Psammoma bodies in a benign thyroid gland: A case report and brief review of the literature

Psammoma bodies (PBs) are round, layered calcified structures usually associated with papillary thyroid cancer and may be observed in 40-50% of cases, but may rarely occur in benign thyroid disease. The present study describes a rare case of PBs being found in a benign thyroid gland. In addition, a brief review of the literature is presented. A 28-year-old female patient presented with a 3-month history of weight loss, poor appetite and generalized weakness. Her thyroid was firm and mildly enlarged. Thyroid function was within normal limits (thyroid-stimulating hormone, 0.85 µIU/ml; free T4, 20.1 pmol/l; thyroglobulin, 6.15 ng/ml). An ultrasound demonstrated bilateral TI-RADS-3 nodules measuring 25x21x19 mm (right) and 17x15x13 mm (left). A total thyroidectomy revealed thyroid follicular nodular disease with focal lymphocytic thyroiditis and PBs, but no malignancy. In the literature, 4 cases of PBs or psammomatous calcifications linked to benign conditions were identified, 2 males and 2 females. Half of the cases involved the thyroid-region lesions and half were pediatric (2/4). All cases underwent surgical excision, and fine-needle aspiration was diagnostic in only 1 case (25%). A computed tomography scan was used in 2 cases (50%). A histological analysis confirmed PBs or psammomatous calcifications in every case, and all patients had favorable outcomes with no recurrence upon follow-up. When PBs are detected without tumor cells, submitting the entire thyroid tissue for histology is recommended to rule out microscopic carcinoma. PBs can arise in benign thyroid follicular nodular disease, mimicking malignancy on imaging and cytology, accurate diagnosis requires comprehensive histopathological evaluation.