Nodule (medicine)
Solid, non-blisterform elevated areas in or under the skin
From Wikipedia, the free encyclopedia
In medicine, a nodule is a small, discrete lump or growth that is different from surrounding tissue. They are often detected by medical imaging and can be either benign or malignant.[1]
Definitions vary by medical specialty. In dermatology, nodules are usually greater than 1 cm in diameter, in contrast to raised, soft bumps of less than 1 cm, which are termed papules, and to cysts, which contain fluid.[2] In pulmonology, when imaging the lungs by radiography, a nodule is a round, focal opacity in the lung tissue of less than 3 cm in diameter, with lesions larger than that instead termed masses.[3] In endocrinology, a thyroid nodule is a lump formed by abnormal growth.[4]
The evaluation of a skin nodule includes a description of its appearance, its location, how it feels to touch and any associated symptoms which may give clues to an underlying medical condition.[5]
Nodules in skin include dermatofibroma[6] and pyogenic granuloma.[7] Nodules may form on tendons and muscles in response to injury,[8] and are frequently found on vocal cords.[9] They may occur in organs such as the lung,[10] or thyroid,[11] or be a sign in other medical conditions such as rheumatoid arthritis.[12]
Characteristics
Evaluation
The evaluation of a skin nodule includes a description of its appearance, its location, how it feels to touch and any associated symptoms which may give clues to an underlying medical condition.[5]
Often discovered unintentionally on a chest x-ray, a single nodule in the lung requires assessment to exclude cancer.[10]
Conditions
Nodules may form on tendons and muscles in response to injury,[8] and are frequently found on vocal cords.[9] They occur in conditions including endometriosis,[14] neurofibromatosis,[7] and in rheumatoid arthritis.[12] They may also feature in Kaposi's sarcoma[15] and gonorrhea.[16]
