It is an uncommon form of lymphoma that initially manifests itself in the skin - considered an epidermotropic variant of a cutaneous T-cell lymphoma (CTCL) that accounts for 50% of primary cutaneous lymphomas.
Clinical features Mycosis Fungoides tends to affects 40-60 yr olds; male to female ratio = 2:1. Particularly affects covered sites eg breasts.
Mycosis Fungoides has 3 clinical stages : 1. Patch stage with erythematous macules on trunk and extremities 2. Plaque stage - elevated scaly pink/red/brown plaques, often pruritic 3. Tumour stage - dome-shaped firm tumours on face, scalp and body folds Density of lymphoid infiltrate increased through each stage. LN and visceral organ involvement occurs later.
Pathology Neoplastic cells are T-helper CD4 cells and memory T-cells. These form a band-like infiltrate in the upper dermis and infiltrate the epidermis -> aggregates called Pautrier's microabscesses.