CD4/CD8 double-negative early-stage mycosis fungoides associated with primary cutaneous follicular center lymphoma


    An 84-year-old man presented with an enlarged 2x2 cm nodule on the left posterior scalp that was found several weeks earlier. The nodule grew rapidly over the course of a few weeks. Recently, another skin nodule measuring 1x1 cm developed on the scalp. Physical examination also revealed multiple erythematous scaly patches with vague annular bor- ders on both anterior thighs and trunk, which had been cleared by topical steroids but recurred. The patient has no previous history of lymphoma and was largely asymptomatic. A comprehensive clinical stag- ing demonstrated skin-limited disease.

    The skin biopsy specimen from the left thigh demonstrated a classic patch lesion of MF. There was a diffuse atypical lymphocytic infiltrate primarily affecting the full thickness of the epidermis and dermoepidermal junction. Atypical lym- phocytes were CD31 bF11 T cells, which were negative for CD4 (<10% positive), CD8, TIA1, CD56, and CD20. Mild loss of CD7 expression was noted. The scalp lesion showed a cutaneous follicular center lymphoma by showing a pan-dermic infiltrate with follicular pattern com- posed of mixed population of small and large lymphocytes with a predominance of large centro- blasts. The neoplastic cells were positive for CD20, BCL6 and CD10 (weak) and were negative for CD3, CD4, CD8, BCL2, and MUM-1. The negativity for BCL2 supports a cutaneous origin for this neoplasm.