[Pseudocyst of the scalp: two cases]

Pseudocysts of the scalp are a poorly known entity. Herein we present two new cases.

Two male patients aged respectively 42 and 33 years had been presenting a small number of pseudocystic lesions on the scalp, as well as alopecia limited to the same region, for a number of years. Inflammatory episodes had occurred in certain lesions. In one case, biopsy showed an aspect typical of pseudocyst of the scalp and the lesions appeared to stabilize on treatment with doxycycline.

Pseudocysts of the scalp are also known as aseptic nodules of the scalp, a term that appears to us to be less appropriate. They form lesions involving alopecia and they may be inflammatory to various degrees. Following incision of these lesions, a deep yellow fluid liquid is released that may be shown by microbiological analysis to be sterile. Histological analysis reveals a pseudocystic wall associated with perilesional inflammatory remodelling. The cysts are frequently confused with dissecting cellulitis of the scalp, but the prognosis is more encouraging. Treatment involves surgical excision, and intralesional injections of corticosteroids or doxycycline.