Medical Dictionary

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granuloma (gran-u-lo′ma)
Term applied to nodular inflammatory lesions, usually small or granular, firm, persistent, and containing compactly grouped modified phagocytes such as epithelioid cells, giant cells, and other macrophages. SEE ALSO: granulomatosis. [granulo- + G. -oma, tumor] actinic g. an annular eruption on sun-exposed skin which microscopically shows phagocytosis of dermal elastic fibers by giant cells and histiocytes. SYN: Miescher g.. amebic g. SYN: ameboma. g. annulare a chronic or recurrent, usually self-limited papular eruption that tends to develop on the distal portions of the extremities and over prominences, although the condition may be generalized; waxy papules tend to form annular lesions characterized microscopically by foci of dermal necrosis with mucin deposits, bordered by histiocytes with palisaded nuclei. apical g. SYN: periapical g.. beryllium g. a sarcoid-like granulomatous reaction to exposure to inhaled beryllium, or to skin cuts by fluorescent lamp glass. bilharzial g. SYN: schistosome g.. Capillaria g. granulomatous lesions found in the liver and lung are a tissue response at the site of eggs or worms. cholesterol g. g. with prominent clefts of cholesterol surrounded by foreign-body giant cells found in chronic otitis media and sinusitis. coccidioidal g. SYN: secondary coccidioidomycosis. cutaneous leishmaniasis g. lymphocytic granulomas with necrotic centers found during the healing process. dental g. SYN: periapical g.. Enterobius g. lesions containing dead worms and eggs of this nematode; have been found in vagina, cervix, fallopian tubes, omentum, peritoneum, liver, kidneys, and lungs. eosinophilic g. a form of Langerhans histiocytosis predominately involving the bones of young people; may be solitary or multiple; histologically composed of Langerhans cells and eosinophils. g. faciale persistent, well-demarcated, reddish-brown nodules of unknown cause that usually appear on the face in middle age and consist of a dense dermal infiltrate of eosinophils and neutrophils, separated from the epidermis and hair follicles, with fibrinoid vasculitis of unknown cause. fish-tank g. SYN: swimming pool g.. foreign body g. a g. caused by the presence of foreign particulate material in tissue, characterized by a histiocytic reaction with foreign body giant cells. g. gangrenescens SYN: lethal midline g.. giant cell g. a nonneoplastic lesion characterized by a proliferation of granulation tissue containing numerous multinucleated giant cells; it occurs on the gingiva and alveolar mucosa (occasionally on other soft tissues) where it presents as a soft red-blue hemorrhagic nodular swelling; it also occurs within the mandible or maxilla as a unilocular or multilocular radiolucency; microscopically similar lesions occur in the tubular bones of the hands and feet, are considered neoplastic, and may have a malignant course. Identical bony lesions may be seen in hyperparathyroidism and cherubism. SEE ALSO: giant cell tumor of bone. SYN: giant cell epulis, reparative giant cell g.. g. gravidarum a pyogenic g. developing on the gingiva during pregnancy; thought to be related to hormonally altered response of the oral mucous membranes to local irritants such as bacterial plaque on adjacent teeth. SYN: pregnancy tumor. infectious g. any granulomatous lesion known to be caused by a living agent; e.g., bacteria, fungi, helminths. g. inguinale a specific g., classified as a venereal disease and caused by Calymmatobacterium granulomatis observed in macrophages as Donovan bodies; the ulcerating granulomatous lesions occur in the inguinal regions and the genitalia; peripheral extension of the lesions produces extensive destruction. SYN: g. venereum. laryngeal g. a polypoid projection of granulomatous tissue into the lumen of the larynx, commonly following a traumatic tracheal intubation. lethal midline g. 1. destruction of the nasal septum, hard palate, lateral nasal walls, paranasal sinuses, skin of the face, orbit and nasopharynx by an inflammatory infiltrate with atypical lymphocytic and histiocytic cells; a form of lymphoma in most cases. 2. obsolete term for polymorphic reticulosis. SYN: g. gangrenescens, malignant g., midline malignant reticulosis g.. lipoid g. g. characterized by aggregates or accumulations of fairly large mononuclear phagocytes that contain lipid. lipophagic g. a lesion formed as a result of the inflammatory reaction provoked by foci of necrosis in subcutaneous fat, as in certain types of traumatic injury; the central focus of necrotic material is surrounded by an irregular zone of numerous macrophages, many of which become laden with tiny globules of lipid. lymphatic filariasis g. granulomatous lesion often found surrounding dead microfilariae. Majocchi granulomas inflammatory ringworm of the glabrous skin. SYN: tinea profunda. malignant g. SYN: lethal midline g.. Miescher g. SYN: actinic g.. g. multiforme a chronic granulomatous annular eruption of the skin on the upper body in older adults in central Africa; of unknown cause. ocular larva migrans g. eosinophilic granulomata found surrounding dead worms (generally, Toxocara spp.) in the eye; may mimic retinoblastoma. oily g. reaction to inclusion of a bulky, insoluble liquid (often an oily substance) which occurs several months, but sometimes years, after injection of the material. paracoccidioidal g. SYN: paracoccidioidomycosis. Paragonimus g. lesions caused by adult worms and eggs of the lung fluke trapped in the pulmonary parenchyma. periapical g. a proliferation of granulation tissue surrounding the apex of a nonvital tooth and arising in response to pulpal necrosis. SYN: apical g., dental g., root end g.. pulse g. SYN: giant cell hyaline angiopathy. pyogenic g., g. pyogenicum an acquired small rounded mass of highly vascular granulation tissue, frequently with an ulcerated surface, projecting from the skin, especially of the face, or oral mucosa; histologically, the mass is a lobular capillary hemangioma. SYN: lobular capillary hemangioma. reparative g. complication of stapedectomy in which a g. forms in the oval window around the prosthesis; it results in a sensory hearing loss. reparative giant cell g. SYN: giant cell g.. root end g. SYN: periapical g.. sarcoidal g. a non-necrotizing epithelioid cell g. similar to those seen in sarcoidosis. schistosome g. a granulomatous lesion formed around schistosome eggs embedded in tissues in cases of schistosomiasis (bilharziasis); typically these granulomata are found in intestinal tissues (Schistosoma japonicum or S. mansoni infection), bladder tissue (S. haematobium), and hepatic tissue (all human schistosomes). SYN: bilharzial g.. sea urchin g. granulomatous nodules, either foreign-body type or composed of epithelioid cells, from the retention of the spine of the sea urchin, occurring several months after the wounding of the skin. silica g. eruption of granulomatous lesions due to traumatic inoculation of the skin with sand, or materials that contain silica; this condition may follow dermabrasion using sandpaper technique. silicotic g. granulomatous nodule resulting from deposition of silica particles, usually occurring in lung. swimming pool g. a chronic, verrucous lesion most commonly seen on the knees; due to infection by Mycobacterium marinum. SYN: fish-tank g.. trichinosis g. lesions caused by cell death after penetration of migrating newborn nematode larvae. g. tropicum SYN: yaws. umbilical g. moist granulation tissue at the center of the umbilicus in neonates. g. venereum SYN: g. inguinale. zirconium g. g. from zirconium salts, usually occurring in the axillae, from antiperspirants containing this material, or from the application of hydrous zirconium oxide to poison ivy lesions.

granulomatosis (gran′u-lo-ma-to′sis)
Any condition characterized by multiple granulomas. allergic g. SYN: Churg-Strauss syndrome. lipid g., lipoid g. SYN: xanthomatosis. lymphomatoid g. angiocentric malignant lymphoma of the lung; may involve the upper respiratory tract and other parts of the body. SEE ALSO: polymorphic reticulosis. g. siderotica a form in which firm, brown foci that contain iron pigment (Gamna bodies) are present in an enlarged spleen. Wegener g. a disease, occurring mainly in the fourth and fifth decades, characterized by necrotizing granulomas and ulceration of the upper respiratory tract, with purulent rhinorrhea, nasal obstruction, and sometimes with otorrhea, hemoptysis, pulmonary infiltration and cavitation, and fever; exophthalmos, involvement of the larynx and pharynx, and glomerulonephritis may occur; the underlying condition is a vasculitis affecting small vessels, and is possibly due to an immune disorder. SEE ALSO: lymphomatoid g..

granulomatous (gran-u-lom′a-tus)
Having the characteristics of a granuloma.

granulomere (gran′u-lo-mer)
The central part of a blood platelet. SYN: chromomere (2) . [granulo- + G. meros, a part]

granulopenia (gran′u-lo-pe′ne-a)
SYN: granulocytopenia.

granuloplasm (gran′u-lo-plazm)
The inner substance of an ameba, or other unicellular organism, within the ectoplasm and surrounding the nucleus.

granuloplastic (gran′u-lo-plas′tik)
Forming granules.

granulopoiesis (gran′u-lo-poy-e′sis)
Production of granulocytes. In adults, granulocytes are produced chiefly in the red bone marrow of flat bones. SYN: granulocytopoiesis. [granulo(cyte) + G. poiesis, a making]

granulopoietic (gran′u-lo-poy-et′ik)
Pertaining to granulopoiesis. SYN: granulocytopoietic.

granulosa (gran-u-lo′sa)
SYN: stratum granulosum folliculi ovarici vesiculosi.

granulosis (gran-u-lo′sis)
A mass of minute granules of any character. g. rubra nasi erythema, papules, and occasional vesicles of the tip of the nose and extending upward and laterally to the cheeks, resulting from occlusion and chronic inflammation of sweat ducts.

granum (gra′num)
Singular of grana.

granzymes (gran′zimz)
Proteases with serine esterase activities that represent most of the granule content of T cytotoxic cells. It is not known if these enzymes are required for killing by the T cytotoxic cell. [granule + -zyme]

graph (graf)
1. A line or tracing denoting varying values of commodities, temperatures, urinary output, etc.; more generally, any geometric or pictorial representation of measurements that might otherwise be expressed in tabular form. 2. Visual display of the relationship between two variables, in which the values of one are plotted on the horizontal axis, the values of the other on the vertical axis; three-dimensional graphs that show relationships between three variables can be depicted and comprehended visually in two dimensions. [G. grapho, to write]

-graph
1. Something written, as in monograph, radiograph. 2. The instrument for making a recording, as in kymograph. Cf.:-gram. [G. grapho, to write]

graphanesthesia (graf′an-es-the′ze-a)
Tactual inability to recognize figures or letters written on the skin; may be due to spinal cord or brain disease. [G. graphe, writing + anaisthesia, fr. an- priv. + aisthesis, perception]

graphesthesia (graf-es-the′ze-a)
Tactual ability to recognize writing on the skin. [G. graphe, writing, + aisthesis, perception]

graphite (graf′it)
A crystallizable soft black form of carbon. SYN: black lead, plumbago.

grapho-
A writing, description. [G. grapho, to write]

graphology (gra-fol′o-je)
The study of handwriting as an indication of temperament, character, or personality. [grapho- + G. logos, study]

graphomania (graf-o-ma′ne-a)
Morbid and excessive impulse to write. [grapho- + G. mania, insanity]

graphomotor (graf-o-mo′ter)
Relating to the movements used in writing. [grapho- + L. motus, fr. movere, to move]

graphopathology (graf′o-path-ol′o-je)
Interpretation of personality disorders from a study of handwriting. See graphology. [grapho- + pathology]

graphophobia (graf-o-fo′be-a)
Morbid fear of writing. [grapho- + G. phobos, fear]

graphospasm (graf′o-spazm)
SYN: writer's cramp.

-graphy
A writing, a description. [G. grapho, to write]

grasp
The act of taking securely and holding firmly. palm g. holding an object by wrapping the palm and the fingers around it. pen g. a method, similar to that of holding a pen in writing, of grasping an instrument.

GRASS
Abbreviation for gradient-recalled acquisition in the steady state.

Grasset
Joseph, French physician, 1849–1918. See G. law, G. phenomenon, G. sign, G.-Gaussel phenomenon, Landouzy-G. law.

Gratiolet
Louis P., French anatomist, physiologist, and physician, 1815–1865. See G. fibers, under fiber, G. radiation.

grattage (gra-tazh′)
Scraping or brushing an ulcer or surface with sluggish granulations to stimulate the healing process. [Fr. scraping]

grave (grav)
Denoting symptoms of a serious or dangerous character. [L. gravis, heavy, g.]

gravel (grav′l)
Small concretions, usually of uric acid, calcium oxalate, or phosphates, formed in the kidney and passed through the ureter, bladder, and urethra. SYN: urocheras (1) , uropsammus (1) . [M.E., fr. O.Fr.]

Graves
Robert James, Irish physician remembered for his description of exophthalmic goiter in 1835, 1796–1853. See G. disease, G. ophthalmopathy, G. orbitopathy.

gravid
SYN: pregnant.

gravida (grav′i-da)
A pregnant woman. G. followed by a roman numeral or preceded by a Latin prefix (primi-, secundi-, etc.) designates the pregnant woman by number of pregnancies; e.g., g. I, primigravida; a woman in her first pregnancy; g. II, secundigravida; a woman in her second pregnancy. Cf.:para. [L. gravidus (adj.), fem. g., fr. gravis, heavy]

gravidic (grav-id′ik)
Relating to pregnancy or a pregnant woman.

gravidism (grav′id-izm)
SYN: pregnancy.

graviditas (grav-vid′i-tas)
SYN: pregnancy. [L.] g. examnialis SYN: extraamniotic pregnancy. g. exochorialis SYN: extrachorial pregnancy.

gravidity (gra-vid′i-te)
The number of pregnancies (complete or incomplete) experienced by a woman. [L. graviditas, pregnancy]

gravimeter (gra-vim′e-ter)
SYN: hydrometer. [L. gravis, heavy, + G. metron, measure]

gravimetric (grav-i-met′rik)
Relating to or determined by weight.

gravireceptors (grav′i-re-sep′terz)
Highly specialized receptor organs and nerve endings in the inner ear, joints, tendons, and muscles that give the brain information about body position, equilibrium, direction of gravitational forces, and the sensation of “down” or “up.” [L. gravis, heavy, + receptor]

gravitation (grav-i-ta′shun)
The force of attraction between any two bodies in the universe, varying directly as the product of their masses and inversely as the square of the distance between their centers; expressed as F = Gm1m2l−2, where G (Newtonian constant of g.) = 6.67259 × 10−11 m3 kg−1 s−2, m1 and m2 are the masses (in kg) of the two bodies, and l is the distance separating them in meters. [L. gravitas, weight]

gravity (grav′i-te)
The attraction toward the earth that makes any mass exert downward force or have weight. Strictly speaking, g. is the algebraic sum of the gravitational attraction of the earth and the opposing centrifugal effect of the mass's rotation around the earth. Thus, gravitational attraction at the north and south poles is larger than at the equator. A satellite in a stable orbit has zero g. because the centrifugal effect of orbital motion exactly balances the gravitational attraction of the earth. [L. gravitas] specific g. (sp. gr.) the weight of any body compared with that of another body of equal volume regarded as the unit; usually the weight of a liquid compared with that of distilled water. zero g. zero g..

Grawitz
Paul, German pathologist, 1850–1932. See G. basophilia, G. tumor.

gray (Gy) (gra)
The SI unit of absorbed dose of ionizing radiation, equivalent to 1 J/kg of tissue; 1 Gy = 100 rad. SYN: griseus. [Louis H. G., British radiologist, 1905–1965]

Greeff
Richard, German ophthalmologist, 1862–1938. See Prowazek-G. bodies, under body.

green (gren)
A color between blue and yellow in the spectrum. For individual g. dyes, see specific names. Scheele g. SYN: cupric arsenite.

Greenfield
L., American surgeon who designed the G. filter. See G. filter.

gregaloid (greg′a-loyd)
Denoting a loose colony of protozoa formed by the chance union of independent cells, especially among sarcodines with pseudopodial adherence. [L. grex (greg-), a flock]

Gregarina (greg-a-ri′na)
A genus of sporozoan protozoa (phylum Apicomplexa, subclass Gregarinia), parasitic in annelids and arthropods, and lacking schizogony and endodyogeny in the life cycle. [L. gregarius, gregarious, fr. grex (greg-), a flock]

gregarine (greg′a-ren)
A member of the subclass Gregarinia.

Gregarinia (greg′a-rin′i-a)
A sporozoan subclass consisting of a number of parasites of the body cavity and intestinal tract of invertebrates, especially annelids and arthropods; typical genera include Gregarina in insects and Monocystis in earthworms.

gregarinosis (greg′a-ri-no′sis)
A disease due to the presence of gregarines.

Greig
David M., Scottish physician, 1864–1936. See G. syndrome.

gression (gres′shun)
Displacement of a tooth backward. [L. grador, pp. gressus, to walk, fr. gradus, a step]

grey matter
See gray matter.

Grey Turner
See Turner.

GRH
Abbreviation for gonadotropin-releasing hormone.

grid (grid)
1. A chart with horizontal and perpendicular lines for plotting curves. 2. In x-ray imaging, a device formed of lead or aluminum strips for preventing scattered radiation from reaching the x-ray film. [M.E. gridel, fr. L. craticula, lattice] Amsler g. SYN: Amsler chart. focused g. a g. (2) in which the divergent beam of x-rays from a particular distance range will be parallel to the lead strips. Wetzel g. chart of growth, plotting height, weight, physical fitness and related aspects of young and adolescent children during growth.

Gridley
Mary F., U.S. medical technologist, 1908–1954. See G. stain, G. stain for fungi.

grief (gref)
A normal emotional response to an external loss; distinguished from a depressive disorder since it usually subsides after a reasonable time.

Griesinger
Wilhelm, German neurologist, 1817–1868. See G. disease, bilious typhoid of G., G. sign.

grindelia (grin-de′le-a)
The dried leaves and flowering tops of G. camporum, g. humilius, and G. squarrosa (family Compositae); used as an expectorant; a fluid extract has been used externally in the treatment of rhus poisoning. [David H. Grindel, German botanist, 1776–1836]

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