Epstein-Barr Virus-Positive Leiomyosarcoma in Immunocompetent Patients.

Area of Science:

• Oncology
• Virology
• Pathology

Background:

• Epstein-Barr Virus-Associated Smooth Muscle Tumors (EBV-SMT) are rare, often occurring in immunosuppressed individuals.
• Leiomyosarcomas (LMS) are malignant tumors arising from smooth muscle tissue.
• Investigating EBV presence in non-immunosuppressed LMS cases is crucial for understanding tumor heterogeneity.

Purpose of the Study:

• To evaluate ordinary leiomyosarcomas (LMS) for Epstein-Barr virus (EBV) presence.
• To describe the clinicopathological features of EBV-positive LMS in immunocompetent patients.
• To differentiate these findings from classical EBV-SMT.

Main Methods:

• Analysis of 93 classical LMS tissue microarrays using EBER in situ hybridization and LMP1 immunohistochemistry.
• EBV real-time PCR performed on EBER-positive cases.
• Clinicopathological features of identified EBV-positive LMS were documented.

Main Results:

• Two non-uterine LMS cases (2.2%) tested positive for EBER and negative for LMP1, designated as `EBV-positive LMS`.
• Both cases occurred in immunocompetent females in their 6th decade, with tumors in the pancreas and chest wall.
• Morphological features included myxoid stroma, multinodular growth, spindle cells with intermediate- to high-grade features, high mitotic activity, focal necrosis, and absence of lymphocytes. One patient developed metastatic disease.

Conclusions:

• EBV-positive LMS in immunocompetent patients present with distinct clinicopathological characteristics.
• These findings differentiate them from EBV-SMT typically observed in immunosuppressed individuals.
• Further research is warranted to elucidate the role of EBV in LMS pathogenesis in immunocompetent hosts.