Μυελοειδές καρκίνωμα θυρεοειδούς σαν τυχαίο εύρημα μετά από λοβεκτομή

THYROGLOSSAL DUCT CYST (TGDC): EMBRYOLOGY - PATHOPHYSIOLOGY

Embryological formation of the thyroid gland begins at the foramen cecum of the tongue. During the 4^th week of gestation, a ventral diverticulum of the foramen cecum is formed, which – with its narrow neck connected to the tongue - descends in the midline of the neck, where the thyroid lobes separate, by the 7^th week. The path of descent is usually anterior to the hyoid bone, but may be posterior or through the bone. Typically, the tract atrophies and disappears by the 10^th week of gestation. However, portions of the tract and thyroid parenchyma remnants associated with it may persist at any point between the tongue and the thyroid.

TGDC is formed as a cystic expansion of a remnant of the thyroglossal duct tract. It is believed that lymphoid tissue associated with the tract hypertrophies following a regional infection, thereby occluding the tract with resultant cyst formation. The incidence of TGDCs is ~ 7 % (autopsy studies).