Morphometric study of human thyroid gland with emphasis on pyramidal lobe – a cadaver based study on eastern indian population

Introduction: This study deals with the histo-morphometric study of human thyroid glands, with emphasis on pyramidal lobe. Materials & Methods : 102 formalin preserved cadavers were dissected and Thyroid Glands (65 male and 37 female) were studied. The specimens were studied for the extent and dimensions of lobes, isthmus and the number, extent and attachment of both the PL and levator glandulae thyroideae (LGT). Multiple sections of the PL at different levels were studied histologically with Hematoxylin & Eosin. Results : Right lobe of thyroid gland was slightly larger in males on all aspects while the left lobe was almost equal in both genders. The size of right lobe of thyroid gland in males increased with age, in vertical aspect, while in females the findings were exactly opposite. The isthmus were slightly wider and shorter in males. PL was seen in 22% cases with non-elderly male preponderance, with left sided predominance(75%). LGT was seen in 11.7% cases, arising from apex of PL. Histologically, all the PL had thyroid follicles in various sections, made from base to apex. Discussion : This study highlights the extents & measurements of lobes and isthmus of human thyroid glands to facilitate the screening using radiological tools. Moreover, PL is more prevalent in males with its origin from the left lobe of thyroid gland mainly. Thyroid follicles are a constant finding in this lobe, which makes it more matter of concern for the oncologists and head-neck surgeons.