ALK-negative primary cutaneous T-cell anaplastic large cell lymphoma, myxoid variant; masquerading as sarcoma: unveiling the diagnostic dilemma.

We present a case of 50-year-old man with history of ulcerative right axillary mass for 6 months. Axillary lymphadenopathy and organomegaly were absent. Microscopic examination showed sheets of pleomorphic cells which were mitotically active. Distinctive myxoid change was seen throughout the tumor. These cells were strongly positive for CD30 and vimentin but were negative for CD3, CD5, CD20, CD15, anaplastic lymphoma kinase protein (ALK), CD56, cytokeratin, melan A, desmin, myogenin, CD68, S100, epithelial membrane antigen and CD34. The final diagnosis of primary cutaneous ALK-negative T-cell anaplastic large cell lymphoma (PCALCL), myxoid variant was made. Work-up revealed no systemic involvement. The patient received eight cycles of cyclophosphamide, doxorubicin, vincristine, prednisone and etoposide chemotherapy with complete resolution of disease. This case report highlights that a high index of suspicion is necessary in patients of PCALCL due to varied clinical presentation, and to discuss in brief the histopathologic and immunophenotypic features of this entity along with its differential diagnosis.