Month: June 2018

The Syncytial Variant: A High-Risk Subgroup Amongst the Traditionally Well-Behaved Classic Nodular Sclerosis Hodgkin Lymphomas

Lymphoid neoplasias are traditionally categorized as Hodgkin Lymphomas or Non-Hodgkin Lymphomas. Hodgkin Lymphomas are typically characterized by both expansive reactive lymphocytes and a paucity of the interspersed, malignant Reed-Sternberg (RS) Cell. These RS cells are large neoplastic B-Cell variants with ‘owl-eye’ nucleoli within multilobed nuclei. The background reactive lymphocytes are non-neoplastic cells drawn by secreted RS cytokines (IL-5, IL-6, IL-13, TNF, and GM-CSF), which often result in presenting B symptoms (fevers, chills, and night sweats). Histiocytes, granulocytes, and plasma cells are also commonly identified. Confirmatory immunohistochemistry staining for RS cells involves CD30 positivity, CD15 positivity, and negativity for CD20 and LCA (CD45) staining. The two major types of Hodgkin Lymphoma are recognized as Nodular Lymphocyte Predominant Hodgkin Lymphoma (NLPHL) and Classic Hodgkin Lymphoma (CHL). In NLPHL, B-Cell immunophenotype is generally preserved and is histologically recognized by a nodular predominance of small lymphocytes and RS cell variants, called lymphocyte predominant (LP) or popcorn cells (formerly called L&H cells for lymphocytic and/or histiocytic RS cell variants), which exhibit muted, lobed nuclei and smaller nucleoli. The Classic Hodgkin Lymphomas are categorized histologically as Nodular Sclerosis CHL (NSCHL), Lymphocyte Rich CHL (LRCHL), Mixed Cellularity CHL (MCCHL), and Lymphocyte Depleted CHL (LDCHL).

Nodular Sclerosis Classic Hodgkin Lymphoma (NSCHL) comprises over 70% of all CHL and is characterized by broad, fibroblast-poor collagen banding surrounding at least one nodule and by RS cells with lacunar morphology. The RS cells tend to have a larger amount of cytoplasm than those in other types of classic Hodgkin lymphoma. When fixed in formalin, this excess cytoplasm causes their membranes to retract so that the cells seem to be sitting in lacunae. Typically, EBV association is uncommon, CD30 is almost always expressed, CD15 is expressed in 75-85% of cases, and PAX5 is weakly positive. Most cases do not express T-Cell antigens (CD4, CD3, CD8), but when they do (~5% of cases), they can be difficult to distinguish from ALK-negative Anaplastic Large Cell Lymphomas (PAX5 positivity can help to rule out ALCL). True T-cell marker expression on RS cells has been seen (usually weak) and is associated with a poorer prognosis.

Two histologic variants of NSCHL have been proposed: a fibrocystic variant (FV) and a syncytial variant (SV). The FV contains abundant fibroblasts and histiocytes in the setting of difficultly identified RS cells. The SV describes the finding of RS cells in prominent, sheet-like aggregates forming cohesive lacunar nests in the center of nodules (Figure 1). The SV represents 5-16% of all cases of NSCHL (Ben-Yehuda-Salz et al. 1990), though some suspect it may be as high as 25% (Sethi, T., et al. 2017).

Advancements in chemoradiation therapies have improved the long-term survival of patients of with CHL. Today, more than 85% of patients with early stage CHL will be cured of the disease (Ansell, S., et al. 2014). The 5-year overall survival for early stage CHL is 95% and for advanced disease is 82%. Overall, the prognosis of NSCHL is better than that of other types of CHL.

Initial studies examining the prognostic significance of grading of NSCHL based on cytological and tumor microenvironment features showed an association of higher grade (based on the British National Lymphoma Investigation (BNLI) criteria (Bennett et al. 1981; MacLennan et al. 1989)) with a poorer prognosis (MacLennan et al. 1989; Wijlhuizen et al. 1989; Ferry et al. 1993). However, since the advent of combination chemotherapy and the relatively good prognosis of NSCHL today, the significance of such grading or further classification has been called into question. Importantly, grading based on proposed histological features has declined in the last two decades because such advances in therapy can actually obscure the differences seen in less-effectively treated patients. As such, grading is not currently deemed necessary for routine clinical purposes.

Despite the broadly recognized clinical favorability of NSCHL, slowly accumulating evidence of poor clinical outcomes associated with the syncytial NSCHL histological variant is only now beginning to declare itself with strong evidence. While BNLI grading may no longer be a useful clinical tool, variant typing may instead prove effective as both a prognostic and alternative treatment indicator.

Small case studies have reported aggressive disease in SV NSCHL since the first histologic case was described. Clinical behavior has included presenting with a considerable mediastinal mass, significant B symptoms, and advanced stage at diagnosis. Despite these case reports, it was not until recently that systematic analysis of progression free survival and complete therapy response among morphology and immunophenotype SV confirmed cases in patients with similar treatment regimens (combination doxorubicin, bleomycin, vinblastine, and dacarbazine, or ABVD) was conducted (Sethi, T., et al. 2017).

Sethi, T., et al evaluated 167 patients with NSCHL: 43 patients with SV were compared with 124 patients with typical NSCHL on patient characteristics, disease variables, treatment administered, and outcome at Vanderbilt University Medical Center between 1995 and 2014. The rate of complete treatment response was lower in the SV variant as compared with typical NSCHL with standard induction therapy, 74% versus 87% (p= 0.05). Patients with SV had a shorter progression free survival and experienced disease relapse. The median progression free survival for the entire cohort was 174.7 months. The median progression free survival in the SV group was 17.02 months which was significantly shorter compared with that of the typical NS group, which was not reached (p < 0.0001).

The BNLI criteria for the grading of NSCHL (Grades I-II) are based on the amount of sclerosis, the degree of nodular cellularity, and the number of atypical neoplastic cells. Most SV cases are grade II because of the number of atypical cells present. However, most grade II cases are not syncytial variants. Therefore, BNLI grade alone is not an accurate depiction of the clinicopathologic features of this disease. In the same way, it may also not be the best determinant of disease prognosis, therapeutic indication, or investigative classification.

Patients with Syncytial Variant Nodular Sclerosis Classic Hodgkin Lymphoma experience a lower than expected rate of complete therapeutic response with shorter progression-free than non-SV NSCHL treated with standard therapy. Syncytial Variant NSCHL should therefore be recognized as a high-risk subgroup within the otherwise traditionally docile NSCHL classification. It is time the SV finally be considered a true histopathologic variant in future trials involving novel agents to assess treatment response. While a majority of patients with SV NSCHL can likely be successfully salvaged with high-dose therapy and autologous stem cell transplantation, studies of novel agents such as conjugated antibodies or immunotherapeutic agents should be considered in these patients to improve complete response rates and to avoid the need for toxic salvage therapies.

References

  1. Sethi T., et al. Differences in outcome of patients with syncytial variant Hodgkin lymphoma compared with typical nodular sclerosis Hodgkin lymphoma. (2017) Ther. Adv. Hematol. 8(1):13-20.
  2. Granot, N., et al. Syncytial variant of nodular sclerosing Hodgkin lymphoma in children: A prognostic factor? (2018) J. Ped. Hem. & Onc. 35;1:33-36.
  3. Ansell, S. (2014) Hodgkin lymphoma: 2014 update on diagnosis, risk stratification, and management. Am J Hematol 89: 771–779.
  4. Bennett, M., Maclennan, K., Easterling, M., Vaughan Hudson, B., Jelliffe, A. and Vaughan Hudson, G. (1983) The prognostic significance of cellular subtypes in nodular sclerosing Hodgkin’s disease: an analysis of 271 non-laparotomised cases (BNLI report no. 22). Clin Radiol 34: 497–501.
  5. Ben-Yehuda-Salz, D., Ben-Yehuda, A., Polliack, A., Ron, N. and Okon, E. (1990) Syncytial variant of nodular sclerosing Hodgkin’s disease. A new clinicopathologic entity. Cancer 65: 1167–1172.
  6. Ferry, J., Linggood, R., Convery, K., Efird, J., Eliseo, R. and Harris, N. (1993) Hodgkin disease, nodular sclerosis type. Implications of histologic subclassification. Cancer 71: 457–463.
  7. Maclennan, K., Bennett, M., Tu, A., Hudson, B., Easterling, M., Hudson, G. et al. (1989) Relationship of histopathologic features to survival and relapse in nodular sclerosing Hodgkin’s disease. A study of 1659 patients. Cancer 64: 1686–1693.
  8. Wijlhuizen, T., Vrints, L., Jairam, R., Breed, W., Wijnen, J., Bosch, L. et al. (1989) Grades of nodular sclerosis (NSI-NSII) in Hodgkin’s disease. Are they of independent prognostic value? Cancer 63: 1150–1153.
  9. Strickler, J., Michie, S., Warnke, R. and Dorfman, R. (1986) The “syncytial variant” of nodular sclerosing Hodgkin’s disease. Am J Surg Pathol 10: 470–477.
  10. Van Spronsen, D., Vrints, L., Hofstra, G., Crommelin, M., Coebergh, J. and Breed, W. (1997) Disappearance of prognostic significance of histopathological grading of nodular sclerosing Hodgkin’s disease for unselected patients, 1972–92. Br J Haematol 96: 322–327.
  11. Hess, J., Bodis, S., Pinkus, G., Silver, B. and Mauch, P. (1994) Histopathologic grading of nodular sclerosis Hodgkin’s disease. Lack of prognostic significance in 254 surgically staged patients. Cancer 74: 708–714.
  12. Darabi, K., Tester, W., Daskal, I. and Cohn, J. (2015) Syncytial variant of nodular sclerosing Hodgkin’s disease. Blood 104: 4533–4533.

Austin Headshot

-Austin McHenry is an M3 at Loyola University Stritch School of Medicine in Maywood, IL. Austin is past-president of the pathology intrest group SCOPE (Students Curious about Outrageous Pathology Experiences) and is a recent recipient of ASCP’s Academic Excellence and Achievement in Pathology Award. Follow Austin on Twitter @AustinMcHenry

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.

Ebola 2018

Approximately two years after Liberia, the hardest hit and last of the 6 countries to be affected in the largest Ebola outbreak since discovery of the disease in 1976, was declared Ebola-free, the virus has again reared its head. This time, its in the Democratic Republic of the Congo (DRC).

Timeline of the Outbreak:

  • May 3, 2018: a district in the Province of Equateur, DRC, reported 21 cases of undiagnosed illness with 17 deaths. Samples from 5 of these cases were sent to the Institute National Recherche Biomedicale in Kinshasa.
  • May 7: Ebola virus was confirmed by RT-PCR.
  • May 8, 2018: Ebola outbreak declared.
  • May 21: 628 contacts of confirmed or suspected cases listed.
  • May 25: 58 cases and 27 deaths.
  • June 1: the outbreak is contained in the Province of Equateur. This Province covers an area of 130442 km2 and has a population of 2,543,936. Equateur as 16 health zones and 284 health centers – this works out as 1 health center for every 9,000 people! The WHO warns that this outbreak has the potential to expand, and while at the moment there is no international spread, the Congo’s neighbors have been placed on alert. The WHO has distributed personal protective equipment, infrared thermometers, and rapid diagnostic tests to health centers in Equateur as well as neighboring countries.

The WHO considers laboratory diagnostics on of the pillars of the Ebola response. They recommend “strengthening diagnostic capabilities” as part of a strategic approach to the prevention, detection, and control of Ebola. In fact, laboratory diagnostics might be a key to how this epidemic plays out, versus the previous outbreak in West Africa wherein six African countries were affected and over 11,000 patients died. This time, there are rapid tests tests available ranging from lateral flow to molecular.

As part of the DRC’s National Laboratory Strategy developed in response to the outbreak, the GeneXpert confirmatory Ebola PCR test is being used a key sites in mobile laboratories. As of June 1, the WHO has deployed four mobile labs through out Equateur including the epicenter of the outbreak. Government Health Centers are equipped with rapid lateral flow tests: the ReEBOV Antigen Rapid Test released under Emergency Use Approval in 2015. According to WHO documents, this test has a sensitivity of 91% and specificity of 84.6%. Both positives and negatives should be confirmed with RT-PCR. The following is the guidance for the use of rapid tests:

Special settings where rapid antigen for Ebola may be beneficial:

  1. In the investigation of suspected Ebola outbreaks in remote settings where PCR tests are not immediately available. While awaiting confirmatory testing, action can be taken to: a) isolate test-positive patients, b) repeat daily testing on patients who initially tested negative but remain symptomatic, c) mobilize transport of samples for confirmatory testing and initiate outbreak-management procedures.
  2. In settings where the number of cases and suspects arriving for triage and care cannot be managed with the existing health staff and laboratory facilities.

Example situations where rapid antigen detection tests should NOT be used:

  • Individual case management – including for establishing definitive diagnosis or making therapeutic decisisions
  • Certification of Ebola virus-free status prior to medical care for other illnesses
  • Release of Ebola patients from Ebola Treatment Centers
  • Pooled blood samples for community-based testing
  • Testing blood before transfusion
  • Active case finding without confirmatory PCR
  • Any setting where action (quarantine, referral, care) based on results is not possible
  • Airport screening

So to summarize, currently in the Province of Equateur, suspected cases are tested by rapid test for initial triage, then samples are sent to the nearest lab for confirmation (positive or negative) by PCR. A suspected case cannot be released until there is a negative test by PCR. Suspected cases that initially negative by the rapid test are isolated from cases that are initially positive.

What about outside Equateur? I talked to Dr. Tim Rice, a friend and colleague serving as a missionary physician in Vanga, Congo. Vanga is the in Province of Bandundu, the northern neighbor of Equateur. While this province has not had a reported case of Ebola, they are getting ready. I asked him about their readiness plan and any laboratory capabilities they had. They have a rapid test: Ebola rapid lateral flow test from STADA Diagnostik (Germany). This assay detects the Ebola virus antigen VP 40 with a sensitivity of 92% and specificity of 98% (according to the package insert). Serum and throat swabs are acceptable specimens, although it is not clear which matrix was used to determine the performance characteristics. The package insert states that the performance characteristics are still being evaluated. Dr. Rice said they use the rapid test with patients with potential exposure and severely ill with fever.  Someone arriving from the Equatorial province with a fever, even if not severely ill, would be tested and isolated. They are to call the local health department for help in obtaining the correct confirmatory samples, properly storing the sample, alerting the regional and national leaders, and transporting the sample properly protected the 10 hours overland to Kinshasa for confirmatory PCR testing at the Institute National Recherche Biomedicale.

The response to the 2018 Ebola outbreak has been impressive and I sincerely hope that with the benefits of laboratory diagnostics and a vaccine, the world will be spared the devastation experienced in the previous outbreak.

 

Sarah Brown Headshot_small

–Sarah Riley, PhD, DABCC, is an Assistant Professor of Pediatrics and Pathology and Immunology at Washington University in St. Louis School of Medicine. She is passionate about bringing the lab out of the basement and into the forefront of global health.  

Microbiology Case Study: A 28 Year Old Female with Perirectal Abscess

Case History

A 28 year old female with a history of Ulcerative Colitis on humira and azathioprine presented with proctitis and a recent perirectal abscess. The patient reported a two week history of progressively worsening pain and swelling in the perianal region. In addition, she reported recent purulence excreted with bowel movements.  On physical exam, the patient was afebrile and negative for rash, oral lesions, joint pain, or abdominal pain. A perirectal abscess was identified and drained. Abscess culture was positive. Patient reported recently engaging in high-risk sexual behavior with multiple male sexual partners often without protection.

Lab Identification

neissgono
Image 1. Kidney-bean shaped gram negative cocci identified on Gram staining of perirectal abscess culture (100x oil immersion).  
neissgono2.png
Image 2. Aerobic growth of flat, gray-white, and moist colonies from perirectal abscess on chocolate agar plate.  

Abscess culture grew kidney-bean shaped gram negative diplococci. Colonies on chocolate agar plate appeared medium sized, flat, gray-brown, and moist. The organism was oxidase positive and identified by MALDI to be Neisseria gonorrhoeae.

Discussion

Neisseria gonorrhoeae is a kidney-bean shaped gram negative diplococci for which humans are the only host. The organism causes gonorrhea, a common sexually transmitted disease, among young people between the ages of 15-24 years. Gonorrhea is spread by sexual contact or through the birth canal. The most common site of infection is the urogenital tract.2 Males commonly present with dysuria with penile discharge.2 Females commonly present asymptomatically or with symptoms such as mild vaginal mucopurulent discharge and severe pelvic pain2. In addition, gonorrhea can cause infections of the anus, conjunctiva, pharynx, ovary and uterus.2 In the neonate, the culprit organism can lead to ophthalmia neonatorum.2 Lastly, gonorrhea causes disseminated disease such as arthritis, endocarditis, meningitis, and skin lesions on extremities.2 CDC currently recommends treating gonorrhea with dual therapy, a single dose of 250 mg intramuscular ceftriaxone and 1g of oral azithromycin.1

Antibiotic resistance in gonorrhea is an increasing public health concern. The World Health Organization has a program that monitors the global antimicrobial resistance of gonorrhea.3 The data from 77 countries between 2009 and 2014 showed that 66% of reporting countries had encountered gonorrhea strains with either resistance or reduced susceptibility to ceftriaxone.3 81% of reporting countries had encountered gonorrhea strains resistant to azithromycin.3 Given these data, it is important to improve gonorrhea prevention and continue to monitor gonorrhea antibiotic resistance at both the national and global levels.

References

  1. Gonorrhea treatment and care. (2017, Oct 31st). Retrieved on March 1st, 2018 from https://www.cdc.gov/std/gonorrhea/treatment.htm
  2. Miller KE. Diagnosis and Treatment of Neisseria gonorrhoeae Am Fam Physician. 2006 May 15:73 (10): 1779-1784.
  3. Wi T, et al. Antimicrobial resistance in Neisseria gonororheae: Global surveillance and a call for international collaborative action. PLoS Med 14(7): e1002344.https://doi.org/10.1371/journal.pmed.1002344

 

-Ting Chen, MD is a 1st year anatomic and clinical pathology resident at the University of Vermont Medical Center.

Wojewoda-small

-Christi Wojewoda, MD, is the Director of Clinical Microbiology at the University of Vermont Medical Center and an Associate Professor at the University of Vermont.