Difficulties of diagnostics of parothoid adenoma in the background of combined treatment of advanced thyroid cancer

In clinical practice, the most common sporadic variant of solitary parathyroid adenoma. Atypical adenomas of the parathyroid glands are a rare form and present the greatest difficulty in determining the potential for malignancy, the extent of surgical treatment, and the patient’s dynamic follow-up regimen. They are not characterized by the classic signs of malignant growth – invasion beyond the formation capsule or the presence of metastases. Specific clinical and prognostic phenotypes of parathyroid adenomas are highly individual.

No more than 3% of parathyroid adenomas are associated with papillary thyroid cancer. Awareness of such a combination of pathology allows us to assess possible risks and determine the scope of surgical intervention as the only method of radical treatment of pathologically altered parathyroid tissue. With early detection of recurrence of thyroid cancer, it is necessary to conduct additional monitoring of hormonal activity and radiation diagnosis of tumor pathology of the parathyroid glands.

The presented clinical case showed that the cytological and histological diagnosis of parathyroid adenoma against the background of recurrence of advanced thyroid cancer can fundamentally differ at different stages of the morphological study. With parathyroid adenoma in the preoperative period, there may be a discrepancy between these methods of radiation and intraoperative diagnostics and the results of an urgent and planned histological examination. The uncharacteristic course of solitary parathyroid adenoma after thyroidectomy in combination with false positive results due to ultrasound location of thyroid nodules (residual tumors and cancer recurrences, as well as paratracheal metastases) and nervous tissue (paraganglioma) contributes to incorrect preoperative diagnosis of thyroid bed tumors. At the preoperative stage of diagnosing tumor pathology of the parathyroid glands, it is advisable to perform scintigraphy of the parathyroid glands with a simultaneous combination of ultrasound, which will increase the sensitivity of the diagnosis.

After surgical treatment of tumor pathology of the parathyroid tissue, in some cases, the result of differential diagnosis is an immunohistochemical study to form a final diagnosis and determine further patient management tactics.