Skip to main content
. 2021 Sep 1;41(5):1368–1386. doi: 10.1148/rg.2021200207

Figure 4g.

MCPM in a 34-year-old woman. (a–d) Axial (a), coronal (b), and sagittal (c) T2-weighted images and axial T1-weighted image (d) show a multiloculated cystic mass (straight arrow) with thin septa (arrowheads) in the pelvis. The mass arises from the pelvic peritoneum, infiltrates around bowel loops, and surrounds the right ovary. Most loculi contain simple T2-hyperintense fluid (* in a–c), which is hypointense on the T1-weighted image (* in d); however, one loculus (curved arrow in a and d) shows increased signal intensity on both T1-weighted and T2-weighted images, consistent with internal blood contents. Incidentally noted are T1-hyperintense hemorrhagic cysts in the right ovary (straight arrow in d); the lateral cyst contains layering T1-hyperintense blood products, and the superomedial cyst has a T2-hypointense rim (straight arrow in a). (e, f) Photographs of a whole (e) and cut (f) gross specimen show the multicystic nature of a peritoneal mesothelioma, with a grapelike appearance of the whole specimen (arrow in e). The cut specimen shows the mass to be comprised of innumerable cystic spaces of varying size separated by a thin fibrovascular stroma (arrowhead in f), which matches the appearance at MRI. (g, h) High-power photomicrographs with H-E stain (g) and calretinin immunohistochemical stain (h) show multiple small cystic spaces (*) lined by cuboidal mesothelium (arrow), which stains positive for calretinin, a mesothelial marker. (Original magnification, ×100.)

MCPM in a 34-year-old woman. (a–d) Axial (a), coronal (b), and sagittal (c) T2-weighted images and axial T1-weighted image (d) show a multiloculated cystic mass (straight arrow) with thin septa (arrowheads) in the pelvis. The mass arises from the pelvic peritoneum, infiltrates around bowel loops, and surrounds the right ovary. Most loculi contain simple T2-hyperintense fluid (* in a–c), which is hypointense on the T1-weighted image (* in d); however, one loculus (curved arrow in a and d) shows increased signal intensity on both T1-weighted and T2-weighted images, consistent with internal blood contents. Incidentally noted are T1-hyperintense hemorrhagic cysts in the right ovary (straight arrow in d); the lateral cyst contains layering T1-hyperintense blood products, and the superomedial cyst has a T2-hypointense rim (straight arrow in a). (e, f) Photographs of a whole (e) and cut (f) gross specimen show the multicystic nature of a peritoneal mesothelioma, with a grapelike appearance of the whole specimen (arrow in e). The cut specimen shows the mass to be comprised of innumerable cystic spaces of varying size separated by a thin fibrovascular stroma (arrowhead in f), which matches the appearance at MRI. (g, h) High-power photomicrographs with H-E stain (g) and calretinin immunohistochemical stain (h) show multiple small cystic spaces (*) lined by cuboidal mesothelium (arrow), which stains positive for calretinin, a mesothelial marker. (Original magnification, ×100.)