| 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) |
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| 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) |
| granulosa cell tumour | An ovarian tumour originating in the cells of the primordial membrana granulosa of the graafian follicle. It may be associated with excessive production of estrin, inducing endometrial hyperplasia with menorrhagia. It can be benign or malignant. It is soft, solid, white or yellow, and consists of small round cells sometimes enclosing call-exner bodies. Larger lipid-containing cells may be present. Granulosa cell tumours are seen in women of all ages. Treatment depends on the age of the patient and the extent of the disease. (12 Dec 1998) |
| Grawitz' tumour | Old eponym for renal adenocarcinoma. (05 Mar 2000) |
| mesonephroid tumour | A rare tumour of the female genital tract, most often the ovary, formerly considered to be derived from mesonephric rests. Two varieties are recognised: (1) clear cell carcinoma, so called because of its histologic resemblance to renal cell carcinoma, and now considered to be of muellerian duct derivation and (2) an embryonal tumour (called also endodermal sinus tumour and yolk sac tumour), occurring chiefly in children. The latter variety may also arise in the testis. (12 Dec 1998) |
| metastatic brain tumour | A malignant growth in brain tissue that has spread from another primary cancer site (for example breast cancer, malignant melanoma, lung cancer) in the body. (27 Sep 1997) |
| Gubler's tumour | A fusiform swelling on the wrist in lead palsy. (05 Mar 2000) |
| RNA tumour virus | The family of retroviruses (Retroviridae) that can cause tumours. They are enveloped by membrane derived from the plasma membrane of the host cell, from which they are released by budding without lysing the cell. Within each virion is a pair of single stranded RNA molecules. Replication involves a DNA intermediate made on an RNA template by the enzyme reverse transcriptase. (18 Nov 1997) |
| RNA tumour viruses | Virus's of the subfamily Oncovirinae. (05 Mar 2000) |
| phantom tumour | Accumulation of fluid in the interlobar spaces of the lung, secondary to congestive heart failure, radiologically simulating a neoplasm. (05 Mar 2000) |