Positron emission tomography/computed tomography in risk-factor-negative young female with malignant pleural mesothelioma: A case report and review of literature

Figure 4 Histopathological analysis of the resected specimen. A: Hematoxylin and eosin (HE) staining (× 400): Epithelioid tumor cells arranged in sheets, exhibiting large cell volume, eosinophilic cytoplasm, and marked nuclear atypia; B-D: Immunohistochemistry (IHC) (× 200); B: Calretinin: Strong and diffuse cytoplasmic/nuclear positivity in tumor cells; C: D2-40: Partial membranous positivity in tumor cells; D: WT-1: Focal nuclear positivity in tumor cells. The combined morphological and IHC profile (Calretinin+/CK5/6+/WT-1 focal+/TTF-1–) supports the diagnosis of epithelioid malignant pleural mesothelioma.