Co-occurrence of bilateral intrathyroidal parathyroid gland and papillary thyroid carcinoma; a case report

Intrathyroidal parathyroid is a parathyroid completely embedded within the thyroid parenchyma. The aim of this study is to present a case with co-occurring bilateral normal intrathyroidal parathyroid glands and papillary thyroid carcinoma (PTC).

A 35-year-old female presented with anterior neck swelling for a duration of a week. The patient was generally asymptomatic. Ultrasound showed mild enlargement of the thyroid gland, and a well-defined solid nodule measuring 9 ∗ 8 ∗ 7 mm in the left lobe with malignant characteristics. Laboratory findings were within normal limits. Fine needle aspiration of the nodule resulted in the diagnosis of PTC. The patient underwent total thyroidectomy. Histological examination confirmed the diagnosis of well differentiated multifocal bilateral PTC alongside two bilaterally located intrathyroidal parathyroid glands.

The occurrence of normal ITP is exceedingly rare, and even rarer when simultaneous with other thyroidal lesions. It is theorized that inferior parathyroid glands arise from the third pharyngeal pouch, and during embryogenesis they might migrate to other anatomic locations. In this case, two bilateral normal ITP were present with PTC.

Normal ITP presents a diagnostic challenge due to their high insensitivity to current preoperative diagnostic techniques; hence, surgeons are required to carefully examine thyroid tissue during thyroidectomy when missing parathyroid glands are observed.