Peritoneal Cancer Differential Diagnoses

Updated: Feb 05, 2021
  • Author: Wissam Bleibel, MD; Chief Editor: N Joseph Espat, MD, MS, FACS  more...
  • Print

Diagnostic Considerations

The differential diagnosis of peritoneal cancers includes peritoneal metastasis (ie, peritoneal carcinomatosis) from primary sites including the GI tract, ovaries, or breast or as part of the syndrome of adenocarcinomas of unknown primary site. [16, 17] Although the primary histology findings dictate the clinical course, important concepts of diagnosis and treatment are common to all forms. The most important risk factor for developing peritoneal carcinomatosis is the depth of invasion of the primary tumor.

Reactive tumorlike lesions of the peritoneum have been described [18] and should be included in the differential diagnosis of primary peritoneal cancers. Granulomatous lesions include the following:

  • Vernix caseosa and meconium peritonitis
  • Granulomatous peritonitis secondary to foreign material, including keratin
  • Necrotic pseudoxanthomatous nodules
  • Postcautery granulomas

Nongranulomatous histiocytic lesions include the following:

  • Ceroid-rich histiocytic infiltrates
  • Peritoneal melanosis
  • Mucicarminophilic histiocytosis
  • Other histiocytic infiltrates

Fibrosing lesions include the following:

  • Sclerosing peritonitis
  • Peritoneal fibrosis nodules

Mesothelial lesions include the following:

  • Mesothelial hyperplasia
  • Peritoneal inclusion cysts

Pseudomyxoma peritonei typically includes any low-grade or benign tumor within the abdominal cavity that produces copious amounts of mucinous ascites. This condition includes peritoneal spread from well-differentiated adenocarcinomas of the GI tract and benign mucin-secreting adenomas of the appendix.

Differential Diagnoses