A hard lump in the penile coronal groove may be caused by penile cavernous sclerosis, surgical scarring, penile sclerosing lymphadenitis and other causes. 1. penile cavernous sclerosis: due to chronic injury, inflammation, hypertension, genetic inheritance and other factors, resulting in penile cavernous leukomalacia fibrotic lesions, which can be manifested in the penile coronal groove with a painless, itchy and able to slide a long hard lump. 2. Surgical scar: after circumcision, local tissue granulation hyperplasia, there may be a ring-shaped surgical incision scar at the level of the coronal groove, which is mainly manifested as centipede-like strip hard lumps. 3. Penile sclerosing lymphangitis: due to infection and trauma to the penile lymphatic vessels, blockage and inflammatory exudation may lead to localized lymphatic stiffness and protrusion. It usually manifests itself as a striated or nodular stiffness under the skin at the back of the penis or in the coronal groove. A hard lump in the coronal groove of the penis may also be due to other causes, and patients are advised to consult a doctor for timely examination to clarify the cause of the disease and follow the doctor’s instructions for treatment.