Hematopathology Case Study: A 72 Year Old Female with History of Lung Adenocarcinoma

Case history 

A 72 year-old female with a history of stage IA lung adenocarcinoma diagnosed in 2009 s/p resection underwent a surveillance CT scan of the chest which revealed an enlarged right upper lobe paramediastinal lung nodule. A subsequent MRI of the abdomen and PET scan revealed mediastinal lymphadenopathy with numerous boney lesions. Due to the prior history of lung cancer, a right iliac bone biopsy was performed.

Diagnosis

myesar-he-10
H&E, 10x
myesar-he-20
H&E, 20x
myesar-he-50
H&E, 50x
myesar-cd-45
CD45
myesar-cd-117
CD117
myesar-cd-34
CD34
myesar-cd-68
CD68
myesar-cd-56
CD56
myesar-mpo
MPO
myesar-cd-43
CD43

Sections of bone show an extensive intramedullary infiltration by large cells with moderate amounts of cytoplasm, irregular nuclear contours, moderately condensed chromatin and some cells with inconspicuous nucleoli.

By immunohistochemistry, the neoplastic cells are immunoreactive for CD45, MPO, CD68, CD56, and CD43. The cells are negative for cytokeratins, TTF-1, CD20, CD10, PAX5, BCL6, MUM1 and CD79a. CD3 and CD5 highlight rare scattered T-cells.

Overall, in the context of multiple osseous lesions, these findings are representative for a myeloid sarcoma.

Discussion 

Myeloid sarcoma is a tumor mass consisting of myeloid blasts with or without maturation occurring at any site other than the bone marrow. Infiltration of blasts at any site are not classified as a myeloid sarcoma unless there is effacement of tissue architecture. Frequent sites for involvement by a myeloid sarcoma include skin, lymph node, gastrointestinal tract, bone, soft tissue, and testis.

Detection of a myeloid sarcoma is considered as an equivalent diagnosis of acute myeloid leukemia. It may precede or coincide with AML as well as be a presenting finding in those that relapse from AML.

Morphologically, the blasts may or may not show features of maturation and efface the architecture of the involved site. Immunophenotypically, CD68 is considered the most commonly expressed marker followed by MPO, CD117, lysozyme, CD34, TdT, CD56, CD30, glycophorin and CD4. Interestingly enough, CD123 may be expressed in those cases that also have inv(16). It must be emphasized that those cases that meet criteria for a mixed phenotypic acute leukemia (MPAL) cannot be classified as a myeloid sarcoma.

By cytogenetics, 55% of myeloid sarcomas have aberrant cytogenetic findings including monosomy 7, MLL rearrangements, inv(16), and other chromosomal changes. In the pediatric population, t(8;21) may be observed and is less frequent in adults. NPM1 is mutated in 16% of cases.

Lastly, the differential diagnosis should be kept broad in cases that appear lymphoid in nature yet do not mark appropriately. It is often expressed that the primary morphologic differential is a lymphoma, including lymphoblastic lymphoma, Burkitt lymphoma, diffuse large B-cell lymphoma, blastic plasmacytoid dendritic cell neoplasm, and other small round blue cell tumors of childhood.

Reference

  1. Swerdlow SH, Campo E, Harris NL, et al.  WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues. Lyon, France: IARC Press; 2008

 

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 68 Year Old Man with Dyspnea on Exertion

Case History

A 68 year old male with no significant past medical history who enjoys long distance cycling presented to an outside emergency department with dyspnea on exertion. Laboratory values at the outside facility showed profound anemia (Hb 10 g/dL) and physical exam revealed lymph adenopathy. The patient was discharged but presented again to his primary care physician with profound dyspnea on exertion, especially after climbing one flight of stairs. Of note, his anemia had worsened with a new Hb of 7 g/dL. For evaluation of the anemia, the patient had a Coomb’s test and it was positive, overall consistent with cold agglutinin disease. For evaluation of the lymphadenopathy, a CT abdomen and chest revealed celiac, portocaval, mesenteric and retroperitoneal lymphadenopathy as well as mild splenomegaly. Due to these findings, the patient presented to Beth Israel Deaconess Medical Center for further evaluation and biopsy of a retroperitoneal lymph node.

A core needle biopsy of a retroperitoneal lymph node was obtained per the recommendation of hematology/oncology.

Diagnosis

AITL-1
H&E, 10X
AITL-2
H&E, 20X
AITL-3
H&E, 50X
AITL-4
CD3
AITL-5
CD20
AITL-6
CD10
AITL-7
CD4
AITL-8
CD7
AITL-9
CD21
AITL-10
Ki-67
AITL-11
EBER ISH
AITL-12
PD1
AITL-13
CXCL13

The core needle biopsy material demonstrated a lymphoid population that was polymorphic in appearance with medium to large sized lymphocytes with moderate amounts of pale cytoplasm, irregular nuclei, vesicular chromatin, and some cells with prominent nucleoli. The background cellular population is composed of a mixed inflammatory component including small lymphocytes, scattered neutrophils, eosinophils, and histiocytes.

By immunohistochemistry, the medium to large sized cells with pale cytoplasm are positive for CD3, CD2, CD4, and CD5 with complete loss of CD7. CD20 highlights scattered background B-cells. CD21 is positive in disrupted follicular dendritic meshworks. CD10 and BCL6 are negative in neoplastic cells. PD1 is positive in neoplastic cells with a subset co-expressing CXCL13. By Ki-67 immunostaining, the proliferation index is 50-70%. By in situ hybridization for Epstein-Barr virus encoded RNA, a subset of cells are positive.

Overall, with the morphologic and immunophenotypic features present, the diagnosis is that of angioimmunoblastic T-cell lymphoma.

Discussion

Angioimmunoblastic T-cell lymphoma (AITL) is one of the most common types of peripheral T-cell lymphoma and accounts for 15-20% of T-cell lymphoproliferative disorders and 1-2% of all non-Hodgkin lymphomas. Clinical features include presentation with late stage disease with associated generalized lymphadenopathy, hepatosplenomegaly, systemic symptoms, and polyclonal hypergammaglobulinemia. Of note, this patient did have an SPEP that was within normal limits. Other findings, although less common, include effusions and arthritis. Laboratory findings often include cold agglutinins with hemolytic anemias, a positive rheumatoid factor (RF), and anti-smooth muscle antibodies. A hallmark of AITL is the expansion B-cells positive for EBV is seen, which may be an indicator of underlying immune dysfunction. The clinical course is often aggressive with a median survival of less than three years and often succumb to infectious etiologies because of an immune dysregulation.1

The pathogenesis and relation to other TFH neoplasms of PTCL, NOS is poorly understood. Recent literature indicates dysregulation in key pathways, including the CD28 and TCR-proximal signaling genes, NF-kappaB/NFAT pathway, PI3K pathway, MAPK pathway, and GTPases pathway.2 The complexity of these pathways has long been an issue for TFH lymphoproliferative disorders and has provided insight to potential molecular signatures (see figure 1 adapted from Vallois 2016).

AITL-14
Figure 1 from Vallois 2016

Another recent publication provided additional information regarding molecular insights. Confirmed mutational analyses reveals a high proportion of cases carry a TET2 mutation with less frequent changes in DNMT3A, IDH2, RHOA, and PLCG1. Specifically, RHOA, PLCG1, and TNFRSF21 encode proteins critical for T-cell biology and most likely promote differentiation and transformation into an aggressive clinical course (see figure 2 adapted from Wang 2017).3

AITL-15
Figure 2 adapted from Wang 2017

Overall, AITL is an uncommon TFH cell derived lymphoproliferative disorder characterized by a TFH immunophenotype, expanded and arborizing high endothelial venules, expansion of the follicular dendritic cell meshworks, and EBV positive B-cells in a background of a polymorphic infiltrate. Although it is hypothesized that the underlying mechanism of neoplasia is related to immune dysfunction, new molecular insights have demonstrated that multiple events occur ranging from early molecular changes to later acquired mutations that allow for malignant transformation.

References

  1. Swerdlow, S., et al., WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, 4th. ed., IARC press: 2008
  2. Vallois, D., et al. “Activating mutations in genes related to TCR signaling in angioimmunoblastic and other follicular helper T-cell-derived lymphomas,” 2016; 128(11): 1490-1502.
  3. Wang, M., et al., “Angioimmunoblastic T cell lymphoma: novel molecular insights by mutation profiling,” 2017; 8(11): 17763-17770.

 

 

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.

Show Us Some Skin

Which epidermal layer is indicated by the arrow?

  • A. Stratum corneum
  • B. Stratum germinativum
  • C. Stratum granulosum
  • D. Stratum lucidum
  • E. Stratum spinosum

Skin1

 

The answer is E, stratum spinosum. The stratum spinosum, also known as the prickle cell layer of the skin, is often several cell layers deep, and is located immediately above the stratum germinativum. Cells in this layer are polygonal, and are connected to each other by numerous desmosomes. During fixation, the cell membrane retracts around desmosomal contact points, giving the cells a prickly appearance. The cells contain many bundles of intermediate filaments as well as keratinosomes, which are membrane-bound granules thought to deposit a “toughening” layer on the surface of the cell membrane.

Skin2

 

The stratum germinativum (also known as the basal layer) is composed of a single layer of cells adjacent of the basal lamina. The cells are tall cuboidal or columnar, and are connected to the basement membrane by hemidesmosomes, and to other cells by desmosomes. Cells in the basal layer are mitotically active, and contain numerous polyribosomes and intermediate filaments.

Skin3

 

The stratum granulosum is 3 to 5 cell layers thick, and is composed of flattened, polygonal cells arranged with the long axis parallel to the basement membrane. The cytoplasm of these cells contains numerous basophilic granules, called keratohyalin granules, which are thought to be keratin precursors.

The stratum lucidum is not truly a distinct layer of skin, but rather a staining artifact. It is visible in some sections of thick skin as a glassy-appearing, eosinophilic artifact at the bottom of the stratum corneum. It is not present in this particular image of epidermis.

Skin4

 

The stratum corneum is the outermost layer of skin. The thickness of this layer varies considerably from region to region in the body. The cells of this layer are dead, flattened, and fused together, with completely keratinized cytoplasm.

Skin5

 

Krafts

-Kristine Krafts, MD, is an Assistant Professor of Pathology at the University of Minnesota School of Medicine and School of Dentistry and the founder of the educational website Pathology Student.

Routine Pap Smear from a 33 Year Old Woman

You are reviewing a routine Papanicoloaou smear from a 33 year-old female. She has no complaints and appears healthy. A representative field from her Pap smear is shown here. What organism is the most likely cause of the morphologic changes seen here?

pap1

  1. Chlamydia trachomatis
  2. Human papillomavirus
  3. Trichomonas vaginalis
  4. Leptothrix
  5. Gardnerella vaginalis

 

 

The diagnosis in this case is Chlamydial infection. Genital infection by Chlamydia trachomatis is the most common sexually transmitted disease in the world. In women, chlamydial infection of the cervix is frequently asymptomatic, as it was in this patient. If untreated, however, the infection can lead to pelvic inflammatory disease, infertility and ectopic pregnancy.

Chlamydia trachomatis is a tiny, gram-negative bacterium that exists in two different forms: the elementary body, which is the infectious form, and the reticulate body, which is the replicative form. While Chlamydial organisms are too small to be visible with a gram stain, large, glassy inclusions containing both reticulate bodies and elementary bodies are occasionally clearly visible within cells, as seen in the squamous epithelial cells in this image (see arrows).

pap2

 

Krafts

-Kristine Krafts, MD, is an Assistant Professor of Pathology at the University of Minnesota School of Medicine and School of Dentistry and the founder of the educational website Pathology Student.

The Value of Electives (Both Internal and External) During Pathology Residency

It’s been a while since my last blog. I haven’t had as much time and energy as I would like this past year. For now, I’ll just say…appreciate all that your chief residents do because much more time and effort lies beneath the surface than everyone is able to see.

But the topic for this blog is the value of electives during pathology residency. Our programs vary with respect to electives in terms of number and ability to take them externally or not. My previous program had five electives that could be taken internally or externally. However, external electives did not receive salary support and I didn’t take any electives although I could’ve during my two years in Chicago. Since we had a decent number of electives, many residents scheduled them internally during fourth year to have lighter months to study for boards although a handful did utilize them during earlier years for external electives.

My current program has two and we do receive salary support with external electives. For my first, I had an extra month of hematopathology internally because I wanted to see another perspective on one of my chosen subspecialties. Internal electives are good to spend more focused time in an area of subspecialty interest that you may have for fellowship. It also allows for the opportunity to develop deeper relationships with the faculty who will most likely be writing your letters of recommendation for that fellowship. They may also provide you with the opportunity to become more involved in research and/or publications (eg – book chapters, case reports, research articles) with a mentor and these are all helpful in enhancing your fellowship and future job applications and build up your CV.

Currently, I’m on an external elective at the institution where I’ll do both my hematopathology and molecular genetic fellowships. I’m laying the groundwork for molecular hematopathology research now that hopefully results in data analysis over the ensuing months to culminate in an abstract submission for the American Society of Hematology (ASH) which has a deadline only a month after I start fellowship. I also want to use this time away to get to know people at my future program better, prepare for my eventual move here, and study for boards. Hopefully, I’ll also get a sense of the daily work flow as I am also attending signouts and intra- and interdepartmental conferences so that I can manage my time as efficiently as I can from day 1 of fellowship. I really like the culture and people here, but that’s subject matter for a future blog. I also am enjoying the benefits of attending inter-program activities as TMC is the largest medical center in the world with active interaction and collaboration between member hospitals. Not so much in my case since I obtained both my consecutive fellowships last year as a PGY-3, but for many, the value of an early external elective is that it can be seen it as an “audition” rotation to obtain a desired fellowship. You may even be able to ask for an interview before you finish (which saves you time and money). I also have some friends who were offered fellowship spots at the end of their elective rotation because they impressed the fellowship director. Obtaining fellowship positions is pretty competitive and there tends to be fewer spots than there are for residency. And in many cases, positions are not even available if an internal candidate is chosen early (even during their PGY-1) so anything to augment your fellowship application is a plus.

Now that I’ve mentioned external electives, I’d like to give some advice on setting up an external elective. First, start as EARLY as possible! Even a year or more before isn’t too early to ask about getting the ball rolling. Start preparing and updating your CV from your PGY-1 as you’ll need this for both external elective and fellowship applications. Scan and keep a PDF of all your vaccinations and work-related health requirements (eg – PPD/Quantiferon results, flu vaccine, hepatitis B testing, MMR and hepatitis B antibody titers, and N-95 fit testing) as well because its likely you’ll also have to include this in your external elective application.

I initiated the elective rotation request about a half year prior to the actual rotation. And even then, that was not early enough and everything came down to the wire. It’s far more complicated than when we applied for elective rotations as a medical student and takes much more time. Since we are now physicians, you are more than likely required to have at least a medical permit in that state to rotate and this process can take a while. Also the back-and-forth between program coordinators and the respective GME departments can appear glacial at times, and in my case, was the main cause of delay. I hit several delays at obtaining paperwork (especially between Christmas and New Year’s when many staff were off at both programs, my medical school, and the Texas Medical Board where I needed paperwork from). It can be time-consuming to have to make multiple phone calls, and often, the process cannot be completed until its antecedent step has been approved. I know residents who have had to postpone external rotations because paperwork between GME departments (eg – PLAs or malpractice agreements) were not in place in time. Maintaining constant and open communication between all parties involved is a must and sometimes easier said than done the more people that are involved.

In addition to obtaining the state medical permit (which generally requires an application fee; in my case, $135), there may be other requirements that are also time-consuming and financially expensive. You may be required to do pre-employment-type health screening (in my case, a $36 urine drug screen) at your own cost as you are not a true employee. I also had to become ACLS certified (at $120, despite being BLS certified and a former American Red Cross CPR instructor). But since I’m going to be a fellow here, I can get it reimbursed through my GME funds and would have to do it later anyways so I might as well do it now. But if you are not doing an elective at your future fellowship institution, it’s good to find out what items may incur cost in your application for your elective since you are not likely to get reimbursed and so you can decide whether those expenses are acceptable. One way to defray costs is to apply for grants such as the ASCP subspecialty grant which is administered to six residents twice a year (Jan/Aug). In fact, the next deadline is this Friday, Jan 15th! You can find more information on how to apply at http://www.ascp.org/Residents/Resident-Grants.

 

Chung

-Betty Chung, DO, MPH, MA is a fourth year resident physician at Rutgers – Robert Wood Johnson University Hospital in New Brunswick, NJ.

You Make the Diagnosis: A 62 Year Old Female with Hemoptysis and Fatigue

A 62-year-old female presents with hemoptysis and fatigue. A large mass is found adjacent to the right main bronchus. A representative field is shown here. What is the diagnosis?

smallcell

  1. Invasive adenocarcinoma
  2. Squamous cell carcinoma
  3. Adenocarcinoma in situ (formerly bronchoalveolar carcinoma)
  4. Small cell carcinoma
  5. Large cell carcinoma

 

 

The diagnosis in this case is small cell carcinoma. Also called “oat cells,” the malignant cells in this tumor tend to be round to somewhat elongated in shape, with the typical “salt-and-pepper” chromatin of neuroendocrine tumor cells. The cells are often so closely apposed that their nuclear contours show a characteristic “molding” effect. Small cell carcinoma is a fast growing tumor (note the large mitotic figure at 4 o’clock) with a poor prognosis.

 

Krafts

-Kristine Krafts, MD, is an Assistant Professor of Pathology at the University of Minnesota School of Medicine and School of Dentistry and the founder of the educational website Pathology Student.

 

 

Tumor Boards and Multidisciplinary Conferences (MDC)

Even if we are not as visible to the patients that we care for as other physicians, pathologists are amazing! Of course, I admit that I’m biased since I am a pathology resident but, this does not make this fact any less true. Others may not always realize that pathologists often have to make life altering diagnoses on the most miniscule of tissue samples. Or that we need to incorporate clinical histories, imaging, and previous clinical test and pathology results just as much as the primary clinician, I’ll dare say, sometimes, even more so, since we often do not have the opportunity to talk with the patient face-to-face. And that in the future, especially as precision medicine develops an increasing foothold in the treatment decision making process, we should, and will be, taking more active leadership roles within multidisciplinary teams.

One of the places where I feel that pathologists can show their value to the patient care team is in the multidisciplinary conference (MDC) setting. These can include tumor boards where we discuss specific patient cancer cases or other interdepartmental conferences where we explore an area of common interest that doesn’t necessarily have to be neoplastic. “Doctor” is derived from the Latin word, docere, which means “to teach” and it is within MDC’s that we can shine as teachers. It is impossible to learn about you need to know in medical school in terms of patient care. Not only is the fount of knowledge ever increasing but also our training directs us toward subspecialization since the volume knowledge is so vast, we have to choose which areas we will spend more time mastering.

Way back in the day, surgery residents had to spend significant time (often at least six months) rotating on the surgical pathology service. I find that these more experienced attendings are often the ones who scrub out and sit with our pathologists at the multi-headed scope during frozen sections. And they are also the ones who can make the surgical pathology diagnosis and know the staging summaries even better than junior, and even some senior, pathology residents. But training requirements change. Most of the other clinical physicians we will interact with as colleagues were not trained in this manner.

One of the reasons I chose hematopathology was because I enjoy the daily increased face-to-face interaction I experienced while on this rotation. At most of the hospital sites I’ve trained (four at my previous program and two at my current program), hem/onc physicians and fellows often make the trek to the pathology department to discuss patient cases with the hematopathologist, especially over the microscope. They had some idea of what they were looking at, too. In fact, at a couple of the programs I interviewed (Hopkins and UW), hem/onc physicians are, or were in past in the case of UW, responsible for reading the liquid specimens (peripheral blood smears and aspirates). They also often had multiple interdisciplinary conferences – leukemia, lymphoma, coagulation/benign heme.

But, since I’m on a surgical pathology rotation right now, I was thinking about when we interact most with our surgeons – and I think that is during tumor board. A few of the “old school” surgeons will scrub out and come to the department to look over a frozen with us but most often than not, this is not the case. But during tumor boards, there is always active discussion which includes the pathology in order to come to a treatment decision on not-so-straightforward cases. And these are opportunities to demonstrate just how important the pathologist is to the process. At least in the difficult cases, we do not merely write out diagnoses for other doctors to read and move on without us to treat the patient. It is in these moments when we not only educate but can also actively participate in helping to direct care. But in order to do so, we need to be able to integrate the clinical, epidemiologic, morphologic, radiologic, ancillary diagnostic, and prognostic (lots of “-ogics” there) factors along with know the potential treatment alternatives. We don’t just deal with the morphologic and leave everything else to the referring physicians…at least, if you want to be the best pathologist that you can be. This is also the time when we can leave a lasting impression on other trainees (medical students, residents, and fellows) about how a pathologist can contribute when added to the team mix so that they will be more apt to seek out and work together with pathologists when they become attending physicians.

We are the physicians who understand the intricacies and implications of many of the ancillary tests if we understand well how they are performed and why and also what can cause erroneous or false positive/negative results. I think that I learned a lot of those types of things through serving as an accredited lab inspector (or you can help with your department’s lab self-inspections) and also by being more pro-active during my CP rotations to work with the lab staff and not just sit at my desk and read a book (or study for boards). And we can help guide other physicians regarding which tests are useful for specific situations and which tests really won’t impact prognosis or treatment management. So, be deliberate during your rotations! Try to understand the “big picture” and how important we can be (and really are) in the patient safety and care process! I think that tumor boards and interdepartment MDC’s are a great venue for us to showcase the “true” contributory potential of what pathologists to the patient care team.

Chung

-Betty Chung, DO, MPH, MA is a third year resident physician at Rutgers – Robert Wood Johnson University Hospital in New Brunswick, NJ.