Mycosis fungoides associated with intestinal mucosa-associated lymphoid tissue lymphoma.

Coexistence of cutaneous T-cell lymphoma (CTCL) and a B-cell malignancy is rare. We report a case of mycosis fungoides (MF) associated with intestinal mucosa-associated lymphoid tissue (MALT) lymphoma, which is a low-grade B-cell lymphoma of marginal cell origin. To the best of our knowledge, there have been only two cases of coexistent CTCL and MALT lymphoma, and this is the first case with typical MF and intestinal MALT lymphoma. The coexistence in our case might be coincidental, but genetic predisposition and the immunoregulatory capacity of neoplastic T lymphocytes may be factors contributing to this association.