Localized peritoneal epithelioid clear cell subtype mesothelioma: a case report and literature review

Epithelioid mesothelioma with a clear cell morphology is rare and has only been described in a few case reports. The diagnosis of epithelioid clear cell mesothelioma is challenging and often requires extensive immunohistochemical staining. Here, we report a case of epithelioid mesothelioma, clear cell variant, occurring in the peritoneum of a 76-year-old male. Computed Tomography(CT)imaging revealed a localized irregular intra-abdominal mass measuring approximately 6.0×5.0cm. Combined with histomorphology and immunophenotype analysis, the patient was diagnosed with localized epithelioid clear cell mesothelioma. There was no recurrence or metastasis after 24 months of follow-up. This case enriches the clinical and molecular data of localized peritoneal epithelioid clear cell mesothelioma, and provides insights into its diagnosis, differential diagnosis, and treatment.