Pelvic Lipomatosis Presenting as Chronic Constipation: The Challenges of Treatment

Introduction: Pelvic lipomatosis (PL) is a rare disease characterized by deposition of nonmalignant fat cells in the perivesical and perirectal area that typically leads to urinary obstruction. In refractory constipation, pelvic imaging should be obtained to rule out anatomic variants. We present a case of pelvic lipomatosis causing refractory constipation. Case Description: We describe a 41 year-old adopted Korean male who presented with a 4-year history of constipation. His stool ranged from brown pellets to pencil thin stools (Bristol type I-II). He reported 5 bowel movements daily without improvement despite supportive therapy. The patient made lifestyle modifications to include increased water and fiber intake, softeners, laxatives, food elimination, FODMAPs, IBS-C medications and bowel retraining. The patient denied any associated symptoms (abdominal pain, rectal pain, bloating, flatus, nausea, vomiting, mucus or blood in the stool). His workup was unremarkable for malignant, inflammatory, infectious, metabolic and endocrine markers (Table 1). The patient had a KUB, CT-AP, colonoscopy and flexible sigmoidoscopy with incidental findings that did not explain the cause of his constipation. His findings were addressed and treated with bilateral hernia repair, H. pylori triple eradication, TURPT and TURBT, however his constipation continued to persist. Anal manometry and balloon expulsion were pursued (Table 2) and ultimately with a suspicion of outlet obstruction a MRI of the pelvis demonstrated compression of the rectum by surrounding fat (Image 1). Tissue examination of the benign masses resected from the bladder and prostate provided further evidence to support the diagnosis of PL. The patient continued standard therapy for constipation with pelvic rehabilitation/biofeedback, however with only minimal improvement. Surgical consultation was obtained and the patient opted for perivesicular lipoma extirpation.Table: Table. Laboratory WorkupTable: Table. Anal Manometry and Balloon Expulsion ResultsFigure: T1 MRI shows the upper rectum being compressed by the surrounding hyperintense fat.Discussion: Pelvic lipomatosis is associated with high morbidity and poor quality of life. There should be a high clinical suspicion in patients who present with a simultaneous onset of constipation and urinary incontinence. To date, no formal guidelines for treatment exist. Salvage therapies to include surgery, radiation, steroids, and chemotherapy have not been proven to be effective. Urinary diversion may be required to prevent fulminant renal failure. This is a unique case of PL presenting with a primary chief complaint of constipation.