Intramuscular Lipoma in Thenar or Hypothenar Muscle

Journal of the Korean Society for Surgery of the Hand 2002;7(2):193-199.
Published online June 1, 2002.

Young Ho Lee, Byung Heum Kim, Jun Mo Jung, Moon Sang Chung, Goo Hyun Baek

무지구근 또는 소지구근에 발생한 근육내 지방종

이영호, 김병흠, 정준모, 정문상, 백구현

Abstract

Purpose
: Intramuscular lipoma occurred in hand is extremely rare. We experienced six cases of intramuscular lipoma in thenar or hypothenar muscle, and analyzed their clinical features. Materials and Methods : Four of them occurred in thenar muscle, and two in hypothenar. Their mean age was 49 years. Preoperative MRI was taken in all patients. All the operations were performed under loupes magnification. Results : Four patients with thenar lipoma had difficulty in moving their thumbs. Two out of four patients with lipoma in the thenar muscles, had intermittent paresthesia and hyperesthesia caused by compression of the radial digital nerve of the thumb. Two patients with lipoma in the hypothenar eminence complained of difficulty in strong grip. The average diameter of the thenar group in its longest dimension was 5.2 cm, of the hypothenar group 5.5 cm. During the mean follow-up of 49 months, no tumor recurred. Conclusion : In our series, four cases were well-circumscribed intramuscular lipomas. Well-circumscribed type was more common than infiltrative type. MRI was very helpful to differentiate both types as well as to differentiate lipoma from other tumors of the hand. Dissection of the tumor under loupes magnification may contribute to decrease the recurrence rate.