Familial mycosis fungoides.

Abstract

Sir, Mycosis fungoides (MF) is a malignancy of CD4+ helper T lymphocytes, which primarily affects the skin and may later involve visceral organs. It is mainly a disease of the elderly and has only rarely been described in childhood.1 The aetiopathogenesis of MF is not well understood and its genetic basis has not been proved. To the best of our knowledge, there are only six cases of familial MF in the literature.2–5 We report a 37‐year‐old mother and her 5‐year‐old son, both of whom had MF. A 37‐year‐old woman had had plaque‐stage MF for 12 years. Psoralen plus ultraviolet (UV) A (PUVA) therapy was applied with success, although recurrence was observed. No tumours or extracutaneous involvement were recorded in 3 years of follow‐up. Her son was admitted to our clinic at 5 years of age with asymptomatic, slightly erythematous non‐infiltrated plaques with fine scales on the proximal extremities, buttocks and trunk (Fig. 1a). Mycological examination of the skin lesions was negative. He had no atopic diathesis and total IgE was normal. Other laboratory findings were normal. New lesions appeared and old ones showed no regression under treatment with topical corticosteroids and urea‐containing ointments. Skin biopsy of three plaques revealed the same findings: focal parakeratosis with mild epidermal acanthosis; a few intraepidermal lymphocytes usually seen as single cells and rarely as small collections of a few cells reminiscent of Pautrier abscesses; and mild fibrosis and perivascular lymphocytic infiltration in the papillary dermis (Fig. 1b). The histopathological picture was reminiscent of early MF. A T‐cell receptor gene rearrangement study could not be performed. Carmustine 10 mg was applied daily to the entire skin for 2 months and the lesions regressed completely. However, a recurrence characterized by a few plaques was observed during a 6‐month follow‐up period. The same topical treatment was applied to the new lesions.