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.