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Biomedical subjects

J G Azzopardi

Publications and source records attributed to J G Azzopardi.

At least 55 records · Page 3Linked to original sources
PubMed1978

The hyaline cell: a distinctive feature of "mixed" salivary tumours.

We have identified and described a distinctive type of cell which is characteristic of the "mixed" salivary tumour. This "hyaline cell" or plasmacytoid cell is particularly common and conspicuous in "mixed" tumours of the palate and other sites in the mouth. It occurs also in tumours of the major glands, but with much lesser frequency. The hyaline cell is found in "mixed" salivary-type tumours in other sites, e.g. the skin. It is not present in the other types of salivary tumour, notably adenoid cystic carcinoma, adenolymphoma, mucoepidermoid and acinic tumour. Ultrastructural study suggests that the hyaline cell is an indicator of myoepithelial differentiation. Current concepts of the acceptable pathways of myoepithelial differentiation in "mixed" tumours are discussed briefly. The specificity of the hyaline cell will probably prove valuable in separating "mixed" tumours from monomorphic adenomas, thus retaining the identity of the latter. The hyaline cell is almost as distinctive a feature of "mixed" tumours as is myxochondroid tissue and its specificity is of practical value in the diagnosis and classification of salivary tumours.

Adenoma, Pleomorphic↗
PubMed1977

Melanocyte colonization and pigmentation of breast carcinoma.

Colonization of mammary cancers by melanocytes with attendant pigmentation of cancer cells by melanin occurs in most cases of breast cancer in which the dermal--epidermal interface is reached by the tumour cells. There is evidence to suggest that the mammary cancer may become colonized at the expense of the epidermis, which is focally depleted of melanocytes. Melanocytes can even be found in groups of tumour cells within lymphatics. Colonization and pigmentation of breast cancer is usually only easily detected by selective staining methods. In very rare cases it can be gross and easily detectable in routine stains. The implications of this migratory phenomenon are discussed in terms of the biology of the melanocyte.

Breast Neoplasms↗
PubMed1977

Blue naevi of lymph node capsule.

Blue naevi are reported for what is believed to be the first time in the capsule and fibrous trabeculae of lymph nodes. In one of the two cases that nodal blue naevus was accompanied by an ordinary blue naevus in the regional skin. These blue naevi are compared with the 'naevus-cell aggregates' in nodal capsule, the histogenesis of which is currently disputed. A developmental migratory arrest of melanocytes is thought to be the histogenetic mechanism involved in the production of these blue naevi in lymph nodes.

Adult↗
PubMed1976

Vascular infiltration in benign breast disease.

Infiltration of the walls of blood vessels by mammary epithelium was found in two cases of sclerosing adenosis. Survey of a series of cases of sclerosing adenosis and severe epitheliosis revealed a 10 per cent incidence of vascular infiltration. Usually only a single vein was involved but in the propositus an artery and two veins were infiltrated. The findings highlight the infiltrative propensities of sclerosing adenosis, already recognised as infiltrating nerve sheaths. The vascular lesions appear to be benign structurally and this is borne out by the clinical behaviour.

Adult↗
PubMed1975

Inverted follicular keratosis.

Attention is drawn to a benign skin tumour which has escaped recognition in the British lieterautre. Inverted folliculr keratosis can be mistaken clinically for basal cell carcinoma and a variety of benign skin lesions. Pathologically it is easliy confused with squamous carcinoma, a serious error because this lesion occurs dominantly on the face. The lesion is thought to arise from the infundibulum of hair follicte.

Adult↗
PubMed1975

Lobular carcinoma of the breast: a special variant of mucin-secreting carcinoma.

There is currently much speculation over the precise nature of lobular carcinoma in-situ of the breast and its significance. Histochemical study shows that it is rich in sialomucin. This has a characteristic intracellular distribution which distinghishes lobular carcinoma in-situ from cancerization of lobules. The same histochemical features are seen in the infiltrative phase of the tumour. These findings invalidate the concept that it is a myoepithelial-cell tumour. Practical applications of the distinctive pattern of mucin secretion are discussed.

Adenocarcinoma, Mucinous↗
PubMed1971

Malignant lymphoma of parotid associated with Mikulicz disease (benign lymphoepithelial lesion).

Benign lymphoepithelial lesion (Mikulicz disease) is generally regarded as an inflammatory disorder of unknown aetiology, characterized by epimyoepithelial islands, and unrelated to malignant lymphoma. Five cases have been collected which show evidence at the same site of both Mikulicz disease and a malignant lymphoma. The latter took the form of reticulum-cell sarcoma or Hodgkin's disease. The two diseases were discovered simultaneously or the malignant lymphoma was detected at a subsequent date. The probable sequence of events is discussed. These cases are regarded as one of the best illustrations in man of an autoimmune disorder being followed by the development of malignant lymphoma. It is concluded that so-called benign lymphoepithelial lesion is not always innocuous and an attempt is made to establish histological criteria which might be regarded with suspicion in a particular case.

Adult↗
PubMed1970

Endocrine and metabolic disordes in bronchial carcinoma.

In an unselected series of 185 patients with histologically confirmed bronchial carcinoma 16 had endocrine disturbances attributable to the tumour (excluding pulmonary osteoarthropathy). Of these, 11 patients had hypercalcaemia; three inappropriate secretion of antidiuretic hormone; one Cushing's disease; three hypertrophic osteoarthropathy; and one gynaecomastia. Cushing's disease and inappropriate antidiuresis are specifically associated with oat-cell tumours, and hypercalcaemia occurs most frequently with squamous carcinoma. A negative correlation exists between gynaecomastia and osteoarthropathy on the one hand and oat-cell carcinoma on the other.

Adenocarcinoma↗
PubMed1969

Bronchial carcinoma and hypercalcaemia.

Hypercalcaemia due to malignant disease, in the absence of bone metastases, is generally regarded as a rare event. It occurred in 16% of a series of cases of bronchial carcinoma coming to necropsy. Hypercalcaemia is a relatively common complication of bronchial carcinoma. The hypercalcaemia is usually accompanied by hypophosphataemia and, in this respect, must be distinguished from the hypercalcaemia that may be found with breast carcinoma. It is frequently accompanied by hypokalaemic alkalosis; this must not be confused with the metabolic disorder that results from the production of ectopic ;ACTH'. The bones sometimes show changes of osteitis fibrosa akin to those seen in hyperparathyroidism. Cystic disease of bone recognizable radiologically is rare, probably because of the relatively short duration of the metabolic disturbance. The parathyroids are usually mildly atrophic. There is no evidence that the main pathogenetic mechanism is stimulation of the parathyroids by the tumour. Acceptable instances of parathyroid hyperplasia are very rare: the significance of these exceptional cases awaits further study.Squamous carcinoma of the bronchus is the type mainly incriminated. Oat-cell carcinoma and bronchial adenocarcinoma are involved less frequently than expected by chance. The significance of the tumour types implicated is discussed in relation to the possible pathogenesis.

Adenocarcinoma↗