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Biomedical subjects

J M MacKenzie

Publications and source records attributed to J M MacKenzie.

21 records · Page 2Linked to original sources

Pleomorphic xanthoastrocytoma in a 62-year-old male.

Pleomorphic xanthoastrocytoma has been described as a distinct clinicopathological entity with a relatively favourable prognosis. However, tumours closely resembling this entity have been shown to have the potential for aggressive behaviour, and to represent, on closer scrutiny, a number of disparate neoplasms. A case is described which, although otherwise typical of pleomorphic xanthoastrocytoma, occurred in a man of 62 years, and it is suggested that it should be considered a specific histological, rather than a clinicopathological entity.

Astrocytoma↗

The evolution of an oligodendroglioma into a primitive neuroectodermal tumour.

Oligodendrogliomas may comprise a biologically heterogenous group of tumours. There is disagreement about the relationship between their histological features and subsequent behaviour, and evolution of histologically typical oligodendrogliomas into more malignant neoplasms has been described. We describe a supratentorial oligodendroglioma in a 4-year-old boy which recurred 9 months after initial resection when it showed foci of histologically primitive cells, not present in the initial specimen. It recurred again at the same site 20 months later following a course of radiotherapy, but showed on this occasion the appearances of a primitive neuroectodermal tumour (PNET) with astrocytic and ependymal, but not oligodendroglial, differentiation. The evidence suggests evolution of an oligodendroglioma into a PNET, and raises the possibility that some oligodendrogliomas may arise by differentiation from a pool of proliferating primitive cells which may occasionally become the dominant population.

Brain Neoplasms↗

Are all cardio-embolic strokes embolic? An autopsy study of 100 consecutive acute ischaemic strokes.

Estimates of the frequency of different types of ischaemic stroke vary widely, particularly those said to be of embolic aetiology. This retrospective autopsy study of 100 acute ischaemic strokes was undertaken to clarify the incidence of cardio-embolic stroke. Criteria for separating cardio-embolic from other forms of stroke were defined. Using these criteria, 26% of acute ischaemic strokes were cardio-embolic, 28% thrombotic, 12% atheromatous and the remainder due to various other causes including hypoperfusion with 11% being of undetermined aetiology. A significantly higher incidence of non-hypertensive cardiac disease was found in the group in whom no thrombus or thrombo-embolus was found at autopsy, suggesting that some of these strokes may have been due to unrecognised cerebral hypoperfusion. Haemodynamic stroke is probably an important and underrecognised form of acute ischaemic stroke.

Acute Disease↗