Severe rectal prolapse and solitary rectal ulcer in a young anorectic woman with myxoid degeneration of visceral adipose tissue.

Rectal prolapse is a disorder in which the rectum protrudes from the anal canal. Solitary rectal ulcer may coexist. Both conditions have been associated with chronic constipation and excessive straining during defecation. Rectal prolapse has been rarely reported in women suffering from anorexia nervosa. Lack of rectal support because of loss of ischiorectal fat has been proposed as one of the possible mechanisms in this condition, together with chronic constipation and abuse of laxative. We report the case of an anorexic woman with a severe rectal prolapse and bleeding requiring urgent Altmeier's procedure. Surgery was complicated by dehiscence of the anastomosis and volvulus, requiring ileostomy and laciniae debridement. Pathological analysis of all the surgical samples taken from different abdominal sites highlighted changes in the visceral adipose tissue consisting in nodular aggregates of small adipocytes dispersed in a myxoid matrix surrounding blood vessels within abundant fibrosis. The morphologic features resemble those observed in primordial fetal fat and are comparable to those observed in cancer associated cachexia. The diffuse myxoid degeneration of visceral adipose tissue may play a role in the pathogenesis of rectal prolapse in patients with anorexia nervosa. Besides starvation, the mechanism sustaining myxoid degeneration of the adipose tissue is not entirely clear. Whenever possible improving nutritional and clinical conditions should be ideal before any surgical approach.