An extraosseous aneurysmal cyst in the pelvic cavity: report of a case

A 51-year-old Japanese female was referred to us with a left lower quadrant pain and palpable mass. The CT and MRI study showed a 10 x 8 x 8 cm of wel l-circumscribed, multicystic mass adjacent to the left iliac bone. The mass was excised and consisted of multiple cysts containing bloody viscous mate rial surrounded by thin-ring of eggshell-like tissue. The histological find ings correlated with those of an aneurysmal bone cyst. This extraosseous ca se might be the first reported case observed in the pelvic cavity. (C) 2000 Elsevier Science Inc. All rights reserved.