Synchronous Occurrence of Papillary, Follicular, and Medullary Carcinoma in the Same Thyroid Gland

Abstract

Incidence of thyroid carcinoma has increased dramatically; however, simultaneous occurrence of different tumors in a single thyroid gland is rare and the embryologic or molecular explanations for such cases lack a solid basis. We report on a 67-year-old woman who underwent surgery for cytologically undetermined nodules in the bilateral thyroid glands. Postoperative pathology findings indicated synchronous occurrence of discrete papillary, follicular, and medullary thyroid carcinoma. She has remained disease-free after postoperative radioactive iodine therapy (130 mCi). This is the fifth report on the synchronous occurrence of different tumors in a single thyroid gland worldwide, and the first ever in Asia.

Synchronous occurrence of papillary thyroid microcarcinoma, medullary thyroid carcinoma and Hashimoto thyroiditis in a single thyroid: A case report with literature review

“…Regardless of the fact that the frequency of thyroid cancer has increased significantly in recent years, the concomitant occurrence of multiple tumors in a single thyroid gland is still a rare occurrence [12] . Synchronous existence of these two neoplasms can occur in two forms: distinct MTC and PTC isolated by normal thyroid tissue, or mixed medullary and follicular-derived thyroid carcinoma, in which single or multiple lesions show morphology and immunoreactivity for both MTC and follicular-derived carcinoma (PTC) [13] .…”

“…The first is the “common stem cell theory,” which is based on the fact that follicular and parafollicular C-cells have common progenitor cells. According to this view, common stem cells initially undergo neoplastic transformation before being differentiated into the two separate cell subtypes [12] . Another hypothesis is the “field effect theory,” which claims that a shared oncogenic signal causes both follicular and parafollicular C-cell progenitor cells to change at the same time [12] .…”

“…According to this view, common stem cells initially undergo neoplastic transformation before being differentiated into the two separate cell subtypes [12] . Another hypothesis is the “field effect theory,” which claims that a shared oncogenic signal causes both follicular and parafollicular C-cell progenitor cells to change at the same time [12] . Other possible explanations for the simultaneous occurrence include the involvement of the RET proto-oncogene in both PTC and MTC, whether through a point mutation (in MTC) or a gene rearrangement (in PTC) [15] .…”