a 80-year - old man presented with a recent onset of constipation , anal discomfort , and anal incontinence .
several months ago , he experienced a sensation of something passing through the anus at defecation , that he manually reinserted , accompanied by tenesmus and rectal bleeding , for which he had a diagnosis of  hemorrhoids  .
these symptoms worsened in the following months , since the mass began to prolapse independently of defecation , became painful when standing or walking , made defecation obstructed , and caused anal incontinence , for which he was referred with a presumptive diagnosis of neoplasia .  
inspection of anal region revealed a large , soft , ulcerated mass protruding through the anus that was suspected for a submucosal neoplasia .
, the mass was pulled through the anal canal , and it was noted that it arises in the posterior wall of the rectum , 3 centimetres above the dentate line , where it developed a pseudostalk , presumably as a result of the repeated prolapses .
lipomas of the large intestine are relatively uncommon in clinical practice , although they are considered to be the benign tumours that occur most frequently , adenomas excluded , and the commonest nonepithelial tumours .
some authors have reported a female predominance while others found a nearly equal sex incidence . in general , most lipomas are silent , and most series in the literature are autoptic reports in which their incidence ranges from 0.35 to 4.4% .  
the number of large bowel lipomas found incidentally at necropsy far exceed the number of surgically treated cases .
the symptomatic lipomas are of clinical importance because of the many diagnostic and therapeutic problems they may cause .
clinical signs are reported in a poor percentage of patients and are related to tumour location and size .  
symptoms , that include bleeding , constipation , changing bowel habits , abdominal pain , intestinal obstruction , or intussusception of the mass [ 37 ] , are more common when the lipoma is greater than 2  cm in diameter .
lesions are sessile or polypoid and are submucosal , in about 90% of cases , or subserosal . in size , the tumours range from a few millimetres to several centimetres ( 0.58  cm in the serie of castro and stearns ; 421 in that of michowitz et al . ; 0.510 in that of rogy et al . ) . in some percentage ,
the lipomas are two or more ( 24.4% )   and not rarely associated with other pathologies , namely , colorectal cancer .
anyway , the high incidence of this association in some reports ( 33.3% )   does not reflect the actual incidence in the general population , but it reflects that of a cancer - patient population .
the most common site of origin is the right colon [ 3 , 9 ] .
there is no explanation for the predilection of lipomas of the large bowel to occur in the right side .
lipomas of the rectum are quite rare , and , in the various studies , are reported in a small number of patients . in the serie of castro and stearns ,
only 5 out of 45 lipomas of the large bowel ( 11.1% ) were in the rectum and only one of these was palpable .
the size of the lipomas of the rectum was recorded in 4 cases : 3 were less than 2  cm , and one was 24  cm in diameter .
haller and roberts reviewed 29 lipomas of the large bowel in 20 patients , none of which was in the rectum .
, found only one lipoma of the rectosigmoid ( 4.54% ) in his series of 22 cases .
in an 18-year study , rogy et al . reported 17 patients with lipomas of the large bowel , and only three out of 21 were in the rectum .
reported 11 patients with large bowel lipomas , all located proximal to the sigmoid colon .  
the prolapse of a rectal lipoma through the anus is a rare event , and a few cases are reported in the literature [ 13 , 14 ] .  
taylor and wolff , in a review of the mayo clinic experience of 91 surgically managed colonic lipomas from 1976 to 1985 , report no rectal location .
ryan et al . , in a review of the surgical pathology files , over a 50-year period , found 13 cases of colonic lipomas , none of these were in the rectum .
identified 5 patients with symptomatic lipoma of the large bowel , searching the computerized histopathologic records of the leicester   general hospital and leicester royal infirmary , in a 11-year period , located , respectively in proximal colon ( 2 ) , sigmoid colon ( 2 ) , and rectum ( 1 ) .
the patient with the rectal lipoma was a 35-year - old female presented as an emergency with lower abdominal pain and prolapsed rectal polyp , 6 centimetres in diameter ( see figures 1 and 2 ) . in a review of 11 patients treated for symptomatic lipomas of the gastrointestinal tract , during the period 19661972 , ackerman and chughtai found the tumour located in the stomach ( 3 cases ) , in the ileocaecal region ( 4 ) , and in the colon ( 3 ) ; the more distal lipoma was found in the sigmoid colon .
 submucosal lipomas of the large bowel are uncommon . 
 occasionally , they occur in the rectum and may cause aspecific symptoms ; presentation with rectal prolapse is very unusual and may lead to a misdiagnosis of simple mucosal prolapse . 
 the paper describes an additional case of a prolapsing rectal mass that led to diagnosis and surgical treatment of a rectal lipoma under local anesthesia . 
1. Case Report
2. Discussion