Recurrent hyperparathyroidism caused by benign neoplastic seeding: two cases of parathyromatosis and a review of the literature.

Background: Parathyromatosis is defined as small nodules of hyperfunctioning parathyroid tissue scattered in the soft tissues of the neck and/or mediastinum. Parathyromatosis may be primary, it may be aimed for when autotransplanting parathyroid tissue in secondary hyperparathyroidism, and it may occur after surgery for primary hyperparathyroidism (pHPT). In the latter cases parathyromatosis poses a diagnostic and therapeutic challenge.

Methods: To illustrate the clinical problem of parathyromatosis as a rare cause of recurrent disease after an operation for pHPT we describe two patients and performed a review of the literature for contributing factors.

Results: Two patients, previously treated for pHPT and having undergone multiple neck explorations had at their final operation numerous small nests of benign parathyroid tissue scattered throughout connective tissue of the neck. These findings concur with various previous cases reported in the reviewed literature.

Conclusions: These cases illustrate that meticulous handling of parathyroid adenomas during surgical excision is of the utmost importance. Regardless of which operating technique is utilised, great emphasis must be placed on precautions towards ensuring the complete and above all the intact removal of the affected gland without capsular rupture. As parathymatosis is caused by seeding, which although extremely rare, it might very well result in the need for extensive reexploration.