Primary cutaneous mantle cell lymphoma with blastic features: report of a rare case with special reference to staging and effectiveness of chemotherapy.

We describe a case of blastic primary cutaneous mantle cell lymphoma (MCL) in an 83-year-old male with a complex medical history. The patient presented to his primary care physician with a nodular erythematous skin eruption on his thighs. Histopathologic examination showed a diffuse lymphoid infiltrate of intermediate to large cells that involved the dermis and subcutis but spared the epidermis. Immunohistochemical staining showed expression of CD20, CD5 and cyclin-D1. The lymphoma cells were negative for CD10 and CD23. Fluorescence in situ hybridization (FISH) analysis revealed a characteristic translocation [t(11;14)(q13;q32)], which is diagnostic of MCL. Cutaneous involvement by MCL is typically secondary because of widespread disease, and primary cutaneous MCL can only be diagnosed in the absence of extracutaneous involvement. Primary cutaneous MCL is extremely rare and requires proper clinical staging. In this case, clinical staging revealed no evidence of bone marrow or peripheral blood involvement, and positron emission tomography (PET) scan revealed weak, abnormal uptake only in a few cervical lymph nodes. Because of the lack of disseminated involvement, we favor the lesion to be a primary cutaneous MCL.