A rare form of the thyroid gland cancer against the background of autoimmune thyroiditis

Background: Sclerosing mucoepidermoid carcinoma of the thyroid gland was first reported in 1991. This type of a tumor may develop in connection with Hashimoto's thyroiditis. There are two variants of mucoepidermoid carcinoma of the thyroid gland: the normal and sclerosing types. Sclerosing mucoepidermoid carcinoma of the thyroid gland has recently been recognized by the World Health Organization as a separate disease. Сlinical case description: We present a clinical case of a 51-year-old woman who was observed for 2 years for autoimmune thyroiditis with nodulation. The patient had no symptoms or signs of compression. The level of thyroid–stimulating hormone was 15.8 (range 0.4–4.0), the level of antibodies to peroxidase was 150 IU/ml. Thyroid scintigraphy revealed a dominant cold node (1.5×2 cm) in the right lobe of the gland. During the control ultrasound examination of the neck, negative dynamics was observed, then a fine needle aspiration biopsy of the thyroid node was performed. A follicular tumor was found against the background of Hashimoto's thyroiditis, which was the reason for a timely treatment. In the described case, the patient underwent a total thyroidectomy without neck lymph node dissection, no postoperative radiotherapy or other auxiliary treatments were performed. A full-body scintigraphy showed no recurrence of the disease in 10 months after the initial treatment. Conclusion: Given the rarity of the disease and the impossibility to differentiate it from other thyroid tumor’s, a more thorough examination of the nearby lymphatic collectors is necessary to exclude metastatic lesions, and in the presence of altered lymph nodes, additional diagnosis by fine-needle aspiration biopsy with subsequent determination of the scope of surgical treatment and postoperative management of this category of patients is indicated.