Small bowel (small intestine)
Benign tumors and tumor-like conditions
Benign cystic mesothelioma

Author: Nat Pernick, M.D. (see Authors page)

Revised: 16 February 2018, last major update August 2012

Copyright: (c) 2003-2018, PathologyOutlines.com, Inc.

PubMed Search: Benign cystic mesothelioma small bowel

Cite this page: Pernick, N. Benign cystic mesothelioma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/smallbowelbenigncysticmesothelioma.html. Accessed June 19th, 2018.
Definition / general
  • Also called multicystic mesothelioma
  • Rare tumor NOT associated with asbestos, occurs most frequently in women of reproductive age, difficult to diagnose preoperatively (J Med Case Reports 2010;4:385)
Clinical features
  • Often associated with prior pelvic surgery, endometriosis or pelvic inflammatory disease (J Obstet Gynaecol Res 2011;37:1126)
  • Some cases may be neoplastic, others may be caused by inflammation and adhesions (Int J Gynecol Pathol 2011;30:163)
  • Complete surgical resection recommended; follow up is necessary because 50% of tumors recur after excision
Case reports
  • 36 year old woman with multiple small cystic lesions in small bowel mesentery and pelvic peritoneum (Case of the Week #205)
Gross description
  • Usually large, may be multifocal or unilocular; free floating cysts may also occur
Gross images

Images hosted on other servers:

23 year old woman: multiple adherent cysts

Microscopic (histologic) description
  • Cysts are thin walled, may contain eosinophilic fluid
  • Mesothelial cells lining the cysts vary from flattened to endothelial-like to cuboidal
  • Inflammatory cells are often present within stroma between cysts
  • Foci of mesothelial hyperplasia may be present
Microscopic (histologic) images

Images hosted on PathOut server:

Case of the Week #205:

Various images


CD31

MNF116



Images hosted on other servers:

23 year old woman

72 year old woman

Positive stains
Differential diagnosis
  • Ascitis, loculated: usually has irregular borders, is surrounded by bowel loops or abdominal / pelvic organs
  • Cystic teratoma: usually contains adipose and calcifications
  • Lymphangioma: younger patients, may contain chylous fluid grossly, often lymphoid aggregates and smooth muscle within walls, D2-40+
  • Other mesenteric / omental cysts / pseudocysts: usually unilocular, no distinct cyst wall or internal septa, keratin-, calretinin-
  • Pseudomyxoma peritonei (mucinous peritoneal metastasis): may have coexisting omental caking, soft tissue peritoneal nodules and scalloping of the serosal margins of the liver or spleen