The Unforeseen Diagnosis: Hyperparathyroidism-Jaw Tumour Syn
Hypercalcemia and its systemic sequelae are a relatively common finding amongst patients in the field of endocrinology. Primary hyperparathyroidism, a frequent cause of hypercalcemia, is often seen among middle-aged female patients, typically resulting from an underlying single-gland adenoma. Although patients may present with symptoms (nephrolithiasis, musculoskeletal discomfort, dehydration, or mood disturbance, to name a few), hypercalcemia is rather frequently identified incidentally. In younger patients, a familial form of primary hyperparathyroidism must be considered, with a positive diagnosis mandating familial screening. Hyperparathyroidism-jaw tumor syndrome is one such autosomal dominant familial disorder, characterized by a mutation in the cell division cycle 73 (CDC73; also known as HRPT-2) tumor suppressor gene.

This disorder is characterized by multiple pleiotropic phenomena, including recurrent primary hyperparathyroidism (and the effects of hypercalcemia), neoplasms (such as uterine, renal, mandibular, and maxillary), and infertility. A patient not conforming to the classic candidacy for primary hyperparathyroidism requires consideration for a familial cause. Although a rare diagnostic entity, hyperparathyroidism-jaw tumor syndrome must be considered in early-onset, familial, atypical, or recurrent primary hyperparathyroidism. Genetic analysis is the gold standard for confirming the diagnosis, and patients must be continually monitored and reassessed to detect recurrence and other systemic manifestations of the disorder. Surgical treatment is the favored approach to managing primary hyperparathyroidism, and all family members must be screened for the genetic mutation.

With the myriad of phenotypes displayed by hyperparathyroidism-jaw tumor syndrome, patients may initially present to departments other than endocrinology or metabolic medicine, including obstetrics and gynecology (for infertility), urology (for renal stones), or maxillofacial (for jaw tumors).