PMC8595014_01
(a, b) Axial T2 images of the midabdomen and pelvis showing ascites (red arrows) and peritoneal thickening (yellow arrows). (c, d) Axial T2 fat-saturated images of the midabdomen and pelvis showing ascites (red arrows) and peritoneal thickening (yellow arrows).
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A moderate to large volume of ascites was also present (Figures 1 and 2).
Coronal images before (a) and after (b) the administration of contrast demonstrating enhancement of the peritoneum and omentum.
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A moderate to large volume of ascites was also present (Figures 1 and 2).
(a) T1 coronal images precontrast and (b) T1 postcontrast images demonstrating enhancing pleural nodules.
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MRE also revealed enhancing nodules along the superior surface of the diaphragm (Figure 3).
(a) Axial CT with intravenous contrast of the chest demonstrating pleural-based nodules. (b) Coronal CT with intravenous contrast of the chest demonstrating pleural nodules.
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The nodules were further evaluated with a dedicated CT chest, abdomen, and pelvis with intravenous contrast that showed two nodular masses along the anterior surface of the diaphragm, suspicious for a mesothelial process (Figure 4) and thickened, enhancing omentum and ascites (Figure 5).
Contrast-enhanced axial (a) and coronal (b) CT images demonstrating omental thickening (yellow arrows) and ascites (red arrows).
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The nodules were further evaluated with a dedicated CT chest, abdomen, and pelvis with intravenous contrast that showed two nodular masses along the anterior surface of the diaphragm, suspicious for a mesothelial process (Figure 4) and thickened, enhancing omentum and ascites (Figure 5).
Ultrasound images of the left lower quadrant (a) and right lower quadrant (b) demonstrating ascites (red arrows) and omental thickening (yellow arrows).
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Ultrasound of the abdomen redemonstrated a thickened omentum with complex ascites due to tumor (Figure 6).
Sheets of neoplastic mesothelial cells with foci of chronic inflammation (pictured). Stains for calretinin, CK 5/6, and WT-1 were positive, confirming mesothelioma (not shown in this image).
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The biopsy specimen revealed sheets of neoplastic mesothelial cells with foci of chronic inflammation (Figure 7).
Top images (a-c): initial PET/CT demonstrating FDG avid thickening of the peritoneum and omentum (yellow arrows) and FDG avid nodules along the anterior diaphragm (green arrows). Bottom images (d-f): PET/CT 2 months later with decreased FDG avidity of the peritoneum and omentum (yellow arrows) and nodules along the anterior diaphragm (green arrows).
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FDG avidity of the thickened peritoneum and pleural-based nodules along the diaphragm (Figure 8). Follow-up PET/CT after the third cycle of IV chemotherapy demonstrated decreased FDG avidity in the omentum, peritoneum, and pleural nodules (Figure 8). Follow-up MRI after 5 cycles of IV chemotherapy had persistent but decreased peritoneal thickening/enhancement with resolution of ascites, and the diaphragmatic nodules were decreased in size (Figure 9).
MRI of the abdomen and pelvis three months after the patient's initial MR left T1 precontrast (a), middle T1 postcontrast (b), and right T1 postcontrast (c) showed persistent but decreased peritoneal thickening/enhancement. Pulmonary nodules are decreased in size. No significant ascites is seen.
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Follow-up PET/CT after the third cycle of IV chemotherapy demonstrated decreased FDG avidity in the omentum, peritoneum, and pleural nodules (Figure 8). Follow-up MRI after 5 cycles of IV chemotherapy had persistent but decreased peritoneal thickening/enhancement with resolution of ascites, and the diaphragmatic nodules were decreased in size (Figure 9).