Nodular lesions are larger and deeper than macules and papules, mostly invading deeper down into the dermis and reaching the subcutaneous tissue in severe cases. The surface is semicircular and smooth. The surface of inflammatory nodules is red, painful and angular, with a diameter of 0.5 to 5 cm. late nodules often break down, such as late syphilis nodular lesions, skin tuberculosis nodules are ulcerated and scarred. The nodules have deeper histopathological changes mostly in the deep dermis and can invade the subcutaneous fat layer, so they can be accompanied by lipid membrane and vascular type changes. The emetic has a slight pathological change in the superficial dermis, which differs from the spotted rash and papule pathological changes in the epidermis and superficial dermis. Depending on the etiology, nodules can be limited, asymmetrical, and few in number; they can also be systemic, symmetrical, and few or sparse in number. Nodular dermatoses generally have mild acute systemic symptoms, slow onset and relatively long course, such as cutaneous tuberculosis, syphilis, and erythema nodosum chronic migrans. Therefore, they are clinically different from maculopapular and papular skin diseases. Nodules are classified as inflammatory or non-inflammatory. How to diagnose implantation nodules? 1.Extractable nuclear antigen (ENA) Extractable nuclear antigen is mainly anti-ribonucleoprotein (RNP) antibody and anti-Sm antibody. Rheumatoid factor (RF) Rheumatoid factor is an autoantibody against human degenerative immunoglobulin that appears in the serum of patients with rheumatoid arthritis and other diseases. 3, plasma cavity fluid cell count The cell count is to determine the number of cells in the fluid. The microscopic counting method and the specimen dilution method are generally used. The direct counting method is suitable for clear appearance and cell count. Calcitonin (CT) Calcitonin is a peptide hormone synthesized and secreted by parafollicular cells of thyroxine, which can reduce the concentration of calcium and phosphorus in plasma and inhibit the absorption of calcium and phosphorus. Multiple thyroid nodules are a type of thyroid nodule. Thyroid nodules are a very common condition, especially in middle-aged women. Thyroid nodules are divided into two categories: benign and malignant, with benign nodules accounting for the majority of cases and less than 1% of malignant nodules. A variety of clinical thyroid disorders, such as thyroid degeneration, inflammation, autoimmunity, and neoplasia, can manifest as nodules. Thyroid nodules can be solitary or multiple, with multiple nodules having a higher incidence than solitary nodules, but solitary nodules have a higher incidence of thyroid cancer.