Sonographic Appearance of Idiopathic Hypertrophy of the First Dorsal Interosseous Muscle of the Hand.

Yang,  Woo Jin; Lee,  Ka Eun; Jin,  Wook; Park,  So Young; Hwang,  Su Yeon; Park,  Ji Seon; Ryu,  Kyung Nam

Journal of Korean Society of Ultrasound in Medicine 2013;32(3): 193-197.

Woo Jin Yang, Ka Eun Lee, Wook Jin, So Young Park, Su Yeon Hwang, Ji Seon Park, Kyung Nam Ryu

¹Department of Radiology, Kyung Hee University Hospital at Gangdong, College of Medicine, Kyung Hee University, Seoul, Korea. jinooki@daum.net
²Department of Radiology, Kyung Hee University Hospital, College of Medicine, Kyung Hee University, Seoul, Korea.

Published online: September 30, 2013.

ABSTRACT

We present a rare case of a 28-year-old man with a non-tender soft tissue enlargement on the dorsal side of the first web space of the right hand. Sonographic evaluation showed thickening of the dorsal thenar muscle (dorsal interosseous muscle) without a mass-like or cystic lesion, as compared with the left dorsal thenar muscle. On grasping position, this finding was more prominent and no significantly increased vascular flow was observed in this muscle. We were able to diagnose idiopathic hypertrophy of the first dorsal interosseous muscle solely by sonography. Ultrasonographic evaluation is a noninvasive and accessible tool for diagnosis of pseudotumors, such as idiopathic thenar muscle hypertrophy.

Keywords: Ultrasonography; Thenar muscle; Pseudotumor; Hypertrophy