Related Experiment Video
Updated: May 7, 2026
Orthotopic Implantation and Peripheral Immune Cell Monitoring in the II-45 Syngeneic Rat Mesothelioma Model
Published on: October 2, 2015
Localized Intrasplenic Mesothelioma: A Case Report
Michele Giansanti1, Guido Bellezza2, Angela Guerriero1
1Department of Experimental Medicine, Section of Pathology, Medical School, University of Perugia, Italy.
Abstract:
Malignant mesothelioma is a primary neoplasm of the serosal membranes that usually presents with a diffuse pattern of growth. However, cases of localized mesotheliomas have been described. The predominant localization is the pleura; peritoneum and pericardium being rarer localizations. Only few cases of true intraparenchymal mesothelioma arising in organs such as liver, gonads, lung, and pancreas have been described. We report a case of an otherwise healthy 48-year-old man without asbestos exposure with a nodule of 3 cm in diameter, localized in the spleen, discovered incidentally at the ultrasonographic examination, for which histopathological and immunohistochemical findings were consistent with epithelioid mesothelioma: large round cells with eosinophil dense cytoplasm and macronucleoli and with immunohistochemical positivity for pancytokeratins, calretinin, Wilms tumor-1, and others markers of mesothelial differentiation. The diagnosis of localized intrasplenic epithelioid malignant mesothelioma was carried out. To the best of our knowledge, this is the first case of a localized intrasplenic mesothelioma published in the indexed literature.
Insights
This report details the first documented case of localized epithelioid malignant mesothelioma within the spleen. This rare cancer finding highlights the spleen as a potential site for mesothelial neoplasms.
Area of Science:
- Oncology
- Pathology
Background:
- Malignant mesothelioma typically affects serosal membranes, often presenting diffusely.
- While pleural mesothelioma is most common, rarer sites include peritoneum and pericardium.
- Intraparenchymal mesotheliomas in organs like the liver, gonads, lung, and pancreas are exceptionally rare.
Observation:
- A 48-year-old man without asbestos exposure presented with an incidental 3 cm splenic nodule.
- Diagnostic imaging revealed a distinct mass within the spleen.
- Histopathological and immunohistochemical analyses were performed on the splenic nodule.
Findings:
- The splenic nodule exhibited features of epithelioid mesothelioma.
- Cells were large, round, with dense eosinophilic cytoplasm and prominent nucleoli.
- Immunohistochemistry confirmed mesothelial differentiation with positivity for pancytokeratins, calretinin, and Wilms tumor-1.
Implications:
- This case establishes the spleen as a potential, albeit rare, site for localized malignant mesothelioma.
- The findings expand the known spectrum of mesothelioma presentation and localization.
- This report is the first indexed literature case of intrasplenic malignant mesothelioma.
