A0652 - A Case of Diffuse Malignant Peritoneal Mesothelioma

Ariana R. Tagliaferri, MD¹, Gabriel Melki, MD¹, Walid Baddoura, MD^2
1Saint Joseph's University Medical Center, Paterson, NJ; ²St. Joseph's Regional Medical Center, Paterson, NJ

Introduction: Malignant Mesothelioma occurs most commonly in the pleural space but can also occur in the peritoneum in those with an extensive history of asbestos exposure. Peritoneal mesothelioma (MPeM) is relatively rare accounting for 15% of all mesotheliomas. Most patients are asymptomatic until advanced stages but will present with nonspecific abdominal symptoms. We present a case of MPeM in a male who worked in a wire hanger factory for 20 years.

Case Description/Methods: An 81-year-old Arabic male presented with nausea, vomiting, abdominal distention and diarrhea lasting three weeks. His vitals were remarkable for hypertension (192/102 mmHg), and he had diffuse abdominal tenderness without peritonitis on physical exam. CT A/P with contrast showed fluid distending the small and large bowel and mild fat stranding and wall thickness of the ascending and descending colon. Ascites was also noted. Laboratory studies revealed elevated ALT (54 unit/L) with otherwise normal AST, ALP and bilirubin. CRP (87 mg/L), ESR (30 mm/hr) and WBC’s (12.9 x10^3/mm3) were all elevated. A repeat CT A/P was suggestive of small bowel obstruction and he underwent a diagnostic laparoscopy with right hemicolectomy, ileocolonic anastomosis and omentectomy. The resected obstructing mass was diffuse MPeM, epithelioid type extensively involving the small bowel muscularis propria and submucosa and focally involving the lower mucosa of the ileocecal region (T0N0). Immunohistochemical analysis showed strong positive reactions with calretinin, CK 5/6, WT-1 and D2-40. Negative reaction was present with CK20, synaptophysin, chromogranin, and prostatic markers. He received 12 cycles of nivolumab, 7 cycles of ipilibumab and palliative radiation due to increasing tumor burden but was ultimately transferred to hospice approximately 2 years after initial diagnosis.

Discussion: MPeM as the primary source of mesothelioma is uncommon. Asbestos exposure confers a lower risk of MPeM in males. Patients with MPeM are typically younger at the time of diagnosis than those with pleural involvement and are usually women. Females have prolonged survival due to less aggressive histological subtypes, such as epithelial. The 3- year survival rate for MPeM after treatment is 39% for males. Our patient was 81 years-old at time of diagnosis and was a male who was likely exposed to asbestos for over 20 years. He outlived his life expectancy given his age, gender, location of mesothelioma, etiology and histological subtype.


Disclosures:


Ariana R. Tagliaferri, MD¹, Gabriel Melki, MD¹, Walid Baddoura, MD². A0652 - A Case of Diffuse Malignant Peritoneal Mesothelioma, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.