Erythrodermic mycosis fungoides with large cell transformation: An unusual and complicated case.

Mycosis fungoides is the most common cutaneous T-cell lymphoma. It presents a diagnostic challenge due to resemblance with many other dermatologic conditions. The disease typically follows a progression from patches to plaques to skin-based tumors with potential for visceral involvement. Diagnosis is made by clinical presentation and histology. When early diagnosis is made, there is an estimated 88% five-year survival. This report details a 60-year-old Black man diagnosed with stage IIIA mycosis fungoides with a severe degree of cutaneous involvement. This case is unique due to the aggressive large cell transformation and rapid progression to death within 18 months of diagnosis. We highlight the challenge of diagnosing, treating, and monitoring the therapeutic response of mycosis fungoides. Finally, this case calls for a multi-disciplinary approach to treatment and to include mycosis fungoides on the differential diagnosis for patients presenting with a variety of vague, recurrent cutaneous symptoms, especially with patchy dyspigmentation or plaques.