Blood, hematopoietic organs – immune system (D50-D90).
- Sarcoidosis (synonyms: Boeck’s disease; Schaumann-Besnier’s disease) – systemic disease of connective tissue with granuloma formation.
Skin and subcutaneous (L00-L99).
- Acne nodulocystica – form of acne characterized by the appearance of nodules and cysts.
- Epidermal cyst – bulging elastic node in the area of the epidermis.
- Erythema nodosum (nodular rose)
- Histiocytoma (synonyms: nodulus cutaneus, dermatofibroma lenticulare) – benign (benign) reactive fibroblast (main cells of connective tissue) resembling hard fibroma. It is also called dermatofibroma.
- Vasculitis nodularis – vascular wall inflammation of vessels in the deep cutis/fatty tissue.
Infectious and parasitic diseases (A00-B99).
- Actinomycosis – infection with actinomycetes (ray fungus).
- Leprosy
- Lupus vulgaris – chronic skin tuberculosis.
- Swimming pool granuloma
- Syphilis (Lues)
- Verruca (wart)
Musculoskeletal system and connective tissue (M00-M99)
- Gouty tophi (sodium urattophi) – nodular thickening of cartilaginous tissue within or near affected joints.
- Heberden’s nodes – growths as bone/cartilage localized on the extensor sides of the finger end links.
- Polyarteritis nodosa – the classic form of polyarteritis nodosa (PAN) is a severe generalized disease (weight loss, fever, night sweats/nocturnal sweating, “chlorotic marasmus”) that is either insidious or post or parainfectious and is associated with systemic vasculitis.
- Rheumatoid nodules (noduli rheumatici), subcutaneous (located under the skin), coarse, shifting nodules); develop in 20 to 30 percent of patients with rheumatoid arthritis
Neoplasms – tumor diseases (C00-D48).
- Basal cell carcinoma (BCC; basal cell carcinoma
- Dermatofibroma (histiocytoma) – benign (benign) neoplasm consisting of connective tissue of the dermis (liver skin).
- Fibromas
- Granuloma pyogenicum – hemangioma (blood sponge) originating from vessels of the capillary body.
- Keratoacanthoma – benign (benign) epithelial proliferation with central horny plug.
- Lipoma (fatty tumor)
- Lymphoma (cancer of the lymph nodes)
- Malignant melanoma (black skin cancer)
- Merkel cell carcinoma – caused by Merkel cell polyoma virus (MCPyV or incorrectly MCV); fast-growing, solitary, cutaneous (“belonging to the skin”) or subcutaneous (“under the skin”) tumor; clinical presentation: red to bluish-purple nodus that is asymptomatic
- Metastases (daughter tumors).
- Squamous cell carcinoma – malignant neoplasm of skin / mucosa.
Ears – mastoid process (H60-H95)
- Chondrodermatitis nodularis chronica helicis – up to pea-sized nodules with a wall-like edge on the auricle, occurring mainly in older men, which may enclose a horn cone
Other causes
- Amyloid and calcium deposits
- Xanthoma – skin lesion resulting from increased storage of plasma lipoproteins in the skin in the context of hyperlipoproteinemias.
