Irritative voiding symptoms and microscopic hematuria caused by intraperitoneal calcified fat necrosis

A previously healthy 60-year-old man presented with urinary urgency and microhematuria. The workup revealed no urothelial lesions, but did suggest a calcified intraperitoneal mass causing extrinsic compression of the bladder. Laparoscopic exploration revealed a glistening, spherical mass attached by a stalk to the sigmoid colon. Removal and histologic examination of the mass revealed calcified fat necrosis, most likely due to the spontaneous torsion and calcification of an appendix epiploicae. The patient's symptoms and microhematuria resolved after removal. This case represents an unusual occurrence of irritative voiding symptoms probably due to the extrinsic compression of the bladder by a mass of membranous fat necrosis.