Multicystic peritoneal mesotheliomas are a rare benign subtype of mesothelioma.
On this page:
Terminology
The nomenclature for this condition can be confusing due to the use of multiple interchangeable synonyms that lump 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 them from peritoneal inclusion cysts, a term reserved for those cysts secondary to intra-abdominal inflammation and whose fluid content originates from the ovarian stroma.
Epidemiology
In contrast to malignant peritoneal mesothelioma, there is no association with asbestos exposure 5,8.
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.
Pathology
Typically comprises multiple grape-like clusters of cysts that are lined with mesothelium and separated by fibrous tissue components.
Location
Primarily occurs in the pelvic peritoneum, but can be multicompartmental 2.
Radiographic features
Ultrasound
May appear as a multicystic pelvic mass 2,3.
CT
typically seen as a well-defined low attenuating (cystic) pelvic mass
calcification is generally not a feature
MRI
Can better delineate the pelvic cystic mass. Reported signal characteristics include:
T1: fluid components show low signal
T2: fluid components show high signal
T1 C+ (Gd): may show enhancement of septa
Treatment and prognosis
The tumor can undergo malignant transformation. Treated with surgical removal alone, the tumor tends to recur locally (25-50% of cases) 3,6. The most widely accepted treatment therefore consists of complete surgical cytoreduction (i.e. excision) with hyperthermic intraperitoneal chemotherapy (HIPEC) 9. Nonetheless, it is thought not to be especially chemosensitive or radiosensitive 2. It may respond to hormonal therapy 5.
Differential diagnosis
The general differential includes:
abdominopelvic cystic lymphangioma: tends to affect younger patients
See also
-
mesothelioma (general article and discussion of pleural disease):