P1683 - Case Study: Pseudomyxoma Peritonei Secondary to Rectal Mass Adenocarcinoma: A Rare Clinical Presentation

Milaris Sanchez-Cordero, MD¹, Natalia Canevaro-Lugo, MD², Kathy Caraballo-Rivera, MD^2
1Mayaguez Medical Center, Mayaguez, Puerto Rico; ²Bayamon Medical Center, Bayamon, Puerto Rico

Introduction: Pseudomyxoma peritonei (PMP) is a rare malignant disease, involving the peritoneum, characterized by the production of large quantities of mucinous ascites. PMP has a low incidence of 2-4 per million people, it’s challenging to diagnose, and has a limited prognosis. Normally, it’s extremely rare but the most common presentation is PMP induced by low-grade appendiceal mucinous neoplasm.

Case Description/Methods: . This reports a case of a 76-year-old female who presented to the Emergency Department due to abdominal pain, rectal mass with bleeding of several months of evolution. The patient has poor medical follow-up and has never had a colonoscopy before. A sigmoidoscopy was performed on admission alongside a biopsy of the rectal mass that resulted with adenomatous colon mucosa with positive immunostain (CK-20). Pathology from ultrasound-guided paracentesis and biopsy results came back positive with PMP primarily from adenocarcinoma from the rectum. CEA resulted elevated. The patient presented with pulmonary embolism (PE) occluding the right-upper-lobe (RUL) with bilateral lower extremities deep vein thrombosis (DVT). Due to a hypercoagulable state, an inferior vena cava (IVC) filter was placed. Diagnostic laparoscopy was performed and resulted with carcinomatosis in the peritoneal cavity. An attempt to do a colostomy for the palliative process was not possible due to extension of tumor to bowel. Cytoreductive Surgery (CRS) associated with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is the optimal treatment for PMP. However, in patients with an extensive or recurrent disease, few therapeutic opportunities are available.

Discussion: In this case, tumor marker elevations correlate with worse prognosis and increased recurrence rates. This case showed us the importance of follow up with primary care physicians for an early diagnosis and colonoscopy as indicated by guidelines to avoid fatal outcomes.



Disclosures:


Milaris Sanchez-Cordero, MD¹, Natalia Canevaro-Lugo, MD², Kathy Caraballo-Rivera, MD². P1683 - Case Study: Pseudomyxoma Peritonei Secondary to Rectal Mass Adenocarcinoma: A Rare Clinical Presentation, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.