Role of parathyroid hormone measurement in fine-needle aspiration biopsy washout in diagnosis and treatment of primary hyperparathyroidism

In this article, we discuss difficulties in parathyroid localization modalities in diagnosis of primary hyperparathyroidism. Most often, superior parathyroid glands are located on the posteromedial surface of the right and left lobes of the thyroid gland, however, they also could be found at the carotid bifurcation, behind pharynx and esophagus, as well as inside thyroid gland. Location of the inferior parathyroid glands is more variable: on the side or back surface, or below the lower pole of the thyroid gland, as well as in thymus, posterior or anterior mediastinum, or inside thyroid. Localization modalities of primary hyperparathyroidism are based on neck ultrasonography, scintigraphy with sestamibi, computed tomography of neck and mediastinum. In cases with combination of multinodal goitre and an intrathyroid location of the parathyroid gland, there might be additional difficulties in verification of various patterns (thyroid nodules or parathyroid glands). In this article, we present two clinical cases of intrathyroid location of parathyroid glands. The algorithm of parathyroid adenoma localization is shown. Determination of PTH level in washing liquid after fine-needle aspiration biopsy from necessary punctures of the nodule formations, which can be either intrathyroid parathyroid glands or thyroid nodules, can also help to avoid diagnostic mistakes.