endemic goiter, light micrograph

endemic goiter thyroid histology microscopy medical pathology gland enlargement tissue microscope scientific health disease examination diagnosis endocrinology microscopic iodine deficiency thyroxine histopathology condition disorder nodules nodular hyperplasia follicular cells colloid iodinerich hormones glandular endocrine system follicles histological illustration cellular structure dysfunction research anatomical micrograph light photomicrograph