Parathyroid Gland Histopathology M-2 P.E. Wakely, Jr., M.D. Department of Pathology Wexner Medical Center

Parathyroid Gland - Objectives Describe the embryology & histology of the parathyroid glands. Define the etiology and clinical features of hyper- and hypo-parathyroidism. Recognize the distinction between parathyroid hyperplasia and parathyroid adenoma.

Parathyroid Glands Derived from pharyngeal pouches Inferior glands from 3 rd pouch Superior glands from 4 th pouch Typically 4 glands – 2 on each side Cell Types: Chief cells: pale or clear cytoplasm Oxyphil cells: eosinophilic cytoplasm mg. each Two major diseases: hyper- and hypo- PTH

Ivar Sandström, MD y/o medical student Uppsala Hospital Discoverer of parathyroid glands Suicide, age 37 yrs.

Normal parathyroid

Primary HyperParathyroidism  serum PTH levelMobilized Ca ++   serum Ca ++,  serum P Etiology: adenoma – 80% hyperplasia – 15-20% carcinoma – <1 % Clinical Manifestations F:M = 4:1; yrs. renal calculi / weakness/fatigue / osteoporosis / bone resorption [osteitis fibrosa cystica] mental status change, seizures

Fig Parathyroid hyperplasia. All four glands are enlarged, albeit not to the same extent. Parathyroid hyperplasia

Capt C. Martell 1926 the first parathyroidectomy performed in the USA. Over several yrs. had 6 operations in neck for hyperparathyroidism 7 th operation: found tumor in mediastinum. Cured hyperPTH Died 6 weeks later from hypocalcemic- induced hypoparathyroidism.

PTH Adenoma

Parathyroid adenoma

PTH Adenoma

PTH Adenoma, Oxyphilic Type

PTH Adenoma

PTH Adenoma, Clear Cell Type

h % 5-15%

HypoParathyroidism  serum Ca ++ Etiology inadvertent surgical removal, congenital absence, idiopathic atrophy Clinical manifestations tetany [neuromuscular irritability numbness  laryngospasm, seizures] mental status changes, cardiac conduction disturbances: prolongation QT interval

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