Blastoid Variant of Mantle Cell Lymphoma with Extranodal Presentation and Aberrant CD10 Expression.

Mantle cell lymphoma (MCL) constitutes 3%-10% of non-Hodgkin lymphoma and is characterized by t (11:14)(q13;q32). The common presentation is generalized lymphadenopathy with weight loss, infrequently night sweats, and fever. Among histological subtypes of MCL, the blastoid variant of MCL constitutes 10%-15% of all the cases. It is challenging to diagnose the blastoid variant of MCL based on its morphology alone as it mimics large B-cell lymphoma. Hence, the immunophenotyping and molecular studies aid in its correct diagnosis. We report an elderly man diagnosed with blastoid variant MCL. He presented with disseminated soft-tissue and subcutaneous nodules, and showed aberrant CD10 expression. Presentation of the extranodal site and aberrant CD10 expressions carries an overall poor prognosis. CD10-positive MCL can be mistaken for large B-cell lymphoma.