Diagnosis of anaplastic lymphoma kinase‐negative anaplastic large cell lymphoma on pleural fluid cytology

Abstract

ALK‐negative anaplastic large cell lymphoma (ALCL) is an aggressive non‐Hodgkin T‐cell lymphoma. Compared to ALK‐positive ALCL, patients with ALK‐negative ALCL typically are older, present with nodal disease, and have lower survival rates. We report a unique presentation of ALK‐negative ALCL in a pleural fluid. Cell block preparation enabled both confirmation of the diagnosis via immunohistochemical staining and gene rearrangement testing for prognostic information.

The Difficulties and Ease of Diagnosing Anaplastic Large Cell Lymphomas on Cytology

“…Infection with the Epstein-Barr virus occurs in a high percentage of patients with syncytial HL and the lymphocyte-depleted variant of HL, a finding that is not noted in ALCL. [ 1 32 ]…”

“…However, cell block preparations can enable both confirmations of the diagnosis via IHC staining and gene rearrangement testing for prognostic information, especially in highly cellular exfoliative cytology fluids. [ 1 ]…”

“…Anaplastic large cell lymphoma (ALCL), a unique non-Hodgkin T-cell lymphoma (NHL), is recognized under the group of large cell lymphoma with strong expression of CD30 positive pleomorphic cells. [ 1 2 3 4 5 ] Various molecular abnormalities have been detected in ALCL, such as t(2,5)(p23, q35), t(1;2)(q25;p23), t(2;3)(p23;q21), t(2;22)(p23;q11.2), and inv(2), which result in overexpression of anaplastic lymphoma kinase-1 (ALK-1) protein in immunohistochemistry (IHC). [ 5 6 ] Based on this ALK-1 protein expression and clinical data, it is broadly classified into two types, namely, systemic ALCL and primary cutaneous ALK-1 negative ALCL.…”

“…[ 5 6 ] Based on this ALK-1 protein expression and clinical data, it is broadly classified into two types, namely, systemic ALCL and primary cutaneous ALK-1 negative ALCL. [ 1 ] Systemic ALCL is subdivided into breast implant-associated ALCL, ALK-1 negative ALCL, and ALK-1 positive ALCL. [ 1 4 ] On the morphology, apart from the common pattern (70%) which is the most common, there are other variants namely lymphohistiocytic (10%), small cell (5–10%), Hodgkin’s like (3%), composite (15%), and rarely others like sarcomatous, giant cell-rich, and signet ring variant.…”