Endocrine Abstracts

Background: The combination of various endocrine tumours is presented both as hereditary syndromes and sporadic forms. Medullary thyroid cancer and prolactinoma are neuroendocrine tumours, the presence of these two pathologies simultaneously has not been previously described in the literature.

Objective: To present a clinical case of a patient with giant prolactinoma and medullary thyroid cancer.

Materials and Methods: To describe the clinical case of a 67-year old patient with giant prolactinoma and medullary thyroid cancer.

Case presentation: The results of magnetic resonance imaging of the cervical spine dated in 2022 revealed an endo-infra-ante-latero(D)sellar pituitary adenoma with the size of 43×22×31 mm. Laboratory tests were as follows: prolactin 94340 mEd/l (60-355), bioactive prolactin 90360 mEd/l (50-300), calcitonin 1340 pg/ml (0-11.8). The patient was initiated on cabergoline therapy. Calcium, parathormone and parathyroid glands - without pathology. US examination of the thyroid gland showed nodules: in the right lobe a moderately reduced echogenicity mass with single fluid inclusions, with clear contours, p.2.1×1.9×1.1 cm (EU-TIRADS 4), and isoechogenic mass with fluid zones d 0.1 cm (EU-TIRADS 2). Cytogram corresponded a C-cell carcinoma, based on the criteria of the classification system of Bethesda V. A flush from the puncture needle for calcitonin showed concentration of 2000 pg/ml on the right and 705 pg/ml on the left, and a calcium gluconate test was performed. At the 3rd and 5th minute, the calcitonin level was >2000 pg/ml, which indicates a high risk of medullary cancer. The results of computed tomography of the chest revealed a peripheral mass in S8 of the right lung and single small foci in the lungs that require dynamic monitoring. Computed tomography of abdominal organs did not reveal any masses. A right-sided hemithyroidectomy was performed, and the results of the morphological examination showed medullary cancer in the right lobe of the thyroid gland, classified as pT1bN1aMx R0 Pn0 LV0. Family history was negative for diseases of the pituitary gland, thyroid gland, oncopathology and other endocrine diseases.

Conclusions: The occurrence of pituitary tumor in combination with thyroid cancer is rare. According to a literature search, this is the first described clinical case of a prolactinoma and a medullary thyroid cancer. It is necessary to expand the spectrum of possible combinations of different neuroendocrine tumours and to perform additional screening.