Synchronous Parathyroid Carcinoma and Noninvasive Follicular Thyroid Neoplasm With Papillary-Like Nuclear Features

Abstract

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism. Compared to parathyroid adenoma, parathyroid cancer is more likely to be associated with marked levels of serum parathyroid hormone (PTH) and hypercalcemia with severe clinical manifestations. Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) is a rare variant of papillary thyroid cancer. Here, we report the case of a middle-aged woman who presented with multiple fractures and neck swelling. Neck ultrasound and fine-needle aspiration cytology revealed a provisional diagnosis of thyroid carcinoma. Parathyroid and bone scan were performed because of primary hyperparathyroidism and hypercalcemia and established the diagnosis of hyperfunctioning right-sided parathyroid tumor. Right parathyroidectomy and total thyroidectomy were performed, and the histopathological report confirmed the diagnosis of parathyroid carcinoma and NIFTP. The synchronic coexistence between parathyroid cancer and thyroid neoplasms is an extremely rare condition that prompted us to report this case.

Keywords: niftp; parathyroid carcinoma; primary hyperparathyroidism; thyroid carcinoma; total thyroidectomy.

Figure 1. Parathyroid scan.

(A) Initial images of the thyroid gland using Tc-pertechnetate shows an irregular accumulation of the tracer in the region of the left lobe of the thyroid (arrow). (B) The To-MIBI parathyroid images show a large irregular area of ​​accumulation of the tracer in the region of the right thyroid lobe (arrow). (C-G) Accumulation of the tracer in the right thyroid lobe remains the same on the delayed images (arrow). MIBI: methoxyisobutyl isonitrile

Figure 2. Neck ultrasound.

(A) Right lobe lesion (TI-RADS 4): moderately suspicious lesion with size more than 1.5 cm. (B) Left lobe lesion (TI-RADS 3): mildly suspicious lesion with size more than 2.5 cm. TI-RADS: Thyroid Imaging Reporting and Data System

Figure 3. Histopathological features of the parathyroid lesion.

(A) Parathyroid lesion with fibrous capsule, many broad fibrous septa are dividing the tumor into multiple lobules (H&E, 10×). (B) Extensive areas of necrosis, hemosiderin-laden macrophages, and cholesterol clefts are noted within the mass (H&E, 20×). (C) Tumor lobules are composed of nests of clear cells with an admixture of eosinophilic cells (H&E, 20×). H&E: hematoxylin and eosin

Figure 4. Immunohistological features of the parathyroid lesion.

The tumor cells are positive for chromogranin and GATA3 (strong and diffuse) and negative for all thyroid markers such as thyroglobulin, TTF-1, and PAX-8 (H&E, 20×). GATA3: GATA binding protein; TTF-1: thyroid transcription factor 1; PAX-8: paired-box gene 8; H&E: hematoxylin and eosin

Figure 5. Histopathological features of the thyroid lesion.

(A) The thyroid nodule is composed of micro and macrofollicles lined by follicular epithelial cells showing patchy nuclear clearing, overlapping, nuclear membrane irregularities, and pleomorphism (H&E, 10×). (B) No definitive intranuclear inclusions noted in the section studied. No vascular or capsular invasion seen. No papilla, necrosis, or solid areas noted (H&E, 10×). H&E: hematoxylin and eosin