Huhle cells seen in ?

Ans. is `b' i.e., Hashimoto ThyroiditisPathological features of Hashimoto's thyroiditis 1. Cross featuresDiffuse symmetrically enlarged thyroidAlthough the gland is symmetrically enlarged, the accentuation of lobulations may make the gland appear lobular on gross examination.Capsule is intactCut surface is pale, yellow firm and lobulated.2. Microscopic featuresAtrophy of thyroid follicles (atrophic follicles)Extensive lymphoplasmocytic infiltrate with abundant small lymphocytes and plasma cells with destruction of follicles.Oncocytic metaplasia (Huhle cell metaplasia) - The surviving follicular epithelial cells are commonly transformed into large cells with abundant pink cytoplasm and are known as Huhle cells.Oncocytic metaplasia (Huhle cell metaplasia) is also known "oxyphilic change" in epithelial cells and is considered the hallmark of Hashimoto's thyroiditis.Varying degree of fibrosis and foci of squamous metaplasia within atrophic follicles.Interstitial connective tissue is increased and may be abundant.