gamma/delta peripheral T-cell lymphoma of the breast diagnosed by fine-needle aspiration biopsy.

Gamma/delta T-cell lymphoma is a rare neoplasm that is not well characterized and is associated with a poor prognosis. We report a case of gamma/delta peripheral T-cell lymphoma that appeared as a breast lump in a 35-yr-old woman. The patient was examined for a 2-mo history of a right-sided breast mass with associated hepatosplenomegaly 2 yr in duration. A fine-needle aspiration biopsy (FNAB) was performed, and the diagnosis of lymphoma was rendered. The patient received two cycles of CHOP and is alive with persistent disease. FNAB showed evidence of polymorphous lymphoma, consisting of medium-size to large cells with immature chromatin. Flow cytometric immunophenotyping showed expression of CD2, CD3, and CD7 with lack of expression of CD1a, CD4, CD5, CD8, and CD56. Flow cytometry also showed predominant expression of the gamma/delta T-cell receptor. Cytogenetic analysis showed 48XX+i7(q11.2),+7(3). Our case indicates that gamma/delta peripheral T-cell lymphoma can be diagnosed by FNAB. This rare entity requires further investigation.