granuloma [gran″u-lo´mah] (pl. granulomas, granulo´mata)
an imprecise term applied to (1) any small nodular, delimited aggregation of mononuclear inflammatory cells, or (2) a similar collection of modified macrophages resembling epithelial cells, usually surrounded by a rim of lymphocytes, often with multinucleated giant cells. Some granulomas contain eosinophils and plasma cells, and fibrosis is commonly seen around the lesion. Granuloma formation represents a chronic inflammatory response
initiated by various infectious and noninfectious agents.
apical granuloma modified granulation tissue containing elements of chronic inflammation located adjacent to the root apex of a tooth with infected necrotic pulp.
an annular lesion seen on skin chronically exposed to the sun, with a raised border and a center that appears normal but is actually elastotic
benign granuloma of thyroid chronic inflammation of the thyroid gland, converting it into a bulky tumor that later becomes extremely hard.
dental granuloma one usually surrounded by a fibrous sac continuous with the periodontal ligament and attached to the root apex of a tooth.
2. a disorder similar to eosinophilic gastroenteritis, characterized by localized nodular or pedunculated lesions of the submucosa and muscle walls, especially of the pyloric area of the stomach, caused by infiltration of eosinophils, but without peripheral eosinophilia and allergic symptoms.
granuloma fissura´tum a firm, whitish, fissured, fibrotic granuloma of the gum and buccal mucosa, occurring on an edentulous alveolar ridge and between the ridge and the cheek.
foreign-body granuloma a localized histiocytic reaction to a foreign body in the tissue.
giant cell reparative granuloma, central a lesion of the jaws composed of a spindle cell stroma punctuated by multinucleate giant cells, considered by most to be a central lesion of the bone of the jaws, presenting an inflammatory reaction to injury or hemorrhage. Some, however, consider it to be a giant cell tumor occurring in both benign and malignant forms, and others consider it to be a form of osteogenic sarcoma, varying in degree of malignancy.
a granulomatous disease that is associated with uncleanliness and is caused by the microorganism Calymmatobacterium granulomatis
(sometimes called a Donovan body
). Called also granuloma venereum
. Although granuloma inguinale is often considered to be a venereal disease, research does not support the hypothesis that it is transmitted by sexual contact. It is possible that natural resistance to the disease is high, so that only a few of the persons exposed are affected. About 10 days to 3 months may elapse after exposure until appearance of the first symptoms, usually small painless ulcers that bleed easily. Swelling in the groin may then follow. A new ulcer or ulcers may appear as the old one heals, so that granuloma inguinale may eventually cover the reproductive organs, buttocks, and lower abdomen, with extensive sores and a foul odor. As persons who have the disease seem to develop little immunity to it, granuloma inguinale can be present for many years.
Treatment of the disease may be with streptomycin. tetracyclines, or lincomycin. There is no known preventive for granuloma inguinale, although it is rare where sanitary living conditions prevail. The drainage from lesions may be infectious and handwashing and basic cleanliness are required. The Centers for Disease Control and Prevention recommends standard precautions
lipophagic granuloma a granuloma attended by the loss of subcutaneous fat.
midline granuloma a rare disease of unknown etiology, characterized by granulomatous lesions of the nasal mucosa, sinuses, palate, and pharynx. Massive, progressive, erosive lesions that destroy the involved soft tissue, cartilage, and bone and sometimes extend to the brain are typical. Untreated cases are fatal (lethal midline granuloma).
pyogenic granuloma a benign, solitary nodule resembling granulation tissue, found anywhere on the body, commonly intraorally, usually at the site of trauma as a response of the tissues to a nonspecific infection.
the granuloma seen with sarcoidosis
, consisting of multinucleated giant cells surrounded by macrophages and epithelioid cells derived from macrophages.
swimming pool granuloma a chronic granulomatous bacterial infection caused by contamination of an abrasion sustained in a swimming pool by Mycobacterium marinum, which histologically and clinically resembles tuberculosis. It tends to heal spontaneously within a few months to 2 years.
granuloma telangiecta´ticum a form characterized by numerous dilated blood vessels.
a form of tinea corporis
seen mainly on the lower legs, due to infection of hairs by the fungus Trichophyton
; characteristics include raised, circumscribed, boggy granulomas that are disseminated or arranged in chains. Lesions are slowly absorbed or undergo necrosis, leaving depressed scars. Called also Majocchi's granuloma
granuloma tro´picum yaws
granuloma (gran?yu-lo'ma ) (gran?yu-lo'ma-ta) plural.granulomasplural.granulomata [ granulo- + -oma]
An inflammatory response that results when macrophages are unable to destroy foreign substances that have entered or invaded body tissues. Large numbers of macrophages are drawn to the affected area over 7 to 10 days, surround the target, and enclose it. They in turn are surrounded by polymorphonuclear leukocytes, other immune cells, and fibroblasts. Granulomas are common in many conditions, including leprosy, tuberculosis, cat scratch disease, some fungal infections, and foreign body reactions, e.g., reactions to sutures. granulomatous
See: giant cell
; Wegener granulomatosis
A circular rash with a raised red border, usually found on the hands, knuckles, or arms of young patients. The cause is unknown. The rash often lasts 1 or 2 years and then may disappear spontaneously. See: illustration
apical granulomaDental granuloma.
benign granuloma of the thyroid
A lymphadenoma of the thyroid.
A chronic, generalized granuloma caused by the fungus Coccidioides immitis. See: coccidioidomycosis
A granuloma developing at the tip of a tooth root, usually the result of pulpitis. It consists of a proliferating mass of chronic inflammatory tissue and possibly epithelial nests or colonies of bacteria. It may be encapsulated by fibrous tissue of the periodontal ligament. Synonym: apical granuloma; apical periodontitis
A form of xanthomatosis accompanied by eosinophilia and the formation of cysts on bone.
A circumscribed, firm, fissured, fibrotic, benign tumor caused by chronic irritation. It may occur where hard objects such as dentures or the earpieces of glasses rub against the labioalveolar fold or the retroauricular fold. The tumor disappears when the irritating object is removed.
foreign body granuloma
Chronic inflammation around foreign bodies such as sutures, talc, splinters, or gravel. Synonym: foreign body reaction
granuloma fungoidesMycosis fungoides.
Any infectious disease in which granulomas are formed, e.g., tuberculosis or syphilis. Granulomas are also formed in mycoses and protozoan infections.
A granulomatous ulcerative disease in which the initial lesion commonly appears in the genital area as a painless nodule.
This type of granuloma is caused by a short, gram-negative bacillus, Calymmatobacterium granulomatis, (“Donovan body”).
Erythromycin, trimethoprim-sulfamethoxazole, or tetracyclines are used in treating this disease. Single-dose therapy with intramuscular ceftriaxone or oral ciprofloxacin may be effective.
A granuloma that develops on the iris.
A granuloma that contains fatty tissue or cholesterol.
A granuloma in which the macrophages have phagocytosed the surrounding fat cells.
Majocchi granulomaMajocchi disease.
malignant granulomaHodgkin disease.
pyogenic granuloma See: lobular capillary hemangioma
granuloma pyogenicum See: lobular capillary hemangioma
pyrogenic granuloma See: lobular capillary hemangioma
swimming pool granuloma
A chronic skin infection caused by Mycobacterium marinum.
A very vascular granuloma at any site, but esp. in the nasal mucosa or pharynx.
trichophytic granulomaMajocchi disease.
a tumor-like mass or nodule of granulation tissue, with actively growing fibroblasts and capillary buds, consisting of a collection of modified macrophages resembling epithelial cells, surrounded by a rim of mononuclear cells, chiefly lymphocytes, and sometimes a center of giant multinucleate cells; it is due to a chronic inflammatory process associated with infectious disease or invasion by a foreign body.
see acral lick dermatitis.
modified granulation tissue containing elements of chronic inflammation located adjacent to the root apex of a tooth with infected necrotic pulp.
canine eosinophilic granuloma coccidioidal granuloma
the secondary, progressive, chronic (granulomatous) stage of coccidioidomycosis.
one usually surrounded by a fibrous sac continuous with the periodontal ligament and attached to the root apex of a tooth.
a firm, whitish, fissured, fibrotic granuloma of the gum and buccal mucosa, occurring on an edentulous alveolar ridge and between the ridge and the cheek.
foreign body granuloma
a localized histiocytic reaction to a foreign body in the tissue.
idiopathic sterile g's
occur in dogs and cats; the lesions are painless and may become ulcerated and secondarily infected. An immune-mediated cause is suspected and the lesions often respond to treatment with corticosteroids or other immunomodulating drugs. Sometimes lesions regress spontaneously.
infection by one of the systemic mycotic fungal agents which result in a granulomatous lesion in the skin.
intestinal eosinophilic granuloma linear granuloma
well-delineated, elevated plaques with an eroded surface that occur in a linear pattern, usually on the caudal aspect of the hindleg(s) of cats. Pruritus is variable. Similar lesions may also occur in the oral cavity and on the lips. See also feline eosinophilic
a granuloma containing lipoid cells; xanthoma.
a granuloma attended by the loss of subcutaneous fat.
one characterized by the arrangement of histiocytes surrounding a focus of fibrin, foreign material, degenerating collagen.
peripheral giant cell reparative granuloma
a pedunculated or sessile lesion of the gingivae or alveolar ridge, apparently arising from the periodontium or mucoperiosteum, and usually due to trauma. It is uncommon in humans and animals. Called also reparative granuloma of the jaw.
a benign, solitary, nodule resembling granulation tissue, found anywhere on the body, commonly intraorally, usually at the site of trauma as a response of the tissues to a nonspecific infection.
reparative granuloma of the jaw
see peripheral giant cell reparative granuloma (above).
granuloma of the epididymis caused by leakage of spermatozoa from the efferent tubules or the epididymis into surrounding tissue. May be due to trauma, infection or to congenital defects in the duct system.
a large mass containing small abscesses, found in the wall of the uterus of the sow. See also botryomycosis
a form characterized by numerous dilated blood vessels.
the lesion of tuberculosis and the prototype of granulomatous inflammation. It is composed of histiocytes and epithelioid cells surrounded by giant cells of the Langhans type, lymphocytes and fibroblasts. Bacteria are found in the cytoplasm of the epithelioid and giant cells.
ulcerative granuloma of swine venereal granuloma
see canine transmissible venereal