| giant cell tumour of tendon sheath | A nodule, possibly inflammatory in nature, arising commonly from the flexor sheath of the fingers and thumb; composed of fibrous tissue, lipid-and haemosiderin-containing macrophages, and multinucleated giant cells. Synonym: localised nodular tenosynovitis. (05 Mar 2000) |
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| villous tumour | <tumour> A papilloma composed of slender, finger-like excrescences occurring in the bladder or large intestine, or from the choroid plexus of the cerebral ventricles; villous papilloma's of the colon are usually sessile and frequently become malignant. Synonym: villous tumour. (05 Mar 2000) |
| Gleason's tumour grade | A classification of adenocarcinoma of the prostate by evaluation of the pattern of glandular differentiation; the tumour grade, know as Gleason's score, is the sum of the dominant and secondary patterns, each numbered on a scale of 1 to 5. (05 Mar 2000) |
| glomus jugulare tumour | A paraganglioma involving the glomus jugulare, a microscopic collection of chemoreceptor tissue in the adventitia of the bulb of the jugular vein. It may cause paralysis of the vocal cords, attacks of dizziness, blackouts, and nystagmus. It is not resectable but radiation therapy is effective. It regresses slowly, but permanent control is regularly achieved. (12 Dec 1998) |
| glomus tumour | A blue-red, extremely painful paraganglioma involving a glomeriform arteriovenous anastomosis (glomus body), which may be found anywhere in the skin, most often in the distal portion of the fingers and toes, especially beneath the nail. They may also occur in the stomach and nasal cavity. It is composed of specialised pericytes (sometimes termed glomus cells), usually in single encapsulated nodular masses which may be several millimeters in diameter. When located in the usual subungual site, the abundant innervation makes the tumour exquisitely painful; when located elsewhere, the glomus tumour is painless. (12 Dec 1998) |
| pearl tumour | An obsolete term for cholesteatoma. (05 Mar 2000) |
| cellular tumour | A tumour composed mainly of closely packed cells. (05 Mar 2000) |
| cerebellopontine angle tumour | This is a benign tumour of the 8th cranial nerve that affects approximately 1 out of 100,000 people. This tumour arises from the myelin forming Schwann cells that coat the 8th cranial nerve (acoustic nerve). Clinical presentation usually includes hearing deficit. Diagnosis can be made with auditory evoked potentials and/or MRI scanning of the brain. Vertigo and tinnitus may be associated symptoms. Surgical removal of this tumour involves dissection, cautery and obliteration with laser. Causes: acoustic neuroma (90%), meningioma (7%), epidermoid (3%), uncommon: metastasis, trigeminal neuroma, arachnoid cyst, aneurysm, vertebro-basilar dolichoectasia (12 Dec 1998) |
| melanotic neuroectodermal tumour of infancy | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |
| Godwin tumour | Benign tumour-like masses of lymphoid tissue in the parotid gland, containing scattered small, mainly solid islands of epithelial cells. Synonym: Godwin tumour. (05 Mar 2000) |
| retinal anlage tumour | A benign neoplasm of neuroectodermal origin that most often involves the anterior maxilla of infants in the first year of life. It presents clinically as a rapidly growing blue-black lesion producing a destructive radiolucency; histologically, it is characterised by small round undifferentiated tumour cells interspersed with larger polyhedral melanin-producing cells arranged in an alveolar configuration. Synonym: melanoameloblastoma, pigmented ameloblastoma, pigmented epulis, progonoma of jaw, retinal anlage tumour. (05 Mar 2000) |
| rhabdoid tumour | A rare but highly lethal childhood tumour found almost exclusively in infants. Histopathologically, it resembles rhabdomyosarcoma but the tumour cells are not of myogenic origin. Although it arises primarily in the kidney, it may be found in other parts of the body. The rhabdoid cytomorphology is believed to be the expression of a very primitive malignant cell. (12 Dec 1998) |
| Merkel cell tumour | A rare malignant cutaneous tumour seen in sun-exposed skin of elderly patients composed of dermal nodules of small round cells with scanty cytoplasm in a trabecular pattern; the tumour cells contain cytoplasmic dense core granules resembling neurosecretory granules seen in Merkel cells. Synonym: primary neuroendocrine carcinoma of the skin, trabecular carcinoma. (05 Mar 2000) |
| chemoreceptor tumour | Aortic body, carotid body, chemoreceptor, or glomus jugulare tumour; nonchromaffin paraganglioma; receptoma; a relatively rare, usually benign neoplasm originating in the chemoreceptor tissue of the carotid body, glomus jugulare, and aortic bodies; consisting histologically of rounded or ovoid hyperchromatic cells that tend to be grouped in an alveolus-like pattern within a scant to moderate amount of fibrous stroma and a few large thin-walled vascular channels. Compare: paraganglioma. Synonym: aortic body tumour, carotid body tumour, chemoreceptor tumour, glomus jugulare tumour, nonchromaffin paraganglioma. Origin: chemo-+ G. Dektes, receiver, fr. Dechomai, to receive, + -oma, tumour (05 Mar 2000) |
| granular cell tumour | Unusual tumour affecting any site of the body, but most often encountered in the head and neck. Considerable debate has surrounded the histogenesis of this neoplasm; however, it is considered to be a myoblastoma of, usually, a benign nature. It affects women more often than men. When it develops beneath the epidermis or mucous membrane, it can lead to proliferation of the squamous cells and mimic squamous cell carcinoma. (12 Dec 1998) |