Pseudomyxoma peritonei originating from small intestine: A case report and review of literature.

backgroundPseudomyxoma peritonei (PMP) is a distinct form of peritoneal malignancy characterized by diffuse intra-abdominal gelatinous ascites, with an estimated incidence of 1-3 per 1000000. PMP is predominantly secondary to appendiceal mucinous neoplasms, with rarer origins including the ovaries, colon, and urachus. However, PMP originating from small intestine is extremely rare. CASE SUMMARY: A 60-year-old male patient presented with anorexia and abdominal distension. Computed tomography revealed the presence of abdominopelvic effusions and multiple intra-abdominal space-occupying lesions. Ultrasound-guided aspiration indicated that the aspirated tissue was mucinous. Exploratory laparoscopy and tissue biopsy identified diffuse tumor nodules in peritoneum, omentum, pelvic region, intestinal walls, and mesentery. Histopathological analysis of the resected tumors confirmed the presence of mucinous adenocarcinoma, but the primary lesion was difficult to determine. The patient was referred to our center for further treatment and underwent cytoreductive surgery (CRS) combined with hyperthermic intraperitoneal chemotherapy (HIPEC) under general anesthesia. The intraoperative peritoneal cancer index was 30. The surgery lasted 8 hours, with a blood loss of about 600 mL. A complete cytoreduction (CCR0) was achieved. No serious complications occurred after surgery, and the patient's condition was good during the telephone follow-up. Postoperative pathology confirmed the diagnosis of small intestinal mucinous adenocarcinoma at proximal jejunum, which was complicated by high-grade PMP.

conclusionPMP originating from small intestine is an exceptionally rare entity that exhibits non-specific clinical features. The preferred treatment is CRS + HIPEC.