multicystic mesothelioma

Multicystic mesotheliomas are a rare benign subtype of mesothelioma.


The nomenclature for this condition can be confusing due to the use of multiple interchangeable different synonyms that put it together with the peritoneal inclusion cysts. Although there is still some debate on this matter, this article will refer to multicystic mesotheliomas as true neoplasms, distinguishing it from peritoneal inclusion cysts, a term reserved for those cysts secondary to intra-abdominal inflammation and with its fluid content originated from the ovarian stroma.


Different from malignant peritoneal mesothelioma, there is no association with asbestos exposure .

Clinical presentation

Patients generally present with non-specific symptoms such as abdominal or pelvic pain, or distension. A palpable abdominal or pelvic mass may eventually be felt on clinical examination.


Typically comprises multiple grape-like clusters of cysts which are lined with mesothelium and separated by fibrous tissue components.


Primarily occurs in the pelvic peritoneum, but can be multicompartmental .

Radiographic features


May appear as a multicystic pelvic mass .

  • typically seen as a well-defined low attenuating (cystic) pelvic mass
  • calcification is generally not a feature 

Can better delineate the pelvic cystic mass. Reported signal characteristics include:

  • T1: fluid components show low signal 
  • T2: fluid components show high signal
  • C+ (Gd): may show enhancement of septa

Treatment and prognosis

Surgery is the preferred option for localized lesions. The tumor tends to recur locally (25-50% of cases) . Not thought to be chemo- or radiosensitive . May respond to hormonal therapy .

Differential diagnosis

The general differential includes:

See also