Unusual Cytoplasmic Inclusion Bodies in Medullary Carcinoma of the Thyroid

Abstract

Medullary Thyroid Carcinoma(MTC) was first described by Hazard et al. and it is known to be C-cell origin and one of the members of APUDomas. Recently we have studied ultrastructural characteristics of 17 cases of MTC and this report describesultrastructural features of an unusual case in which 4 types of cytoplasmic inclusions other than typical secretory granules and ordinary cytoplasmic organelle were observed. The clinical and histologic features of this case were typical of the MTC and the patient was treated with Co radiation 90 days prior to the surgery. Small pieces of the tumor tissues(lymph node metastasis) obtained from 43 year-old male patient at total thyroidectomy and left modified neck disection were prepared for transmission electron microscopy by standard methods.