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.