Anaplastic large cell lymphoma--a rare disorder in southern Taiwan.

Anaplastic large cell lymphoma (ALCL) is a subgroup of non-Hodgkin's lymphomas with large lymphoma cells expressing CD30 antigen. This entity has rarely been reported in Taiwan. We performed a retrospective clinicopathologic study in a medical center in southern Taiwan during a 13-year period and identified 13 cases. There were 10 males and 3 females with a median age of 49 years old. Seven presented with pure nodal disease and 5 had bony involvement. The staging results were stage I (5 patients), II (1), III (1), and IV (4). The pathologic subtypes were common variant (10), lymphohistiocytic variant (2), and small cell variant (1). Eleven tumors were of T-cell lineage; 2, null-cell. Immunohistochemically, 5 tumors (38.5%) expressed cytotoxic markers, T-cell intracellular antigen-1 and/or granzyme B. Two tumors (15.4%) expressed anaplastic lymphoma kinase (ALK). Long-term follow-up information was available in 8 patients. The 2 patients with ALK-expressing tumors (37 and 49 years old) were free of disease for 61 and 54 months, respectively. The other 6 patients were either died of disease (5 patients) or experienced relapse with progressive disease (1). In conclusion, we reported the largest series of ALCL in Taiwan. We confirmed ALK-expressing ALCL carries favorable prognosis and ALK-negative ALCL has similar poor prognosis as non-anaplastic T-cell lymphoma. As compared to the previous reports from the West, our ALK positive rate was lower and the age of our ALK-positive patients was older. A larger national or multi-institutional study is needed for further characterization of ALCL in Taiwan.