Kaposi Sarcoma in an HIV-Negative Patient Following Temozolomide Chemoradiation Treatment for High-Grade Glioma.

Kaposi sarcoma is a rare vascular neoplasm caused by human herpesvirus 8 (HHV8), commonly associated with human immunodeficiency virus (HIV) infection or iatrogenic immunosuppression. This report describes the case of a 44-year-old male who recently completed chemoradiation therapy for a high-grade midline glioma who presented with a right upper eyelid lesion. Wedge resection of the lesion was performed. Microscopic examination revealed a nodular proliferation of atypical medium-sized spindled cells with numerous vascular spaces and scattered mitotic figures. Immunohistochemical staining confirmed that the atypical cells were positive for HHV8, supporting the diagnosis of Kaposi sarcoma. This case may represent an exceptionally rare example of Kaposi sarcoma in a patient with immunosuppression resulting from chemotherapy for a previously diagnosed brain tumor. This case may help inform future investigations into the molecular mechanisms of HHV8-induced cellular transformations that lead to the development of Kaposi sarcoma and may also inform future conversations on the risks and benefits of different chemotherapy regimens in high-grade glioma patients.