Unravelling the Diagnosis - The Role of Histopathology in Mycosis Fungoides.

Mycosis fungoides is an extra-nodal indolent non-Hodgkin lymphoma of T- cell origin that is characterized by skin involvement. The course of the disease is typically slowly progressive with non-specific clinical and histopathologic features which may evade diagnosis for years. Chemo-therapeutic agents to control the disease are effective if employed early, but the prognosis and therapy is dependent on the stage of the disease at presentation. We report a case of a 25-year old man with a clinical diagnosis of Tinea incognito and histologic features of non-specific dermatitis at first presentation. With poor hospital attendance and inconsistent therapy, his clinical features and histology reports over the next couple of years were consistent with psoriasis, then mycosis fungoides. He is currently stable on chemotherapeutic agents. With different histopathology results over a three- year span, it is possible that the patient had both diseases occurring separately. It is also possible that psoriasis was a harbinger of mycosis fungoides and the change in clinical presentation which necessitated repeated biopsies eventually revealed the picture.