytes with widely separated nuclear lobes. E-cadherin staining is impressive, with over 80% of marrow cellularity shown to be comprised of E-cadherin positive erythroid cells.

Diagnosis

The patient’s history of MDS with current dyspoiesis, presence of >80% immature erythroid precursors with >30% proerythroblasts is diagnostic of Acute Myeloid Leukemia, NOS (Pure Erythroid Leukemia) per 2017 revision of the World Health Organization classification of myeloid neoplasms.

While successive chimerism reports thus far had shown >98% donor cells, the chimerism associated with this marrow biopsy reveals a decrease in the percentage of donor cells to 44% confirming the relapsed nature of his myeloid malignancy.

Discussion

Di Guglielmo syndrome, known as M6 leukemia in the FAB classification, was named after Giovanni Di Guglielmo, an Italian hematologist who first characterized the disease in 1917. After a few iterations in different classification schemes, the 2008 WHO Classification characterized two types of ‘erythroleukemia’ the erythroid/myeloid type and the pure erythroid leukemia. The former category of erythroid/myeloid type was removed in the 2017 update of the WHO classification with cases meeting criteria for that diagnosis now falling under the category of MDS. ‘Pure Erythroid Leukemia’ remains, and comes under the AML, NOS category, requiring >80% erythroid progenitors with > 30% proerythroblasts.

An extremely rare leukemia, PEL usually occurs as a progression of previous MDS and very uncommonly as de novo disease. Morphologically, PEL reveals proerythroblasts with deeply basophilic, agranular cytoplasm which is usually vacuolated. Occasionally, smaller ‘blasts’ with scant cytoplasm may resemble lymphoblasts. PEL is an exception to the rule of needing 20% ‘myeloid blasts’ to make an acute leukemia, since often the true myeloblast count is low.

In trephine core biopsies erythroid progenitors may take up an intra sinusoidal growth pattern with a sheet-like arrangement and typically reveal some element of background dysmegakaryocytopoiesis. When PEL lacks specific erythroid differentiation, it may be difficult to differentiate from other types of AML such as Acute Megakaryoblastic Leukemia. Park and colleagues recently categorized some under reported morphologic features of PEL and recurrent cytogenetic abnormalities associated with this disease. These findings included (but were not limited to) a broad morphologic spectrum of erythroblast morphology from undifferentiated blasts to proerythroblasts. They reported bone marrow tumour necrosis in trephine biopsies in over 70%  of their cases. Of the cases wherein karyotyping was available, there was a highly complex and monosomal karyotype noted involving the TP53 gene locus.

PEL is associated with an aggressive course with a median survival of 3 months.

References

  1. Arber DA, Orazi A, Hasserjian R, Thiele J, Borowitz MJ, Le Beau MM, Bloomfield CD, Cazzola M, Vardiman JW. The 2016 revision to the World Health Organization (WHO) classification of myeloid neoplasms and acute leukemia. Blood. 2016 Jan 1:blood-2016.
  2. Wang W, Wang SA, Jeffrey Medeiros L, Khoury JD. Pure erythroid leukemia. American journal of hematology. 2017 Mar 1;92(3):292-6.
  3. Park DC, Ozkaya N, Lovitch SB. Acute leukaemia with a pure erythroid phenotype: under-recognized morphological and cytogenetic signatures associated universally with primary refractory disease and a dismal clinical outcome. Histopathology. 2017 Aug;71(2):316-321. doi: 10.1111/his.13207. Epub 2017 May 5.

 

Mike

-Michael Moravek, MD is a 2nd year anatomic and clinical pathology resident at Loyola University Medical Center. Follow Dr. Moravek on twitter @MoravekMD.

Mirza-small

-Kamran M. Mirza, MD PhD is an Assistant Professor of Pathology and Medical Director of Molecular Pathology at Loyola University Medical Center. He was a top 5 honoree in ASCP’s Forty Under 40 2017. Follow Dr. Mirza on twitter @kmirza.