[Inguinal pseudotumor: relapse of a pemphigus after 15 years' remission]

Pemphigus vegetans (PV) is a rare type of pemphigus vulgaris. We report a patient with pemphigus vulgaris relapsing as an isolated vegetative tumour.

A 59-year-old man was seen in February 2001 for a tumour on the right groin. He had received systemic corticosteroids and cyclophosphamide for pemphigus vulgaris from 1974 to 1985, and he had been in complete remission since 1985. At the time of evaluation, a 10 x 5 x 5 cm, smooth vegetative tumour was seen on the right groin. Biopsies showed spongiosis, acanthosis and some acantholysis. Direct immunofluorescence showed strong deposition of immunoglobulin G within the intercellular substance of the epidermis. Indirect immunofluorescence revealed anti-intercellular antibodies at a titer of 1/800. Immunoblot analysis showed reactivity with the 130 kD pemphigus vulgaris antigen. PVg was diagnosed. Local corticosteroid treatment was initiated. The patient was disease-free at follow-up three years later.

Localised forms of pemphigus are very rare. Twenty four other cases have been reported among them just one case of localised PV. Our case report is very unusual because of the variability of the expression of the disease, the high antibody level, the absence of trigger factors, and the efficacy of the local corticosteroid treatment.