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 277 pg/mL and calcium level at 10.8 mg/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.