Thymic carcinoma in a child with HIV infection.

HIV infection predisposes to cancer during childhood. In addition to the AIDS-defining non-Hodgkin lymphoma (NHL) and Kaposi sarcoma, a range of other lymphoid malignancies and solid tumors have been described. We report the first case of an HIV-positive child with thymic carcinoma in the setting of regressing thymic cysts. The tumor expressed CKIT but failed to respond to imatinab mesylate after a transient response to multiagent chemotherapy. This case extends the spectrum of pediatric malignancy in the setting of HIV and suggests that patients with presumed benign thymic cysts require ongoing surveillance.