A 62 year old male who had been operated for a carcinoma of the rectum presented with pain and distension of the abdomen. The CT scan showed a fluid with a density more than simple fluid and scalloping of the liver. A diagnosis of pseudomyxoma peritonei was made. There was no evidence of a rectal tumour.
The term pseudomyxoma peritonei was used by Werth to describe a patient with ruptured ovarian cystadenoma and gelatinous intraperitoneal material. It is a term used to describe a clinical picture associated with release of intraperitoneal mucin from malignant and benign tumours. The malignant tumours associated with pseudomyxoma peritonei are low grade tumours, usually of the appendicular ovarian origin. The cells produce mucin but have a very low metastatic potential. This results in a predominant intraperitoneal growth resulting in accumulation of mucin and severe abdominal dissention and symptoms.
The CT scan shows scalloping of the liver and spleen. Scalloping is distortion of the liver/spleen margins because of extrinsic pressure of adjacent peritoneal implants without liver parenchymal metastasis. There is ascitic fluid that is slightly denser than simple fluid density. Occasionally amorphous calcifications may be seen. Primary tumour is usually not visible at diagnosis. Scalloping of the liver and ascitic fluid with a greater than fluid density is seen on this scan.
The outcome of pseudomyxoma peritonei depends of the malignant potential and the origin of the tumour responsible for pseudomyxoma. Appendiceal tumours have the best outcome and gastric tumours have the worst outcome. Tumours which show invasive features have a worse outcome.
The disease is treated by surgical debunking. Intraperitoneal chemotherapy may be given. Hyperthermic intraperitoneal chemotherapy (HIPEC) or early post-operative intraperitoneal chemotherapy (EPIC) may be given. HIPEC is associated with better tolerability, lesser adverse effects and better survival.