Malignant peritoneal mesothelioma - localized

Case contributed by Dr Cristina Prado


Patient presents with a partial bowel obstruction and weight loss. She has a past history of a hysterectomy and bilateral oophorectomy over 20 years ago (indication for this is not evident)

Patient Data

Age: 82 years
Gender: Female

MRI Pelvis

Magnetic resonance imaging (MRI) study showed a solid mass of about 7 cm x 5.3 cm x 5.6 cm in diameter, involving the upper the vaginal vault, with intermediate signal on T1, predominantly hypointense on T2-weighted sequences with small cystic areas / necrosis. 

Administration of contrast shows heterogeneous enhancement, more intense in later stages. The mass has a restrictive pattern on diffusion sequences.

The mass demonstrates no cleavage plane with the rectosigmoid, which appears displaced and thick walled. There is poor definition in outline in relation to soft tissue adjacent to the right lateral wall of the pelvis. No enlarged lymph nodes in the pelvis.
Nor do we show lymphadenopathy in the retroperitoneum.
No free fluid in the pelvis displayed.

Case Discussion

This study demonstrates a large pelvic mass with infiltration of adjacent organs and diffusion restriction indicating aggressiveness of the lesion. Because its large size is difficult to establish the exact anatomical origin. Possibilities include:

  • ovarian or uterine neoplasm (unlikely with a history of hysterectomy and oophorectomy 20 years ago)
  • rectosigmoid neoplasm 
    • adenocarcinoma but there is too much extraluminal component and the mucosa appears respected
    • GIST but infiltration of neighboring structures is rare
  • mesenteric or peritoneal tumor (e.g. desmoid tumor, solitary fibrous tumor, leiomyosarcoma, malignant mesothelioma)

Since the mass has a slight enhancement after contrast administration, more evident in later stages, and GIST, the desmoid tumor, solitary fibrous tumor and leiomyosarcoma are hypervascular, with intense enhancement in the early stages, we favored a malignant peritoneal mesothelioma.

This was subsequently confirmed by histological study.

Acknowledgments: I'm grateful to Dra. M. Arias, Dr. A. Iglesias Castañón (GALARIA-Vigo)

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Case information

rID: 14666
Published: 20th Aug 2011
Last edited: 16th Sep 2018
Inclusion in quiz mode: Excluded

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