Well-Differentiated Papillary Mesothelioma

What is Papillary Mesothelioma?



Well-differentiated papillary mesothelioma (WDPM) of the peritoneum is a rare subtype of peritoneal epithelioid mesothelioma which typically has low malignant potential. This form of mesothelioma, in contrast with the conventional diffuse malignant mesothelioma (DMM), is considered to be of low malignant potential, or not likely to spread or invade other parts of the body.

It most commonly occurs in young women lacking a history of asbestos exposure. Only 38 female patients with peritoneal WPDM have been reported in the literature, and no uniform treatment recommendation has been established.

Well-Differentiated Papillary Mesothelioma.

Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA. butno001@mc.duke.edu

Well-differentiated papillary mesothelioma is an unusual variant of epithelial mesothelioma considered to be of low malignant potential.

The majority of previously reported cases developed in the peritoneum of young women without a history of asbestos exposure. The authors report 14 cases of well-differentiated papillary mesothelioma, seven of which originated in the pleura, six in the peritoneum, and one in the tunica vaginalis. Eleven of the patients were male and three were female, with an average age at presentation of 58 years (range 32-82 years). Six of the patients had a quantifiable history of asbestos exposure. Of the nine cases with complete follow-up, six had clinically indolent disease, one showed resolution after adjuvant chemotherapy, one pursued an aggressive course, and one died of other causes. These findings indicate that well-differentiated papillary mesothelioma is a rare variant of mesothelioma with a variable clinical prognosis that is etiologically related to asbestos exposure in some cases.

PMID: 11688466 [PubMed - indexed for MEDLINE

Macroscopic features: Multiple grey white nodules usually less than 20mm in diameter.

Microscopic features:

Well defined stout papillary structures with myxoid cores, lined by bland, flattened, single layer of cuboidal or columnar mesothelial cells. Subnuclear vacuolation may be noted. Mitotic figures are rarely present. In some cases there may be limited invasion of the submesothelial layer. Deep invasion is usually not seen.

Differential diagnosis:

1. Reactive mesothelial hyperplasia (assocciated with inflammation) ;
2. Serous neoplasia of peritoneum ( cellular stratification, atypia and mitotic figures) ;
3. Primary and seconday adenocarcinoma (mucin histochemistry and immunohistochemistry are useful ) ;
4. Diffuse mesothelioma with a prominent tubulopapillary epithelial component (diffuse growth pattern & cytological atypia).
   

Papillary Mesothelioma Treatments

Due to the rare occurrence of this disease, a recommendation of uniform treatment has yet to be established. The typical forms of treatment that have been documented in various studies are similar to traditional mesothelioma treatments and have included surgery and multiple forms of chemotherapy. Patients and their families often have numerous questions about the best way to combat mesothelioma and we offer a comprehensive packet with information about treatment options and top doctors, catered to each patient’s specific diagnosis. Please click here to receive this complimentary packet overnight.