Anaplastic large cell lymphoma: A great mimic on cytology

Pitfalls in Lymph Node Fine Needle Aspiration Cytology

BACKGROUND

Fine needle aspiration cytology (FNAC) is an accurate, minimally invasive, and cost-effective biopsy method for enlarged lymph nodes. While the role of lymph node FNAC in the diagnosis of infectious or reactive conditions and metastatic malignancy is unquestioned, differing views still exist on its role in the diagnosis of lymphoma. Nevertheless, regardless of the practice setting, pitfalls and potential for error exist, and it is incumbent upon the pathologist to be aware of these pitfalls, as this is the first line of defence against errors.

SUMMARY

This discussion will focus on potential interpretational errors, specifically highlighting scenarios leading to false-negative and false-positive diagnosis and errors in tumour classification, with an emphasis on cytomorphology. Potential entities that may fly below the radar of the pathologist - so-called off-radar entities - are also discussed, as a reminder to consider broad differentials in cases with unusual morphologic features. Some reasons for false-negative diagnoses include low-grade lymphomas that mimic a mixed, polymorphous reactive lymphoid population or aspirates with a paucity of lesional cells, through either sampling error or the intrinsic nature of the entity, e.g., nodular lymphocyte predominant Hodgkin lymphoma. Some of the potential causes of false-positive diagnoses that are discussed include viral-associated lymphadenopathy, Kikuchi-Fujimoto lymphadenitis, or benign adnexal lesions mimicking metastatic malignancy. Errors in tumour classification covered include metastatic carcinoma, sarcoma, melanoma, and lymphoma mimicking each other, and Hodgkin lymphoma and its mimics. Finally, less common entities such as follicular dendritic cell sarcoma and others are briefly mentioned, to remind us of conditions that may slip under our diagnostic radar.

KEY MESSAGES

A systematic review of diagnostic pitfalls and traps is elucidated here, with some tips to avoid these traps. The triple approach to the diagnostic workup is emphasised, which includes rigorous clinicopathologic correlation, attention to cytomorphology, and judicious application of ancillary tests.

Rare Presentation of Hypoglycemia in a Patient with Anaplastic Large-Cell Lymphoma

Anaplastic large-cell lymphoma is a rare type of aggressive non-Hodgkin's lymphoma, and arriving at a final diagnosis for this tumor is a challenge for the healthcare providers. Usually, it involves the lymph nodes and extranodal tissues such as the lungs, skin, and other soft tissues. Its presentation by extending into different organs such as the liver, lungs, bones, spleen, and thyroid is rare. Thus, involvement of other organs is very rare as we found in a 54-year-old male patient, a known case of hypertension and end-stage renal disease who was on hemodialysis, who presented to the emergency department with a history of generalized weakness and weight loss of about 20 kg for two months. The tumor cells are positive for CD45, CD30, CD15, MUMi, and Ki-67 (80%) and negative for CD20, PAX-5, CD79a, CD3, CD5, CD10, BCL6, BCL2, EMA, ALK-1, and CD138. The patient was hypoglycemic and hypercalcemic and was managed accordingly. The patient was evaluated, and the third assessment showed that hypoglycemia was resolved due to dexamethasone. The patient's glucose storage was depleted most likely due to liver involvement plus poor general condition. It was asserted that the patient's hypoglycemia could be related to his underlying malignancy. Also, the patient was advised to start tablet diazoxide 45 mg three times a day (3 mg/kg/day TID) in addition to levothyroxine tablet 50 mcg once a day. Tablet diazoxide was stopped, and nutritional support was recommended. This case reveals a rare systematic ALK-1-negative anaplastic large-cell lymphoma that involves multiple organs. The main learning point from this report is that these tumors can present atypically even in adults and can be ALK-1 negative, which is contrary to the typical systematic anaplastic large-cell lymphomas that are positive for ALK.

The Utility of Ancillary Techniques in the Cyto-Diagnosis of Malignant Scalp Lesions

Background

Fine needle aspiration cytology (FNAC) is rapid, inexpensive, and easy technique to establish the diagnosis of scalp lesions. The use of ancillary techniques such as immunocytochemistry (ICC), immunohistochemistry (IHC), and flow cytometry on aspiration material aids in accurate diagnosis which is additionally beneficial for management and prognosis.

Aims

The objective of this prospective case series was to evaluate the utility of ancillary techniques in the accurate cyto-diagnosis of malignant scalp lesions.

Materials and Methods

This study was a prospective case series that included 64 cases of scalp lesions in which FNAC had been performed for diagnosis. The lesions were categorized as Non-diagnostic/Inadequate, Inflammatory, Benign and Malignant. In all the cases that were categorized as malignant additional material was collected for ancillary testing that included ICC, cell block preparation followed by IHC and flow cytometry.

Results

Non-diagnostic/inadequate aspirates were 17.19% (n = 11/64), 25% (n = 16/64) aspirates were inflammatory, 35.93% (n = 23/64) aspirates were benign and 21.87% (n = 14/64) aspirates were categorized as malignant. With the aid of ancillary techniques, 57.14% malignant scalp aspirates were accurately categorized as epithelial origin. Lesions of bone and soft tissue constituted 28.57% (n = 4/14) of cases and lesions of hematolymphoid origin constituted 14.29% (n = 2/14) of all cases.

Conclusion

This is a novel study where accurate categorization of malignant scalp tumors has been done with the use of ancillary techniques. This is useful as it may help in defining the tumor type, may aid in patient management. The material obtained can also be triaged for molecular testing.

Cytoskeleton Dynamics in Peripheral T Cell Lymphomas: An Intricate Network Sustaining Lymphomagenesis

Defects in cytoskeleton functions support tumorigenesis fostering an aberrant proliferation and promoting inappropriate migratory and invasive features. The link between cytoskeleton and tumor features has been extensively investigated in solid tumors. However, the emerging genetic and molecular landscape of peripheral T cell lymphomas (PTCL) has unveiled several alterations targeting structure and function of the cytoskeleton, highlighting its role in cell shape changes and the aberrant cell division of malignant T cells. In this review, we summarize the most recent evidence about the role of cytoskeleton in PTCLs development and progression. We also discuss how aberrant signaling pathways, like JAK/STAT3, NPM-ALK, RhoGTPase, and Aurora Kinase, can contribute to lymphomagenesis by modifying the structure and the signaling properties of cytoskeleton.

Binucleate Cells in Cytosmears: What do They Signify?

Background

Although the classic Reed-Sternberg (RS) cell is considered a diagnostic of Hodgkin's disease, RS-like cells have been noted in various benign and malignant conditions. The presence of these cells can be a diagnostic challenge.

Aims

Our aim was to see if cells morphologically resembling or identical to RS cells occur in conditions other than Hodgkin lymphoma (HL) and what proportion of cases show binucleate cells in various benign and malignant conditions. We also want to discuss the diagnostic utility of cytomorphological features in predicting HL.

Material and Methods

This study is a retrospective analysis of 2086 cytology cases. The cytosmears were screened for the presence of binucleate cells. A detailed cytomorphological analysis of cytosmears with binucleate cells was performed, and the diagnostic utility of cytomorphological criteria in delineating HL was examined.

Results

Out of 2086 smears, 55 (2.6%) cytosmears showed binucleated RS/RS-like cells. Out of these 55 cases, 6 were HL, 3 cases were non-HL (NHL), 3 were sarcoma, 32 were carcinoma, and 11 were benign/inflammatory lesions. The presence of prominent eosinophilic nucleoli, granulomas, and eosinophils had good sensitivity and specificity in predicting the diagnosis of HL.

Conclusion

A detailed cytomorphological analysis is of limited value in categorizing the RS and RS-like cells. However, few cytomorphological features such as prominent eosinophilic nucleoli, eosinophils, granulomas, and lack of clustering of atypical cells can help us in predicting HL.

Anaplastic large cell lymphoma: Report of two cases with rare patterns (carcinomatous and sarcomatous) in fine needle aspiration cytology and histopathology

Anaplastic large cell lymphoma (ALCL) is a non-Hodgkin lymphoma of T-cell or null-cell lineage with variable cytomorphology. We report two rare ALCL cases with carcinomatous and sarcomatous patterns, respectively, in fine needle aspiration (FNA) cytology and histopathology. The first case was a 56-year-old man with enlarged left inguinal lymph node. FNA smears showed a malignant small round cell tumor with nuclear molding. In addition, there were large bi-nucleated and multinucleated cells with wreath-like arrangement of nuclei. ALCL and small cell (neuroendocrine) carcinoma were the possibilities considered. Immunocytochemical studies on FNA smears showed positive reaction for leukocyte common antigen (LCA) and negative results for cytokeratin (CK) and chromogranin. Histopathological examination of the lymph node showed features of ALCL with following immunohistochemical staining results: LCA+, CD30+, CD45RO+, CD20-, CD3+ (weak), and Alk1-. During review of sections, areas resembling a small cell anaplastic carcinoma were observed. The second case was a 24-year-old woman with right cervical lymphadenopathy. FNA smears showed an ALCL with highly atypical large cells including bi-nucleated and donut shaped cells, which were positive for CD30, EMA, and Alk-1 protein, and negative for CD20, CD3, and CK. Histopathological examination corroborated the cytodiagnosis of ALCL, and with positive immunohistochemical staining for CD30, EMA, Alk-1 protein+, BCL6+, and Ki67+ (40% cells) and negative results for CD20, CD10, CD3, CD5, CD15, BCl2, CD79a, and CD68. Sarcomatous components were noticed during review of cytologic and histopathological specimen. Awareness about these unusual cytomorphological patterns in ALCL may be of help in proper diagnosis of this neoplasm.

A Proposal for the Performance, Classification, and Reporting of Lymph Node Fine-Needle Aspiration Cytopathology: The Sydney System

BACKGROUND

The evaluation of lymph nodes (LN) by fine-needle aspiration cytology (FNAC) is routinely used in many institutions but it is not uniformly accepted mainly because of the lack of guidelines and a cytopathological diagnostic classification. A committee of cytopathologists has developed a system of performance, classification, and reporting for LN-FNAC.

METHODS

The committee members prepared a document that has circulated among them five times; the final text has been approved by all the participants. It is based on a review of the international literature and on the expertise of the members. The system integrates clinical and imaging data with cytopathological features and ancillary techniques. The project has received the endorsement and patronage of the International Academy of Cytology and the European Federation of the Cytology Societies.

RESULTS

Clinical, imaging, and serological data of lymphadenopathies, indications for LN-FNAC, technical procedures, and ancillary techniques are evaluated with specific recommendations. The reporting system includes two diagnostic levels. The first should provide basic diagnostic information and includes five categories: inadequate/insufficient, benign, atypical lymphoid cells of undetermined/uncertain significance, suspicious, and malignant. For each category, specific recommendations are provided. The second diagnostic level, when achievable, should produce the identification of specific benign or malignant entities and additional information by utilizing ancillary testing.

CONCLUSION

The authors believe that the introduction of this system for performing and reporting LN-FNAC may improve the quality of the procedure, the report, and the communication between cytopathologists and the clinicians. This system may lead to a greater acceptance and utilization of LN-FNAC and to a better interdisciplinary understanding of the results of this procedure.

Violet - Colored Inguinal Located Cutaneous Tumour?

Anaplastic large cell lymphoma (ALCL) represents an aggressive CD30 – positive T cell lymphoma, as it is the second most common T cell lymphoma and 2% to 5% of all non - Hodgkin lymphomas. The cutaneous involvement can be primary or secondary within systemic ALCL, resembling inflammatory and other neoplastic lesions both clinically and cytologically. Various pigmented cutaneous tumours with a different origin, cutaneous metastasis and B-cell lymphoma must be carefully considered in the differential diagnostic plan. While simple surgical excision is usually curative, with good prognosis, systemic involvement must also be excluded. We present a case of a patient, with clinically unspecific single violet nodular lesion, as the only clinical manifestation of ALCL. The diagnosis was confirmed histologically, as the surgical excision was enough therapeutic management, regarding the early disease stage. Further following up with the patient is mandatory, because of the high recurrence rate. We want to emphasise the diversity of clinical manifestation of ALCL, regarding the importance of its early diagnosis and treatment.