Pseudomyxoma peritonei ( PMP ) – a rare entity

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Clinical findings and complications
While the exact pathogenesis of PMP is controversial, clinical morbidity and mortality results from the fact that copious amounts of extracellular and peritoneal mucin cause distortion and loss of function of visceral organs. 3Subsequent unrelieved compression can lead to adhesions and further morbidity, including small-bowel obstruction, renal or caval obstruction, and death.Because of the viscous, gelatinous and septated nature of the mucus, it cannot be drained by paracentesis.Impending bowel obstruction, renal compromise and discomfort may be relieved by repeated laparotomy for debridement of the mucin and subsequent decompression of the viscera.
Ronnett et al. first described a widely accepted and useful definition of PMP into three pathological subtypes with different pathological characteristics and different prognoses: disseminated peritoneal adenomucinosis (DPAM) which remains potentially non-invasive and

Abstract
Pseudomyxoma peritonei (PMP) is a rare complication of mucinous tumours of appendiceal or ovarian origin that results in peritoneal and omental implants.Clinical morbidity and mortality arise from the fact that copious amounts of extracellular and peritoneal mucin result in distortion and loss of function of visceral organs.Therapeutic paracentesis is not possible because of the nature of the mucin.Currently, new techniques are being used to attempt to debulk the mucin volume; none, however, has lead to superior outcome.

Fig. 1. Multiple complex cystic masses of fat density in the peritoneum (1a), and characteristic scalloping of the liver and spleen margins (1b).
stays localised to the abdomen; peritoneal mucinous carcinomatosis (PMCA) which has a metastatic potential; and an intermediate subtype (PMCA-I) which has invasive and metastatic potential with the possibilities of liver, lung and lymph node metastases. 4ecent research indicates that the PMP clinical symptoms may be caused by an overwhelming production in mucin 2 protein (MUC2) secreting cells, as well as the fact that the excessively produced mucin has no place to drain; this raises the possibility of MUC2-targeted therapy. 5

Imaging findings
4][5][6][7][8][9] Ultrasound often reveals gross, non-mobile ascites with septations and echogenicity.When correlated clinically, these radiologic features are highly specific for PMP.In patients with incidental findings of PMP, plain films of the abdomen may reveal abdominal calcific plaques, ascites and poorly-defined soft-tissue masses.These plain-film findings should be followed by CT studies. 6CT can also be used to follow-up and re-evaluate patients.

Treatment
Although therapeutic paracentesis is not possible because of the nature of the mucin, enough material can be removed by ultrasound guidance for diagnostic evaluation, if the diagnosis is not certain.This is rarely required as the history, examination, and imaging studies often lead to the diagnosis. 1urrently, cytoreductive surgery combined with peri-operative intraperitoneal chemotherapy is the standard treatment for patients with peritoneal spread of primary appendiceal tumours.This is achieved by combining peritonectomy procedures with peri-operative intraperitoneal chemotherapy. 8PMP of ovarian origin is usually treated surgically by hysterectomy, bilateral salpingo-oophorectomy, prophylactic appendectomy, and general debulking of the mucin. 3

Differential diagnosis
The differential diagnosis includes primary or secondary peritoneal tumours, which may also present with scalloped liver margins and septated ascites. 10Pancreatitis with ascites and pancreatic pseudocysts may also form part of the differential diagnosis, although the presence of pancreatic abnormalities may allude to this diagnosis.Infective causes such as pyogenic peritonitis, widespread echinococcal disease and TB peritonitis, may be considered but the clinical presentation of these patients as well as the presence of other imaging findings such as liver abscesses or micro-abscesses (in the case of TB) may also be present.

Figs 2 a
Figs 2 a and 2b.Compression of varying degrees of the visceral organs and structures.