Anatomy and Histology of the Parathyroid Glands

Rodrigo Arrangoiz MS, MD, FACS, FSSO
  • Most patients have four parathyroid glands
    • The superior glands usually are dorsal to the RLN at the level of the cricoid cartilage
    • The inferior parathyroid glands are located ventral to the nerve
  • Normal parathyroid glands are gray and semitransparent in newborns:
    • But appear golden yellow to light brown in adults:
      • Parathyroid color depends on cellularity, fat content, and vascularity
    • Moreover, they often are embedded in and sometimes difficult to discern from surrounding fat
  • There are normally two pairs of parathyroid glands (inferior and superior)
    • The parathyroid gland is oval or bean-shaped (Figure)
    • It typically measures 6 mm × 4 mm × 2 mm
    • They weigh 40 mg to 60 mg
  • Most people have four parathyroid glands:
    • Akerström et al, in a series of 503 autopsies:
      • Identified four parathyroid glands in 84% of the cases
    • Supernumerary glands were found in 13% of the cases:
      • Most commonly in the thymus
    • In the literature, the incidence of supernumerary glands:
      • Is anywhere between 3% and 13%
  • Only in three percent of the cases less than four parathyroid glands are identified
  • The blood supply of the parathyroid glands:
    • Is usually derived from branches of the inferior thyroid artery:
      • Although branches of the superior thyroid artery can supply at least 10% to 45% of the superior parathyroid glands
    • In a study of 354 autopsy specimens, Alverd, observed:
      • That both the superior and inferior parathyroid glands derive their blood supply from the inferior thyroid artery:
        • 86% on the right side and 77% from the left side
    • When the inferior thyroid artery was absent:
      • Both the superior and inferior parathyroid glands were supplied by the superior thyroid artery
    • Branches from the thyroidea ima, and vessels to the trachea, esophagus, larynx, and mediastinum:
      • May also contribute to the irrigation of the parathyroid glands
  • Wang et al., in a study of 160 autopsy specimens:
    • Showed that a low lying inferior parathyroid gland could be identified by following the vascular pedicle of the inferior thyroid artery
  • The parathyroid glands drain ipsilaterally by the:
    • Superior, middle, and inferior thyroid veins
  • The innervation of the parathyroid glands:
    • Occurs via the superior or middle cervical ganglia, or through a plexus in the fascia on the posterior aspect of the thyroid lobe 
  • Histologically, parathyroid glands are composed of:
    • Chief cells and oxyphil cells arranged in trabeculae, within a stroma composed primarily of adipose cells (Figure)
Normal parathyroid histology showing chief cells interspersed with adipose cells.
  • The parathyroid glands of infants and children:
    • Are composed mainly of chief cells:
      • Which produce parathyroid hormone (PTH)
  • Acidophilic, mitochondria-rich oxyphil cellsL:
    • Are derived from chief cells:
      • Can be seen around puberty:
        • They increase in numbers in adulthood
  • A third group of cells, known as water-clear cells:
    • Also are derived from chief cells
    • Are present in small numbers, and are rich in glycogen
  • Although most oxyphil and water-clear cells retain the ability to secrete PTH:
    • Their functional significance is not known.
Unknown's avatar

Published by Rodrigo Arrangoiz MS, MD, FACS, FSSO

My name is Rodrigo Arrangoiz I am a breast surgeon/ thyroid surgeon / parathyroid surgeon / head and neck surgeon / surgical oncologist that works at Center for Advanced Surgical Oncology in Miami, Florida. I was trained as a surgeon at Michigan State University from (2005 to 2010) where I was a chief resident in 2010. My surgical oncology and head and neck training was performed at the Fox Chase Cancer Center in Philadelphia from 2010 to 2012. At the same time I underwent a masters in science (Clinical research for health professionals) at the University of Drexel. Through the International Federation of Head and Neck Societies / Memorial Sloan Kettering Cancer Center I performed a two year head and neck surgery and oncology / endocrine fellowship that ended in 2016. Mi nombre es Rodrigo Arrangoiz, soy cirujano oncólogo / cirujano de tumores de cabeza y cuello / cirujano endocrino que trabaja Center for Advanced Surgical Oncology en Miami, Florida. Fui entrenado como cirujano en Michigan State University (2005 a 2010 ) donde fui jefe de residentes en 2010. Mi formación en oncología quirúrgica y e n tumores de cabeza y cuello se realizó en el Fox Chase Cancer Center en Filadelfia de 2010 a 2012. Al mismo tiempo, me sometí a una maestría en ciencias (investigación clínica para profesionales de la salud) en la Universidad de Drexel. A través de la Federación Internacional de Sociedades de Cabeza y Cuello / Memorial Sloan Kettering Cancer Center realicé una sub especialidad en cirugía de cabeza y cuello / cirugia endocrina de dos años que terminó en 2016.

Leave a comment