[objective] To explore the anatomy and function of the palmar cutaneous branch of the median nerve（PCBNN）[methods] A 52-year-old woman presenting with previous rupture of the palmaris longus tendon. [results] During surgery, we found that the end of the tendon had formed nodules. After removing the nodules, the PCBMN was released, and half a year later, the abnormal feelings had disappeared. [conclusion] We aim to remind surgeons of this type of compression and to highlight the importance of maintaining vigilance in order to avoid nerve injury.