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.