[Table/Fig-4]:

a) H&E staining in 28 weeks foetus, showing follicles lined by columnar cells (black arrow), dark stained colloid and vesicles in the colloid. Parafollicular cells are seen as cells with lightly stained nucleus, both, singly in intrafollicular location (green arrow) and in groups of two to three in interfollicular location (red arrow) (Scale bar 1 cm=15 μm [40X]); b) Immunostaining with anticalcitonin in 28 weeks foetus, showing immunopositive parafollicular cells. Red arrow indicates intrafollicular location and green arrow indicates interfollicular location of parafollicular cells near a blood vessel. Immunopositivity is mainly seen in intrafollicular location (scale bar 1 cm=15 μm [40X]).