Makoto NIIZAWA¹, Hideaki ISHIDA^{1, 2}, Tomoya KOMATSUDA^{1, 2}, Tsukasa YOSHIDA¹, Toshio NAGANUMA¹, Akira ZENIYA¹, Tomoyuki KURAMITSU¹, Osamu MASAMUNE²

¹Second Division of Internal Medicine, Akita City Hospital, ²First Department of Internal Medicine, Akita University School of Medicine

キーワード : CT, Psoas, Schwannoma, Ultrasound, Ultrasonic transcutaneous measurement

We report a case of asymptomatic schwannoma of the right psoas muscle, incidentally detected by ultrasound (US). Sonographically, the lesion was composed of a central cystic area and a surrounded by a solid layer corresponding to the macroscopic findings. Although schwannoma is a rare disease, the possibility of schwannoma must be kept in mind when US detects a round mass containing a central cystic area.