RESUMO
BACKGROUND: Papillary thyroid carcinoma (PTC) is the most frequent endocrine cancer and most common thyroid cancer. The concurrent occurrence of both tumors however is a very rare occasional finding. Surgical treatment via excision is the only definitive. Our study aims to highlight a rare occurrence of concurrent parathyroid adenoma and micropapillary thyroid carcinoma. CASE PRESENTATION: We describe a 36-year-old female who presented to the outpatient clinic with a left thyroid nodule. Both a Tc-99m-MIBI parathyroid scan and Tc-99m thyroid scan were performed. A left total thyroidectomy was performed then subsequently the parathyroid adenoma was localized. Intra-operative parathyroid hormone decreased by >50 % from 531.5 pg/ml iPTH Stat to 39.8 pg/ml iPTH Stat which is diagnostic for proper localization. Two specimens were sent for histopathological evaluation. Histopathological evaluation of the first specimen confirmed the diagnosis of parathyroid adenoma. Histopathological evaluation of the second specimen revealed that the presence of papillary microcarcinoma of a size of 0.8 cm and pathologic staging to be pT1a, pNx, pMx. CONCLUSION: To our knowledge, this is the first case of concurrent occurrence of parathyroid adenoma and micropapillary thyroid carcinoma reported in the Kingdom of Saudi Arabia. Intraoperatively, management was done by via excision and confirmation of the parathyroid localization was done via intraoperative parathyroid hormone level measurement. We recommend more extensive studies to identify any possible patterns or predictors of finding these two concurrent tumors.