Well-differentiated Papillary Mesothelioma (WDPM) is a variant of Epithelial Mesothelioma. It is generally regarded as an uncommon tumor of low malignant potential, predominantly affecting women of productive age, some of whom have been exposed to asbestos through their job, had contact with a household member who had been exposed at work, but can also develop without being exposed to asbestos. This rare type of tumor typically presents itself in the peritoneum of women, and in rare cases men, but has also shown up in the percardium, pleura, as a peritoneal tumor, or as tunica vaginalis.
Symptoms range from ascites, abdominal pain, cramping and/or constipation. Patients with tumors arising in the pleura most commonly present with difficult or labored breathing of gradual onset and/or recurrent pleural effusions. In cases of WDPM of the tunica vaginalis the tumor can manifest as a hydrocele.
In the majority of cases, patients who have been diagnosed with WDPM usually have benign tumors or tumors that behave in an indolent fashion. However, there have also been cases in which the prognosis is bleak.
The prognosis of patients who have been diagnosed with WDPM can vary depending on the type of treatment as well as the stage of the disease once detected. Other factors used by medical professionals to determine the prognosis are gender, age, stage of the disease, location of the tumor once detected, microscopic invasion and tumor multifocality. Patients tend to live 6 month to 15 years from the time they have been diagnosed, but patients have also continued to live beyond the typical reported cases.
Transmission electron microscopy has been used to detect WDPM as well as electron photomicrographs, and light miscroscopy using a sodium hypochrlorite digestion procedure.
There are several treatment options available: adjuvant chemotherapy. A more aggresive approach using chemotherapy has also been used to treat WDPM with a mixed response on effectiveness.
Patients with WDPM generally have a far better prognosis than those diagnosed with DMM.
Unlike the conclusive link between asbestos exposure and diffuse malignant mesothelioma, and association between WDPM and asbestos has not be established, however clinicians have found that in some instances, patients with WDPM either worked in an occupation with a high probability of asbestos exposure, had contact with a household member occupationally exposed to asbestos. The length of exposure for these patients ranged from 2.5 to 35 years of asbestos exposure. Well-differentiated Papillary Mesothelioma exhibits a wide array of clinical behavior, ranging from complete resolutions after adjuvant therapy to dessenminated disease resulting in death.
The majority of cases have been reported in the peritoneum in women of reproductive age with no history of asbestos exposure and also in the tunica vaginalis of men. Cases have also been reported in the pleura. WDPM is often discovered incidentally during abdominal or pelvic surgery. The tumor has an indolent clinical course and with a varied prognosis. Occasional cases are more aggressive and require long term clinical follow-up, and have even led to death.
