BACKGROUND
Epstein-Barr virus (EBV)-associated smooth muscle tumor (EBV-SMT) is a recently characterized histopathologic diagnosis. EBV-SMTs are rare mesenchymal tumors comprising EBV-infected smooth muscle cells that usually follow an indolent course, may be multifocal, occur in immunocompromised individuals, and can present with nonspecific symptoms. Diagnosis requires histopathologic examination, immunohistochemistry for smooth muscle cell markers, and in situ hybridization for Epstein-Barr virus-encoded RNA (EBER-ISH). This report describes a human immunodeficiency virus (HIV)-positive individual with hepatic EBV-SMT and suspected multifocal disease.
CASE REPORT
Beginning at age 47, a Thai man with HIV infection developed multiple leiomyomatous lesions over 2 decades, including tumors involving the tonsil, central nervous system, and spine. In 2023, computed tomography demonstrated masses in the liver, adrenal glands, and small intestine. Because of progressive abdominal pain and mass effect, left hepatectomy was performed. Histopathologic examination of the hepatic lesion revealed a well-circumscribed spindle cell tumor arranged in interlacing fascicles without significant atypia or mitotic activity. Immunohistochemically, tumor cells showed smooth muscle actin positivity and desmin/CD117 (KIT) negativity. EBER-ISH demonstrated positive nuclear staining in hepatic tumor cells, confirming the diagnosis of EBV-SMT. Additional extrahepatic lesions were clinically suspected to represent EBV-SMT but were not pathologically confirmed as EBV-associated in this report.
CONCLUSIONS
This case documents a prolonged course of apparently multifocal smooth muscle tumors in an HIV-infected patient, culminating in an EBER-ISH-confirmed hepatic EBV-SMT; additional lesions remain clinically suspected without pathologic confirmation of EBV association. This case suggests that EBV-SMT should be considered and confirmed by EBER-ISH when smooth muscle tumors arise at unusual anatomic sites in immunocompromised patients.

Keywords: HIV; Leiomyomatosis; Liver Diseases; Tumor Virus Infections; Virus Diseases