Papillary Mesothelioma

Papillary mesothelioma, also known as well-differentiated papillary mesothelioma (WDPM), is a relatively uncommon form of epithelial mesothelioma that primarily occurs in the linings of internal organs, including the peritoneum (abdomen), pleura (lungs), or tunica vaginalis (testicles).

Papillary Mesothelioma’s Impact on Women

Well-differentiated papillary mesothelioma (WDPM) is distinct in its growth pattern, exhibiting a slow progression at the microscopic level, setting it apart from the more aggressive sarcomatoid mesothelioma. The cellular structure of papillary mesothelioma often features cells that are round or oval, which cluster together to form finger-like structures or papillae. Predominantly, this subtype occurs in young women, especially those with a medical history that includes endometriosis and ovarian cancer, indicating a demographic predisposition.

Unlike other mesothelioma forms, papillary mesothelioma specifically targets the linings of internal organs, highlighting its unique site of impact. Additionally, on rare occasions, this subtype may present with psammoma bodies, indicative of calcification spots within the tumor, further distinguishing it from other mesothelioma types.

Is Papillary Mesothelioma Benign?

Typically, papillary mesothelioma is considered benign and does not often recur after treatment. However, there have been reported cases of WDPM becoming malignant over time, which underscores the importance of accurate diagnosis.

The Connection with Asbestos Exposure

Studies have suggested a potential link between papillary mesothelioma and asbestos exposure. In a review of pleural WDPM cases, approximately half of the patients had confirmed occupational asbestos exposure. However, due to the rarity of this subtype and challenges in diagnosis, comprehensive data on this association remain limited.

Symptoms

The majority of individuals diagnosed with papillary mesothelioma do not exhibit noticeable symptoms. Symptoms, if present, vary based on the tumor’s location:

• Peritoneal Papillary Mesothelioma: Symptoms may include abdominal pain, bloating (peritoneal effusion), pelvic mass, and pelvic pain.
• Pleural Papillary Mesothelioma: Symptoms can include a collapsed lung (pneumothorax), inflammation of the pleura and pericardium (pleuropericarditis), pleural effusion, pleural thickening, and shortness of breath (dyspnea).
• Tunica Vaginalis Papillary Mesothelioma: Symptoms may involve a fluid-filled sac around the scrotum (hydrocele), scrotal nodules, and scrotal swelling.

Due to the absence of symptoms in most cases, accurate diagnosis can be challenging.

Diagnostic Methods

Papillary mesothelioma is often diagnosed incidentally during other medical procedures. Diagnostic methods include biopsies, histology and pathology analysis, imaging scans, and immunohistochemistry. Biopsies are particularly essential for confirming the diagnosis and characterizing the tumor cells.

Prognosis and Treatment

WDPM typically has a favorable prognosis, with patients potentially surviving for many years. For instance, the most common type affecting the peritoneum has a 5-year survival rate of approximately 90% with treatment. Long-term monitoring is recommended due to limited research on this subtype. Treatment options vary but may include surgical tumor removal, cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), early postoperative intraperitoneal chemotherapy (EPIC), immunotherapy, or multimodal treatment, depending on factors such as malignancy.