| carcinoma, basal cell | A malignant skin neoplasm that seldom metastasizes but has potentialities for local invasion and destruction. Clinically it is divided into types: nodular, cicatricial, morphaic, and erythematoid (pagetoid). More than 95% of these carcinomas occur in patients over 40. They develop on hair-bearing skin, most commonly on sun-exposed areas. Approximately 85% are found on the head and neck area and the remaining 15% on the trunk and limbs. (12 Dec 1998) |
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| carcinoma, giant cell | An epithelial neoplasm characterised by unusually large anaplastic cells. It is highly malignant with fulminant clinical course, bizarre histologic appearance and poor prognosis. It is most common in the lung and thyroid. (12 Dec 1998) |
| carcinoma, islet cell | A carcinoma of the islets of langerhans. (12 Dec 1998) |
| carcinoma, large cell | A tumour of undifferentiated (anaplastic) cells of large size. It is usually bronchogenic. (12 Dec 1998) |
| carcinoma, merkel cell | A carcinoma arising from merkel cells located in the basal layer of the epidermis and occurring most commonly as a primary neuroendocrine carcinoma of the skin. Merkel cells are tactile cells of neuroectodermal origin and histologically show neurosecretory granules. The skin of the head and neck are a common site of merkel cell carcinoma, occurring generally in elderly patients. (12 Dec 1998) |
| carcinoma, non-small-cell lung | A heterogeneous aggregate of at least three distinct histological types of lung cancer, including squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. They are dealt with collectively because of the shared properties of poor response to conventional chemotherapy and the potential for cure with surgical resection in a fraction of patients. (12 Dec 1998) |
| carcinoma, renal cell | Carcinoma of the renal parenchyma usually occurring in middle age or later and composed of tubular cells in varying arrangements. It was first described in 1826. Possible causal factors are environmental, hormonal, cellular, and genetic. Smoking is a definite risk factor and obesity is associated with increased risk. Renal cell carcinoma accounts for approximately 3% of adult cancer; the male-female ratio is 2:1. It is more common among urban residents than rural. (12 Dec 1998) |
| carcinoma, signet ring cell | A highly malignant, mucus-secreting tumour in which the mucus-secreting cells are anaplastic and appear rounded, with the nucleus displaced to one side by a globule of mucus in the cytoplasm. (12 Dec 1998) |
| carcinoma, small cell | An anaplastic, highly malignant, and usually bronchogenic carcinoma composed of small ovoid cells with scanty neoplasm. It is characterised by a dominant, deeply basophilic nucleus, and absent or indistinct nucleoli. There are admixtures of small cell lung carcinoma with other types of lung cancer. Small cell carcinomas are distinguished by their distinctive biological features, response to chemotherapy and radiotherapy, and by their nearly universal tendency to develop overt or subclinical metastases, which frequently eliminates surgery in most patients. (12 Dec 1998) |
| carcinoma, squamous cell | A carcinoma derived from stratified squamous epithelium. It may also occur in sites where glandular or columnar epithelium is normally present. (12 Dec 1998) |
| carcinoma, transitional cell | A malignant neoplasm derived from transitional epithelium, occurring chiefly in the urinary bladder, ureters or renal pelves (especially if well differentiated), frequently papillary. Transitional cell carcinomas are graded 1 to 3 or 4 according to the degree of anaplasia, grade 1 appearing histologically benign but being liable to recurrence. (12 Dec 1998) |
| cardiac cell | Strictly speaking any cell of or derived form the cardium of the heart, but often used loosely of heart cells. (18 Nov 1997) |
| packed cell volume | <haematology> Measurement of the proportion of the blood occupied by the red blood cells. Normal values are 40-54% in males, 35-47% in females. (13 Nov 1997) |
| packed red blood cell | <haematology> Red blood cells collected from one individual that are packed into a small volume for transfusion into a patient. (16 Dec 1997) |
| macroglia cell | <pathology> A glial cell found in vertebrate brain, named for its characteristic star like shape. Astrocytes lend both mechanical and metabolic support for neurons, regulating the environment in which they function. See: oligodendrocytes. (18 Nov 1997) |