Occult parathyroid carcinoma in a patient with papillary thyroid carcinomaand Hashimoto's thyroiditis

A 47-year-old female patient with a previous history of right thyroid lobec tomy was admitted to the hospital because of a 3 cm nodule in the thyroid g land. Hormonal evaluation showed subclinical hypothyroidism with serum leve ls of thyroid stimulating hormone slightly elevated to 4.4 mug/dl (normal: 0.4-4 mug/dl). Thyroid ultrasound showed diffuse irregularity of the gland and the presence of a solitary nodule (30x18 mm in diameter) localized in t he left lobe. A fine needle aspiration biopsy was performed. Cytological an alysis revealed papillary thyroid carcinoma and Hashimoto's thyroiditis. To tal thyroidectomy was performed. During the operation, two of the parathyro id glands were detected to be hyperplastic. Histopathological examination o f the thyroid and parathyroid glands revealed Hashimoto's thyroiditis with papillary thyroid carcinoma and synchronous carcinoma of the parathyroid gl and. To our knowledge, this association of occult parathyroid carcinoma in a patient with papillary thyroid carcinoma and Hashimoto's thyroiditis has not been reported in the literature. Given the high prevalence of autoimmun e diseases in elderly women, a random occurrence of this triad represents t he most likely explanation. (C) 2001, Editrice Kurtis.