Lipoatrophia semicircularis: a compressive lipoatrophy consecutive to persistent mechanical pressure.

Lipoatrophia semicircularis is an infrequent condition characterized by semicircular depressions of the anterolateral aspects of the thighs. The origin of this peculiar variant of lipoatrophy is unknown, although repeated mechanical trauma on the affected thighs has been advocated in many cases. A 57-year-old woman presented with a 1-year history of two bilateral, parallel, symmetric, asymptomatic depressions on the anterolateral aspect of her thighs. The patient worked as a cashier, permanently seated and almost always wearing trousers. The localization of lesions and their linear artifactual appearance perfectly matched with the strangling folds formed by trousers while being sat. Echotomographic examination revealed a loss of the normal echogenic pattern in the subcutaneous tissue of the affected areas. We believe that the anatomical adipose constitution of women's thighs predisposes that a persistent mechanical pressure induced by wearing trousers while being sat for long periods of time, originates a relative impaired circulation on a tenuous perfused tissue, and induces the development of lipoatrophia semicircularis.