Pityriasis rotunda. A cutaneous sign of malignant disease in two patients.

The term pityriasis rotunda refers to strikingly circular scaly lesions, with the histologic appearance of ichthyosis vulgaris. Pityriasis rotunda has been described in the Japanese, South African blacks, and West Indian blacks. The condition occurs only in association with certain serious systemic illnesses, usually tuberculosis, or malignant neoplasms or less severe diseases of the female genital tract (eg, fibroids, ovarian cyst). We describe two South African blacks with pityriasis rotunda and neoplasms. The cutaneous lesions cleared when the primary neoplasm was treated.