P3053 - A Rare Case of Malignant Peritoneal Mesothelioma With Diffuse Peritoneal Carcinomatosis

Hamzah A. Qudah, MD¹, Arundhati Chandini Arjun, MD¹, Mohamad Hamad, MD¹, Shweta Nelluri, MD¹, Thomas C. Fiest, DO^2
1Monmouth Medical Center, Long Branch, NJ; ²Gastroenterology Group of New Jersey, Oakhurst, NJ

Introduction: Malignant peritoneal mesothelioma (MPM) constitutes 10-15% of all cases of mesothelioma. As with pleural mesothelioma, MPM is also associated with asbestos exposure although to a lesser extent (33-50% vs. >80%). We present a patient with history of asbestos exposure who was diagnosed with peritoneal mesothelioma without extension.

Case Description/Methods: A 54-year-old Hispanic M with history of DM who came with LLQ abdominal pain of 3 days duration with intermittent nausea and decreased appetite. He has history of asbestos exposure for 20 years. He had a 20-pack year history of smoking. On exam, vitals were normal, abdomen was moderately tender to palpation in the LLQ with no guarding or tenderness. Labs were normal except for elevated CRP and ALP. CT of his abdomen in Figure 1, showed extensive diffuse peritoneal carcinomatosis likely rectosigmoid in origin, with confluent metastatic implants. Chest CT and Bone scan were negative. CA-19-9, CEA, AFP were negative. A peritoneal mass biopsy revealed a malignant epithelioid tumor which stained positive for MCK, calretinin, WT1, D2-40 and negative for other markers. These findings were consistent with a peritoneal carcinomatosis from a primary malignant peritoneal mesothelioma. The patient was referred to surgical oncology for Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) given no extension on CT.

Discussion: MPM comprises 0.2% of all neoplasms and its median age at presentation is 51 to 59 with a male to female ratio of 1:1. MPM spreads by expansion rather than infiltration, with symptoms related to tumor spread within the abdominal cavity. It presents with nonspecific symptoms of abdominal distension, early satiety, and weight loss. MPM anatomically is classified as either diffuse (more common) or localized disease. Histologically, they are classified as epithelioid, sarcomatoid or biphasic. Initial investigation of choice is CT-Abdomen and pelvic showing diffuse and widespread involvement of the peritoneal cavity, tumor infiltration, and irregular/nodular thickening of the peritoneum in a sheet-like fashion. Histopathological confirmation is achieved via CT-guided core needle biopsy or laparoscopically. Most mesotheliomas stain positive for calretinin, cytokeratins 5/6, WT-1 and D2-40. Treatment currently is best achieved via CRS & HIPEC with median survival of 53 months. Our patient’s acute presentation and unique CT image findings are an amazing addition to the literature.


Figure: Contrast-enhanced axial CT show extensive peritoneal carcinomatosis with soft tissue implantation. The yellow arrow in image (A) portrays subphrenic soft tissue deposits, some of which exhibit mass effect onto the liver. The red arrow in image (B) points to soft tissue deposits in the left upper quadrant mesentery, likely representing metastatic implants. The orange arrows in images (C) – (E) demonstrate extensive omental/peritoneal soft tissue deposits with nodular thickening consistent with peritoneal carcinomatosis. The blue arrow in image (F) reveals small amount of fluid in the mid abdomen.


Disclosures:
Hamzah Qudah indicated no relevant financial relationships.
Arundhati Chandini Arjun indicated no relevant financial relationships.
Mohamad Hamad indicated no relevant financial relationships.
Shweta Nelluri indicated no relevant financial relationships.
Thomas Fiest indicated no relevant financial relationships.


Hamzah A. Qudah, MD¹, Arundhati Chandini Arjun, MD¹, Mohamad Hamad, MD¹, Shweta Nelluri, MD¹, Thomas C. Fiest, DO². P3053 - A Rare Case of Malignant Peritoneal Mesothelioma With Diffuse Peritoneal Carcinomatosis, ACG 2021 Annual Scientific Meeting Abstracts. Las Vegas, Nevada: American College of Gastroenterology.