Riedel's Thyroiditis in an Elderly Male Patient: A Rare Entity.

Riedel's thyroiditis (RT) is a rare fibrosclerotic infiltrative thyroid disorder of unclear aetiology. It has been reported in 0.06% of thyroid surgeries and is more common in women. A 60-year-old euthyroid male presented with thyroid swelling and sinus discharge since three years, associated with pain and fever. Near total thyroidectomy revealed right lobe measuring 5x2.5x2 cm, well encapsulated, firm to hard with resistance on cutting. Microscopic examination showed variable sized colloid filled follicles with intervening areas of dense fibrosis admixed with lymphocytic aggregates and perivascular fibrosis extending to the thyroid capsule. The diagnosis of Riedel's thyroiditis was made on histopathological examination. Hence, we would like to emphasize that Riedel's thyroiditis requires diagnostic thyroidectomy and histopathological examination for confirmation.