A synchronous presentation of thyroid follicular carcinoma-like renal tumor and papillary vesicular thyroid tumors: About an exceptional case and review of the literature

Introduction: Thyroid follicular renal cell carcinoma is a special type of renal cell carcinoma newly recognized in recent years. The data is not mature due to the rarity of cases. The association of vesicular papillary tumors of the thyroid is exceptional, and this is the first publication describing such an association in the literature. Case presentation: We present the case of a patient who consulted for a goiter. The definitive pathological examination of the specimen of the thyroidectomy showed papillary vesicular thyroid tumors. A month later, she presented with total hematuria; the CT scan revealed a left renal mass; the patient underwent a partial nephrectomy; and the definitive pathological examination of the specimen showed a thyroid follicular carcinomalike renal tumor. Discussion: Thyroid-type follicular cell renal cell carcinomas are currently recognized as a distinct entity whose histological appearance is reminiscent of thyroid vesicular lesions. There are currently around 39 cases in the literature, but no concomitant thyroid localization has been observed. This finding cannot be verified in the absence of a systematic histological study of the thyroid gland. Our case invites discussion of other thyroid investigation modalities, in particular the value of thyroid biopsy versus cytopuncture, which is often inconclusive in this type of situation. Conclusion: At present, understanding of TFCLRT is still very limited. Even more so, their association with a thyroid tumor is exceptional in the literature. We need to increase the number of cases and conduct in-depth investigations with longer follow-up periods to better understand the situation.