Case Presentation: A 59-year-old female with a past medical history of hypertension, alcohol use disorder, and type 2 diabetes mellitus presented to the emergency department for one month of progressive abdominal distention, weight gain, dyspnea on exertion, early satiety, and increased reflux. She endorsed significant alcohol use with 1.5 gallons of liquor intake per week for multiple years. She was not up to date with her age-appropriate cancer screenings. She denied a personal or family history of cancer. Of note, she endorsed potential asbestos exposure from fire-damaged old homes during childhood. The patient’s physical exam was notable for a severely distended abdomen with an overt fluid wave. Initial computed tomography of the abdomen/pelvis revealed hepatomegaly of 21 centimeters with large-volume intraperitoneal ascites and scattered increased attenuation of the anterior peritoneum, anterior mesenteric fat, and omentum. There was no evidence of synthetic liver dysfunction; however, her CA-125 level was elevated at 226 U/mL, raising suspicion for malignancy. A diagnostic paracentesis yielded a serum albumin to ascites gradient of 0.8 and numerous reactive mesothelial cells. While awaiting cytology results, the patient underwent an MRI pelvis with contrast that demonstrated bilateral intraovarian lesions concerning for primary ovarian neoplasm. During the patient’s hospitalization she underwent multiple paracenteses, draining a total of 9 liters of ascitic fluid. She was discharged home with plans to follow up with gynecologic oncology for final diagnosis and definitive management. One week after discharge, cytology returned favoring Mullerian/gynecologic high-grade adenocarcinoma. The patient underwent cytoreductive surgery with total hysterectomy, bilateral salpingo-oophorectomy, portal lymph node excision, and omentectomy. One month later, final pathology confirmed peritoneal epithelioid mesothelioma involving the uterine serosa, bilateral fallopian tubes, bilateral ovaries, omentum, small bowel adhesions, and peritoneum.
Discussion: Malignant peritoneal mesothelioma (MPM) is a rare disease with an incidence of about 1 case per million people each year and is often associated with a poor prognosis. The oncogenesis is multifactorial and can result from germline mutations, radiation, environmental exposures such as asbestos, and chronic abdominal inflammation. While common presenting symptoms include abdominal pain and distension, clinical manifestations can be vague and cause delay in diagnosis. We present a patient whose initial diagnosis was initially thought to be metastatic Mullerian adenocarcinoma based on paracentesis cytology but was subsequently found to have MPM on final uterine histopathology.
Conclusions: Two treatment pathways exist for patients diagnosed with MPM: cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC) or systemic chemotherapy with potential immunotherapy and surgery. Systemic chemotherapy regimens generally consist of carboplatin and pemetrexed. This patient is currently on systemic chemotherapy with surveillance imaging showing improvement in disease burden, though she still requires regular therapeutic paracenteses to manage her symptoms. MPM is a rare diagnosis with high mortality rates leading to difficulty in establishing treatment standards. We present this case in hopes of expanding the minimal literature written on MPM with the goal of eventual improved treatment options and outcomes.