Chemodectoma

A paraganglioma is a rare neuroendocrine neoplasm that may develop at various body sites (including the head, neck, thorax and abdomen). Unlike other types of cancer, there is no test that determines benign from malignant tumors; long-term followup is therefore recommended for all individuals with paraganglioma. Approximately 50% of patients with recurrent disease experience distant metastasis. The five-year survival in the setting of metastatic disease is 40% to 45%.Micrograph of a carotid body tumorGlomus jugulare tumorEctopic functional paraganglioma (glomus jugulare) in a patient with VHL. T2 weighted MRI at the same location demonstrates a high signal mass consistent with a paraganglioma. Extra adrenal paragangliomas can be found in VHL (arrow).S100 immunostain highlighting the sustentacular cells in a paraganglioma A paraganglioma is a rare neuroendocrine neoplasm that may develop at various body sites (including the head, neck, thorax and abdomen). Unlike other types of cancer, there is no test that determines benign from malignant tumors; long-term followup is therefore recommended for all individuals with paraganglioma. Approximately 50% of patients with recurrent disease experience distant metastasis. The five-year survival in the setting of metastatic disease is 40% to 45%. Most paragangliomas are either asymptomatic or present as a painless mass. While all contain neurosecretory granules, only in 1–3% of cases is secretion of hormones such as catecholamines abundant enough to be clinically significant; in that case manifestations often resemble those of pheochromocytomas (intra-medullary paraganglioma). Anterior triangle of the neck. About 75% of paragangliomas are sporadic; the remaining 25% are hereditary (and have an increased likelihood of being multiple and of developing at an earlier age). Mutations of the genes for the succinate dehydrogenase, SDHD (previously known as PGL1), SDHA, SDHC (previously PGL3) and SDHB have been identified as causing familial head and neck paragangliomas. Mutations of SDHB play an important role in familial adrenal pheochromocytoma and extra-adrenal paraganglioma (of abdomen and thorax), although there is considerable overlap in the types of tumors associated with SDHB and SDHD gene mutations. Paragangliomas may also occur in MEN type 2A and 2B. Other genes related to familial paraganglioma are SDHAF2, VHL, NF1, TMEM127, MAX and SLC25A11.