Thigh numbness after inguinal lymph node dissection may be due to injury to nerves, such as the femoral nerve and its anterior cutaneous branch, during the dissection process. After emanating from the lateral border of the psoas major muscle, the femoral nerve descends between the psoas major muscle and the iliacus muscle to the inguinal region, and then penetrates from the deep surface into the femoral triangle region slightly lateral to the midpoint of the inguinal ligament, and its anterior cutaneous distributes in the skin of the middle and lower part of the front of the thigh, which is susceptible to skin sensory disorders of the front of the thigh and the medial side of the calf after damage. Inguinal lymph node dissection is a large area of dissection, easy to cause damage to the anterior cutaneous branch of the femoral nerve, prone to postoperative numbness in the thigh, if this phenomenon occurs, please consult a doctor in time, through a professional doctor to carry out reasonable and standardized diagnosis and treatment.