Table 1.

Summary table for retroperitoneal lipomatosis.

Etiology	Sporadic development of non-encapsulated lipomas in retroperitoneum. Associated with multiple symmetric lipomatosis.
Incidence	1.7 cases per 100,000 population.
Gender ratio	Male to female ratio is 18:1.
Age predilection	4th to 5th decade
Risk factor	Black race
Treatment	Conservative and follow-up in mild or asymptomatic cases. Surgical excision with or without urinary tract interventions (stenting, ureterostomy).
Prognosis	Progressive and non-curable nature of disease causing varying degree of urinary tract obstruction eventually leading to end stage renal disease if not treated. Patients subjected to excision with or without urinary diversion lead symptom free life. Life time risk of urinary bladder malignancy.
Imaging findings
Plain Radiographs	Extensive lucent areas in abdomen and pelvis.
Sonography	Diffuse hyperechoic mass causing sleeve like encasement of retroperitoneal organs along with their displacement and cigar shaped elongated and floating bladder in pelvis.
Intravenous urography	Varying degree of hydronephrosis and hydroureter. Urinary bladder is elongated in shape.
Barium enema	Elongated, straightened rectum with enlarged pre sacral space.
CT scan	Non enhancing fat density diffuse mass in retroperitoneum with few fibrous septations within it.
MRI scan	Homogenously hyperintense retroperitoneal lesion on both T1W and T2W sequences and showing suppression of signal on fat saturated sequences. No enhancement on post contrast images.