Chemodectoma (non-chromaffin paraganglioma) of the ninth intercostal space

Aortico-pulmonary paraganglioma: report of a case with ultrastructural study and review of the literature

The light microscopic and ultrastructural features of an aortico-pulmonary paraganglioma (A-PP) are presented. The tumor was characterized by organoid clustering of neoplastic chief cells to form Zellballen. Argyrophilic granules were demonstrated within chief cell cytoplasm using a modified Grimelus technique. Ultrastructurally, three distinct cell types were present within the tumor: endothelial cells, pericytes and neoplastic chief cells. Membrane-bound neurosecretory granules were present and measured 100 to 2000 nm in diameter. "Light" and "dark" chief cells were less distinct than previously reported in other head and neck paragangliomas. Analysis of the 36 documented A-PP reported in the English literature reveals that the tumor has been either incompletely excised or has been considered unresectable in one-third of the cases. The reported surgical mortality is 9%, or approximately equal to the incidence of malignant behavior. The treatment of choice is surgical resection but when this is not possible, radiation may be a useful adjunct in therapy.

Mediastinal paragangliomas (aortic body tumor): a report of four cases and a review of the literature

Four cases of paraganglioma originating in the supra-aortic or aortico-pulmonary bodies are described. A review of the reported examples of aortic body tumors and a study of these four cases indicate that there is a high incidence of aggressive tumor growth in the mediastinum, with resultant important morbidity or death in 16 of 35 cases. The morphologic features of aortic body tumors are identical to those of paragangliomas of other locations, and the occurrence of invasive growth and/or metastasis cannot be predicted on histologic grounds.

Intrathoracic chemodectoma with multiple localisations

In 1958 a mediastinal tumour was discovered in an asymptomatic woman with a history of vomiting and an oesophageal anomaly which had not been treated. A tumour of the anterosuperior mediastinum in relation to the aortic arch was extirpated and proved to be a chemodectoma or non-chromaffin paraganglioma. At subsequent follow-ups the mediastinum was never normal and the heart size progressively increased, the oesophageal anomaly remaining unchanged. A small opacity appeared in the left lung in 1974. An operation performed in 1975 revealed an osteochondroma in the lung, pericarditis, and an intrapericardial chemodectoma. The oesophagus was not explored. An intrathoracic chemodectoma is rare. The importance of angiography in its diagnosis is emphasised. Malignant degeneration is seldom observed. Therapy is surgical, the tumour being radioresistant. The possibility to be considered in our patient was either relapse of the tumour with degeneration or multiple localisations of the tumour.

Intrathoracic carotid-body tumour (chemodectoma)

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THE CAROTID BODY: A PATHOLOGIST'S VIEW

A review of the literature on the histogenesis and function of the carotid body suggests that the results and the original interpretations of embryological, histological and histochemical investigations have not provided a convincing explanation of the origin of this structure. That the carotid body is developed from mesoderm and is a sensory organ (chemoreceptor) seems unlikely because of: morphological similarities between some of the carotid body tumours and certain tumours of peripheral nerves; certain electron microscopic similarities between the cells of carotid body and adrenal medulla; chromatographic demonstration of catecholamines in the human carotid bodies; and contradictory results of both animal experiments and clinical observations concerning function of this structure.It is concluded that the carotid body arises from ectoderm and should probably be classified as a gland of internal secretion, related to the adrenal medulla and other paraganglia.

MALIGNANT CAROTID BODY TUMOUR IN THE NECK OF A NEWBORN INFANT

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