手和前臂的手指屈肌腱的非外伤性皮下断裂很少见。手指屈肌腱闭合性和皮下断裂的大多数部位是腱骨附着点和肌腱交界处，腱内病变并不常见。我们报告一例76岁女性的病例，她来我们科室就诊，有一个月的软组织肿块病史，左中指屈曲受限，无外伤。术前磁共振成像显示软组织肿块导致手指屈曲受限。术中发现，中节指骨深屈肌腱腱内断裂；切除病变以平滑磨削肌腱。术后一年，软组织肿块和手指屈曲受限得到缓解，没有复发。版权所有 © 2024，Yano 等人。

Atraumatic subcutaneous rupture of the finger flexor tendon of the hand and forearm is rare. Most sites of closed and subcutaneous ruptures of the finger flexor tendon are the tendon-bone insertion and musculotendinous junction, and an intratendinous lesion is unusual. We report the case of a 76-year-old female who presented to our department with a one-month history of a soft tissue mass and limited flexion of the left middle finger without trauma. Preoperative magnetic resonance imaging revealed a soft tissue mass that caused limited finger flexion. Intraoperative findings showed an intratendinous rupture of the flexor digitorum profundus tendon at the middle phalanx; the lesion was resected to obtain smooth grinding of the tendon. One year postoperatively, the soft tissue mass and limited flexion of the finger resolved without recurrence.Copyright © 2024, Yano et al.