Mucinous tumors

Pseudomyxoma peritonei

Last author update: 1 July 2012
Last staff update: 19 October 2020

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PubMed Search: Ovarian pseudomyxoma peritonei

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Cite this page: Ehdaivand S. Pseudomyxoma peritonei. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/ovarytumorpseudomyxoma.html. Accessed June 5th, 2023.
Definition / general
  • Clinically represents abundant gelatinous pelvic / abdominal mucin or mucinous ascites accompanied by peritoneal lesions with bland to low-grade adenomatous mucinous epithelium intimately associated with pools of extracellular mucin and fibrosis
  • Peritoneal mucinous tumor / ascites almost always has mucinous epithelium present, if adequately sampled
  • Rare cases lacking mucinous epithelium usually do not recur
  • Virtually all cases have appendiceal, not ovarian origin

  • Three types of pseudomyxoma peritonei:
    • Superficial; mucin contains hyperemic organizing vessels and fibroblasts
    • Dissecting with fibrosis
    • Metastatic mucinous carcinoma

  • Mucin is associated with cystic epithelial implants on peritoneal surfaces, adhesions to bowel, abdominal wall and bladder; intestinal obstruction and peritonitis
  • Due to production of MUC2, a gel-forming mucin that forms strong bonds with stroma

  • Surgical pathology report:
    • Pseduomyxoma peritonei is NOT a pathologic diagnosis (Am J Surg Pathol 2000;24:1447)
    • Include whether mucin contains benign, borderline or malignant epithelium, plus whether mucin dissects into tissues forming a fibrous reaction
    • Benign or borderline epithelium should be diagnosed pathologically as disseminated peritoneal adenomucinosis
    • Malignant epithelium should be called disseminated peritoneal carcinomatosis
  • Excise as much tumor as possible, plus chemotherapy
Microscopic (histologic) images

AFIP images

Large pools of acellular mucin

Mucin spillage

Dissecting mucin with fibrosis in omentum

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