Pseudomyxoma peritonei presenting with pyloric obstruction: a case report.

Pseudomyxoma peritonei (PMP) is a rare malignancy characterized by mucinous ascites. Gastric outlet obstruction (GOO) due to extrinsic compression is exceptionally uncommon. We present a 76-year-old male with high-grade appendiceal mucinous neoplasm presented with progressive abdominal pain, nausea, and vomiting. Imaging demonstrated extensive peritoneal disease causing pyloroduodenal compression. Five sequential self-expanding metal stents were placed, providing only transient relief due to persistent compression and tumour overgrowth. With worsening nutritional status, a multidisciplinary team pursued a palliative approach. An endoscopic gastrojejunostomy was performed alongside total parenteral nutrition and nasogastric decompression, resulting in sustained symptom relief and improved quality of life. PMP-related GOO poses significant management challenges. Endoscopic stenting may be ineffective in diffuse mucinous disease. Early consideration of bypass procedures, such as gastrojejunostomy, combined with multidisciplinary care and nutritional optimization, is essential for durable palliation.