Marine-Lenhart syndrome combined with papillary thyroid carcinoma: a case report

Background Marine-Lenhart syndrome is a rare clinical condition, and most thyroid nodules combined with Marine-Lenhart syndrome are benign nodules. In this case, Marine-Lenhart syndrome was combined with a malignant nodule and a papillary thyroid carcinoma, which is even rarer. Case presentation: We report a case of Marine-Lenhart syndrome in which the 99m TcO4 scan indicated a “hot nodule” in the thyroid. However, due to the patient’s thyroid ultrasound revealing a TI-RADS 4a categorized nodule, we performed a thyroid fine-needle aspiration biopsy followed by subsequent thyroid lobectomy with isthmusectomy. Both the results of pathological analysis confirmed the presence of papillary thyroid carcinoma. Conclusions After confirming the presence of Graves’ disease, it is still essential to consider the possibility of thyroid hyperfunctioning adenoma, namely Marine-Lenhart syndrome. Although most thyroid nodules associated with Marine-Lenhart syndrome are benign and often present as “hot nodules,” it is crucial not to disregard the small probability of thyroid malignancy in such cases.