A 25-year-old female presented with features of weight gain and loss of appetite and easy fatigue. On examination a swelling was noticed in anterior aspect of neck which moved with deglutination. Biopsy performed from neck revealed the following. What is your diagnosis?

Ans. (b) Hashimoto's thyroiditis*The history given suggests a thyroid swelling. The given biopsy from the same shows thyroid parenchyma containing a dense lymphocytic infiltrate with germinal centers. Residual thyroid follicles are lined by deeply eosinophilic Hurthle cells. This suggests Hashimoto's thyroiditis.