Classification of paragangliomas based on site of origin groups cervical paragangliomas arising from the carotid body in one group and those arising from the ganglion nodosum, known as glomus vagale or vagal paragangliomas, in another.
Paragangliomas of the head and neck originate most commonly from the paraganglia within the carotid body, vagal nerve, middle ear, and jugular foramen. Also called glomus tumors, they arise from paraganglion cells of neuroectodermal origin frequently located near nerves and vessels.
CLINICAL CLASSIFICATION OF TEMPORAL PARAGANGLIOMAS CT is almost crucial to evaluate temporal paragangliomas. The extent of temporal bone destruction is used to classify these tumors according to the Fisch classification (Table 1) (27). Table 1.Paraganglioma. Paraganglioma is a neuroendocrine neoplasm arising from paraganglia (chemoreceptors derived from neural crest responding to changes in blood oxygen and carbon dioxide levels) situated in the vicinity of the jugular bulb (glomus jugulare) or the medial cochlea promontory of the middle ear (glomus tympanicum), together representing nearly 80% of all head and neck paragangliomas.Terminology Paraganglia are clusters of neuroendocrine cells dispersed throughout the body and closely related to the autonomic nervous system, with either parasympathetic or sympathetic function. The largest cluster of cells is found within the adrenal medulla, with smaller collections in the paravertebral space, and head and neck region.
According to the World Health Organization classification of neuroendocrine tumors, paragangliomas are classified as having a neural cell line of origin. In the categorization proposed by Wick, the paragangliomas belong to Group II.Read More
The paraganglionic system comprises the adrenal medulla and the extra-adrenal paraganglia. The former gives rise to pheochromocytomaswhereas the latter give rise to (extra-adrenal) paragangliomas. The adrenal medulla is the largest collection of paraganglia, and the most common site of paragangliomas (called pheochromocytomas in this location).Read More
Pheochromocytoma is a rare tumor that forms in the adrenal medulla (the center of the adrenal gland). Paragangliomas form outside the adrenal gland. Certain inherited disorders and changes in certain genes increase the risk of pheochromocytoma or paraganglioma.Read More
Phaeochromocytomas are rare neuroendocrine tumours of neural crest origin, which often produce excess catecholamines (1). Although usually arising from the chromaffin cells of the adrenal medulla, phaeochromocytomas may also arise at other sites of sympathetic or parasympathetic chromaffin tissue anywhere from the base of the skull to the pelvis.Read More
Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors that arise in the adrenal medulla and in extra-adrenal locations, such as the head, neck, thorax, abdomen, and pelvis. Classification of these tumors into those with or without metastatic potential on the basis of gross or microscopic features is challenging.Read More
The term “paraganglioma” is a generic one applied to tumors arising from paraganglia regardless of location ( 1, 2 ). The only exception is the paraganglioma of the adrenal medulla, which is universally known as pheochromocytoma. By extension, paragangliomas located outside the adrenal gland have been designated as extraadrenal paragangliomas.Read More
This pictorial essay provides a classification system for the most common intramedullary spinal masses and describes distinguishing imaging features that will aid the radiologist in providing a relevant differential diagnosis to guide further management.Read More
Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors that arise in the adrenal medulla and in extra-adrenal locations, such as the head, neck, thorax, abdomen, and pelvis. Classification of these tumors into those with or without metastatic potential on the basis of gross or microscopic features is challenging. Recent insights and scoring systems have attempted to.Read More
Paragangliomas (also known as glomus tumors) are benign neuroendocrine tumors. Glomus tympanicum and glomus jugulare are tumors that present in the temporal bone with pulsatile tinnitus, conductive hearing loss, and cranial nerve neuropathy. The classification system of these tumors and the pathophysiology are described. Temporal bone imaging with CT and MRI is frequently required.Read More
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