[Head and neck paragangliomas. Embryological origin and anatomical characteristics: topographic distribution and vascularization pattern]. / Paragangliomas cervicocefálicos. Origen embriológico y características anatómicas: distribución topográfica y patrón de vascularización.

Paragangliomas are tumors that arise in the extraadrenal paraganglia and result from migration of neural crest cells during embryonic development. Based on their anatomical distribution, innervation and microscopic structure, these tumors can be classified into interrelated families: branchiomeric paraganglia (related to the branchial clefts and arches), intravagal, aortic-sympathetic and visceral-autonomic. Head and neck paragangliomas belong mainly to the first two of these families. The present article is divided into two parts. The first part reviews the embryological origin of these tumors. Special emphasis is placed on the process of neurulation or neural tube formation, neurosegmentation (with a summary of the mechanisms involved in the initial segmentation of the neural tube and of the hindbrain and spinal medulla), and the development of the sensory placodes and secondary inductions in the cranial region. Subsequently, the neural crest is analyzed, with special attention paid to the cranial neural crest. The embryonogenesis of paragangliomas is also described. The second part describes the topographical distribution of head and neck paragangliomas according to their localization: jugulotympanic, orbit, intercarotid, subclavian and laryngeal. The embryonogenesis and most important anatomical characteristics are described for each type.

Paragangliomas cervicocefálicos. Origen embriológico y características anatómicas: distribución topográfica y patrón de vascularización / Head and neck paragangliomas. Embryological origin and anatomical characteristics: topographic distribution and vascularization pattern

Los paragangliomas son neoplasmas procedentes de paraganglios extra adrenales que derivan de la migración de las células de la cresta neural durante el desarrollo embrionario. Según su distribución anatómica, su inervación y su estructura microscópica, pueden ser agrupados en familias interrelacionadas, diferenciándose paraganglios branquioméricos (relacionados con los arcos y hendiduras branquiales),intravagales, aórtico-simpáticos y autonómicos-viscerales. Los paragangliomas cervicocefálicos pertenecen principalmente a las 2 primeras de estas familias. El presente capítulo está divido en 2 partes. En la primera parte se hace una revisión sobre su origen embriológico, poniendo especial énfasis en el proceso de neurulación o formación del tubo neural; la neurosegmentación, resumiendo los mecanismos implicados en la segmentación inicial del tubo neural y la segmentación del rombencéfalo y la médula espinal, y la evolución de las placodas sensitivas e inducciones secundarias en la región craneal. Posteriormente, se analiza la cresta neural, con especial atención a la cresta neural craneal, para terminar con la embriogénesis de los paragangliomas. En la segunda parte se desarrolla la distribución topográfica de los paragangliomas cervicocefálicos, diferenciándolos conforme a su localización: yúgulo-timpánicos, orbitarios, intercarotídeos, subclavios y laríngeos. Cada tipo se asocia con su embriogénesis y con los detalles anatómicos más relevantes (AU)

Paragangliomas are tumors that arise in the extra adrenalparaganglia and result from migration of neural crest cells during embryonic development. Based on their anatomical distribution, innervation and microscopic structure, these tumors can be classified into interrelated families: branchiomeric paraganglia (related to the branchial clefts and arches), intravagal, aortic-sympathetic and visceral-autonomic. Head and neck paragangliomas belong mainly to the first two of these families. The present article is divided into two parts. The first part reviews the embryological origin of these tumors. Special emphasis is placed on the process of neurulation or neuraltube formation, neurosegmentation (with a summary of the mechanisms involved in the initial segmentation of the neuraltube and of the hindbrain and spinal medulla), and the development of the sensory placodes and secondary inductions in the cranial region. Subsequently, the neural crest is analyzed, with special attention paid to the cranial neuralcrest. The embryonogenesis of paragangliomas is also described. The second part describes the topographical distribution of head and neck paragangliomas according to their localization: jugulotympanic, orbit, intercarotid, subclavian and laryngeal. The embryonogenesis and most important anatomical characteristics are described for each type (AU)