Primary malignant peritoneal mesothelioma mimicking tuberculous peritonitis: A case report

Figure 1 Abdominal contrast-enhanced computed tomography. A: Axial view, contrast-enhanced computed tomography (CT) showed diffuse fat stranding infiltration within the greater omentum; B: Axial view, thickening of the pelvic peritoneum was enhanced by contrast material; C: Coronal view of the contrast-enhanced CT showed irregular thickening of the perihepatic peritoneum and minimal ascites over the bilateral subphrenic spaces, paracolic gutter, and pelvic cavity.

Figure 2 Laparoscopy. A: Multiple whitish nodules were observed over the entire abdominal cavity with some yellow ascites; B: Grossly red nodular tissue was located on the peritoneum.

Figure 3 Pathological findings of the lesion on the peritoneum. A: The peritoneum revealed mesothelioma invasion into the stroma and adipose tissue composed of a tubular or single-cell arrangement of epithelioid cells (x 40; HE stain); B: The tumor cells had large, oval-round nuclei, conspicuous nucleoli, and moderate eosinophilic cytoplasm (x 400; HE stain).

Figure 4 The immunohistochemical staining results. A: Immunohistochemically, the tumor cells were positive for calretinin (nuclear and cytoplasmic staining, x 200); B: The tumor cells were focally positive for WT-1 (x 200); C: TTF-1 immunostaining was negative for tumor cells (x 200); D: CDX-2 immunostaining was negative for tumor cells (x200).

Figure 5 Additional staining results. A: Ki-67 proliferative index was < 10%(x 100); B: Napsin A immunostaining was negative for tumor cell (x 100).