Coexistence of papillary and medullary thyroid carcinoma: A rare entity

Abstract

The coexistence of different types of thyroid carcinomas is rather unusual. It has been considered coincidental and lin-ked to the growing incidence of papillary thyroid carcinoma (PTC). This paper presents a case of multifocal PTC and coe-xistent medullary thyroid carcinoma (MTC) distinct from each other, along with PTC lymph node metastasis. The 44-year-old female patient underwent subtotal thyroidectomy with a pre-operative diagnosis of multinodular goiter. Histo-logical reports revealed PTC in the right lobe and PTC beside a tumoral area morphologically suspicious for MTC in the left thyroid lobe. Immunohistochemistry confirmed the diagnosis of MTC. Post-operative ultrasound and subsequent fine needle aspiration biopsy revealed lymph node metas-tases of PTC in the right anterior cervical area. Comple-mentary thyroidectomy, central neck dissection, and right modified neck dissection were carried out with subsequent I-131 ablation therapy. In conclusion, the biological behavi-ors and prognoses of MTC and PTC are different. Therefore, the entity demands a different clinical approach in treatment and follow-up.