Autoimmune thyroiditis a fibrous variant of Hashimoto's thyroiditis: A rare case

Hashimoto thyroiditis (HT) is an autoimmune disorder characterized by inadequate thyroid hormone production. A fibrous variant is one of the rarest entities of Hashimoto's thyroiditis disease. A 42 -year-old female patient presented to our service with neck swelling associated with difficulty swallowing; she was discovered to have an enlarged thyroid gland with mass effect. She underwent an ultrasound and fine-needle aspiration (FNA), which was consistent with Hashimoto's thyroiditis -Bethesda category II-. Due to compressive symptoms, we proceeded to total thyroidectomy. The final histopathology revealed numerous polymorphic lymphoid cells, plasma cells, follicular cells, and scattered Hürthle cells, characteristic of fibrous variants. The surgery was complicated with voice hoarseness and hypocalcemia, which was managed successfully with corticosteroids and calcium supplements. The mainline treatment of HT is medical, but surgical intervention can be considered in some cases. A multidisciplinary approach is needed for successful management. Continuous patient monitoring post-operatively is vital to detect and intervene with early surgical complications. •Hashimoto thyroiditis is the commonest autoimmune disease with a 10% fibrous variant.•The gold-standard investigation modality is tissue histopathology.•THYROID CANCER is the most serious differential to be ruled out as the patients usually present with symptoms mimicking thyroid cancer.•The mainstay of treatment of such cases is medical, surgery can be considered in case of compressive symptoms and cosmetics reasons.•Extensive fibrosis may result in intra-operative difficulties, good pre-operative preparation and close post-operative observation is vital for good outcome.