Subtrochlear lymph node shadow 13mm is not necessarily cancer, but the cause of enlarged lymph node may also be caused by inflammation and so on. The normal size of lymph nodes under tracheal eminence should be 2 to 5mm, and the shadow of 13mm lymph nodes under tracheal eminence may be caused by inflammation, such as upper respiratory tract infection, pharyngitis, or rheumatic immune disease, which may not necessarily be cancer. If malignant tumor is suspected, relevant examinations such as chest CT enhancement and ultrasound-guided lymph node biopsy should be performed to clarify the nature of the lymph nodes. Patients should seek medical treatment as early as possible to clarify the cause of the disease. If it is caused by inflammation, anti-inflammatory treatment should be given; if it is a malignant disease, it should be treated as early as possible to improve the prognosis.