| Duret's lesion | Small haemorrhage(s) in the floor of the fourth ventricle or beneath the aqueduct of Sylvius. (05 Mar 2000) |
|---|---|
| Janeway lesion | One of the stigmata of infectious endocarditis: irregular, erythematous, flat, painless macules on the palms, soles, thenar and hypothenar eminences of the hands, tips of the fingers, and plantar surfaces of the toes; rarely a diffuse rash. In acute endocarditis the lesions may be haemorrhagic or purple. (05 Mar 2000) |
| upper motor neuron lesion | Injury to cerebral descending (corticonuclear) fibres above the brainstem or spinal motor nerve nucleus. Synonym: upper motor neuron lesion. (05 Mar 2000) |
| Lennert's lesion | <tumour> Malignant lymphoma with a high proportion of diffusely scattered epithelioid cells, tonsillar involvement, and an unpredictable course. Synonym: Lennert's lesion. (05 Mar 2000) |
| lesion | <pathology> Any pathological or traumatic discontinuity of tissue or loss of function of a part. Origin: L. Laesio, laedere = to hurt (18 Nov 1997) |
| Lohlein-Baehr lesion | Focal embolic glomerulonephritis occurring in bacterial endocarditis. Synonym: Baehr-Lohlein lesion. (05 Mar 2000) |
| lower motor neuron lesion | Injury to motor cells in the brainstem or spinal cord, or of the axons derived from them. (05 Mar 2000) |
| adrenal mass | <radiology> Metastasis, most common (especially lung, melanoma), primary adenocarcinoma, large at diagnosis (greater than 5 cm), usually functional (increased corticosteroids most likely to be Cushing's), rapid growth, benign adrenal adenoma, with or without functional, nonfunctional occurs in 2-8% of population, diff from metastasis: MRI (metastasis bright on T2), biopsy, follow, pheochromocytoma, neuroblastoma, myelolipoma, cyst / pseudocyst see also: adrenal calcification, haemorrhage (12 Dec 1998) |
| apperceptive mass | The already existing knowledge base in a similar or related area with which the new perceptual material is articulated. (05 Mar 2000) |
| atomic mass | <chemistry, physics> The mass of an atom relative to other atoms. The present-day basis of the scale of atomic weights is carbon, the most common isotope of this element has arbitrarily been assigned an atomic weight of 12. The unit of the scale is 1/12 the weight of the carbon atom or roughly the mass of one proton or one neutron. The atomic weight of any element is approximately equal to the total number of protons and neutrons in is nucleus (16 Dec 1997) |
| atomic mass unit | <chemistry> One-twelfth the mass of a neutral atom of the most abundant isotope of carbon. (16 Dec 1997) |
| bilateral adrenal mass | <radiology> Acute granulomatous disease (e.g., TB), metastases (bilateral in 15%), pheochromocytoma (bilateral in 10%), adrenal hyperplasia (adenoma), spontaneous adrenal haemorrhage (12 Dec 1998) |
| body mass index | One of the anthropometric measures of body mass; it has the highest correlation with skinfold thickness or body density. (12 Dec 1998) |
| breast mass | <oncology, surgery> A breast lump may be benign or cancerous. Examples of breast lumps include: breast abscess, fat necrosis, fibroadenoma, fibrocystic breast disease and breast cancer. A breast biopsy is the best way to determine the aetiology of a breast lump. Remember, 80 to 85% of all biopsies are benign. (27 Sep 1997) |
| para-sellar mass | <radiology> Mnemonic: SATCHMO, S sphenoid sinus tumour, A aneurysm / adenoma of pituitary, T teratoid lesion, C craniopharyngioma, H hypothalamic glioma / histiocytoma, M meningioma / metastasis, O optic glioma less common lesions: germinoma, epidermoid, hamartoma, chordoma, arachnoid cyst (12 Dec 1998) |