Mycosis fungoides(MF) is a cutaneous T-cell lymphoma of low-grade malignancy characterized by the proliferation of small to medium-sized cerebriform lymphoid cells confined to the skin. It usually shows favorable prognosis, but morphologic transformat...
Mycosis fungoides(MF) is a cutaneous T-cell lymphoma of low-grade malignancy characterized by the proliferation of small to medium-sized cerebriform lymphoid cells confined to the skin. It usually shows favorable prognosis, but morphologic transformation occurs in some cases and is often associated with a more aggressive clinical course. Herein we report a case of Ki-1 positive large cell lyrnphoma (Ki-1 LCL) which developed in the plaque stage of mycosis fungoides. Although the lesions responded well to low-dose methotrexate therapy and there was no evidence of local or systemic recurrence until now, continuous follow-up is needed because the prognosis of transformed MF is known to be poor compared with primary cutaneous Ki-1 LCL. We also discussed the differential diagnosis of primary cutaneous Ki-1 positive lymphoproliferative disorders. (Korean J Dermatol 1999;37(5) : 641-645)