Parathyroid gland hyperplasia associated with tuberculous granulomatous inflammation manifesting as primary hyperparathyroidism.

OBJECTIVES:Inflammatory disorders of the parathyroid gland are poorly defined. Only seven cases of granulomatous infection have been reported in the literature. PATIENTS AND METHODS:A 68-year-old woman presented with parathyroid hormone level at 277pg/mL and calcium level at 10.8mg/dL, considered as primary hyperparathyroidism. Parathyroidectomy was performed, normalizing analytical values. RESULTS:Normal-size gland with chief cell hyperplasia, focal pseudofollicular changes, and presence of epithelioid granulomas with Langhans giant cells and caseous necrosis areas, and a positive PCR for M. tuberculosis complex was identified. Chronic granulomatous inflammation could provoke a cascade of immune system activation, resulting in hyperplasia with the consequent increase in parathyroid function, and therefore primary hyperparathyroidism. CONCLUSIONS:In populations with a high incidence of tuberculosis, the coexistence of these pathologies must be kept in mind. This theory needs further biomolecular studies to be confirmed, but it provides a new perspective within the possible etiologies of hyperparathyroidism.