A sinuous hard lump on the dorsum of the penis at the corona may be present in sclerosing lymphangitis of the penis, cavernous sclerosis of the penis, and angioedema of the prepuce. 1. Sclerosing lymphangitis of the penis: the incidence is relatively low, and the cause of the lesion is not clear. Some patients may not have too obvious clinical symptoms, incidentally found in the dorsal coronal groove of the penis in the sinuous hard lump. Some patients may have localized pain manifestations, especially painful symptoms after erection. 2. Penile cavernous sclerosis: hard knots or plaques formed due to chronic proliferation of collagen fibers between the cavernous bodies of the penis due to various reasons, resulting in corresponding clinical symptoms. In the acute stage of the lesion, the symptoms of penile pain are obvious, and with the development of the disease, the degree of pain can be slowly reduced. 3. Foreskin angioedema: there can also be a sinuous hard lump on the back of the penis at the coronal groove. In summary, if there is any discomfort, timely medical treatment.