Gamma/delta T-cell lymphoma involving the subcutaneous tissue and associated with a hemophagocytic syndrome.

A case of gamma/delta-positive T-cell lymphoma localized primarily in the subcutaneous adipose tissue and associated with an extensive hemophagocytic syndrome and a rapid, fatal outcome is presented. Previous reports of gamma/delta cutaneous and subcutaneous T-cell lymphomas are reviewed. To define the characteristics of a T-cell subset of neoplastic cells bearing the gamma/delta receptor in a subcutaneous lymphoma, we undertook clinical and laboratory examinations, morphological evaluation of biopsies, electron microscopy, and extensive immunohistochemical studies. Immunohistochemical studies showed that the neoplastic cells expressed the gamma/delta T-cell receptor (CD3+, C gamma M1+) and were CD2+, CD43+, CD45+, CD45RO+, PCNA+, but were beta F1-, CD1-, CD4-, CD8-, CD15-, CD20-, CD25-, CD30-, CD45R-, CD57-, CD68-, Mac 387-, and HLA Dr-. To the best of our knowledge, this is the first report of a subcutaneous T-cell lymphoma of gamma/delta type involving the subcutaneous tissue and associated with a hemophagocytic syndrome.