わっ、こんなのがお腹に・・・

Images in Clinical Medicine

Rachael Sussman, M.D., and Jonah Murdock, M.D., Ph.D.

N Engl J Med 2015; 372:1359  April 2, 2015

Peritoneal Loose Body

ちょっとお腹が凄いことになっている。主訴は頻尿でしょうか？

小生の友人A君は若い頃、食後お腹がいっぱいになると必ずトイレ通いが始まった。小さい方である。この写真の左上のように膀胱を圧排するのである。当時の流行言葉で「胃下垂」なのであった（今頃こんな言葉は使わない）

ちなみにこのダチョウの卵のようなしろもの、ほとんど無構造であるらしい。

こんなのが出来て、自由に腹腔内を動いているのですから・・・

A 62-year-old man presented for evaluation of a history of urinary frequency of more than 20 years. The physical examination and laboratory findings were unremarkable. Computed tomography of the abdomen and pelvis revealed an 8.5-cm midline mass with central calcification (Panel A, red arrow) superior to and compressing the bladder (Panel A, blue arrow). Laparoscopy revealed a free-floating, smooth, firm, rubbery mass measuring 10 cm by 9.5 cm by 7.5 cm and weighing 220 g (Panels B and C). The sectioned specimen included several layers; green ink was used to delineate section margins (Panel D). Histologically, the mass contained predominantly acellular, laminated, fibrous tissue; centrally, the specimen contained proteinaceous material with fibrinoid necrosis, surrounded by a ring of calcification. The findings were consistent with a peritoneal loose body, a formation that is thought to result from torsed, infarcted, and detached epiploic appendages that transform into fibrotic masses. Such masses are often asymptomatic when they are small, but they can be large enough to cause extrinsic compression that is associated with bowel obstruction, urinary retention, or (as in this patient) urinary frequency. The patient's urinary frequency resolved immediately after the surgical removal of the mass.