Topuz Özge Vural, Erhan Selma Sengiz, Erinç Sadife Rüya, Tamam Müge Öner
Department of Nuclear Medicine, Prof Dr Cemil Tascioglu City Hospital, Istanbul, Turkey.
Department of Pathology, Prof Dr Cemil Tascioglu City Hospital, Istanbul, Turkey.
Indian J Nucl Med. 2022 Apr-Jun;37(2):186-188. doi: 10.4103/ijnm.ijnm_152_21. Epub 2022 Jul 8.
Papillary thyroid carcinoma (PTC) is the most frequent type of differentiated thyroid cancers (DTCs) and commonly metastasizes to regional lymph nodes. Distant metastases of DTC typically occur in the lungs and bones. Liver metastases of DTC are very rare and difficult to diagnose. We present a case of a 52-year-old woman who had a previous history of PTC treated by total thyroidectomy and lymph node dissection. The patient received two radioactive iodine-131 (I-131) treatments. The second postradioiodine therapy whole-body scan (WBS) revealed intense iodine uptake in the neck region and in the lungs. After 2 months, during the follow-up period, increase in serum thyroglobulin (Tg) level was detected. Positron-emission tomography-computed tomography (PET-CT) with 18F-fluorodeoxyglucose (FDG) revealed increased FDG uptake in the mass lesion that invaded the muscles in the neck area, lung, bone, and liver. The uptake in liver was interpreted as suspicion of malignancy. The trucut biopsy of the liver masses demonstrated metastases of the thyroid carcinoma with the immunohistochemical thyroid transcription factor-1 and PAX8 positivity observed in these tumor cells. In DTC patients with progressive rapid rise of Tg level, the diagnostic value of I-131 WBS will decrease as the differentiation of the tumor decreases. The combined use of I-131 WBS and FDG PET-CT as diagnostic modalities in these patients will be important in treatment planning in detecting locoregional or distant metastases, especially in patients with negative diagnostic I-131 WBS.
乳头状甲状腺癌（PTC）是分化型甲状腺癌（DTC）中最常见的类型，通常转移至区域淋巴结。DTC的远处转移通常发生在肺和骨。DTC的肝转移非常罕见且难以诊断。我们报告一例52岁女性，既往有PTC病史，接受了全甲状腺切除术和淋巴结清扫术。该患者接受了两次放射性碘-131（I-131）治疗。第二次碘治疗后全身扫描（WBS）显示颈部区域和肺部有强烈的碘摄取。2个月后，在随访期间，检测到血清甲状腺球蛋白（Tg）水平升高。18F-氟脱氧葡萄糖（FDG）正电子发射断层扫描-计算机断层扫描（PET-CT）显示，侵犯颈部肌肉、肺、骨和肝脏的肿块病变中FDG摄取增加。肝脏中的摄取被解释为怀疑恶性肿瘤。肝脏肿块的粗针活检显示甲状腺癌转移，在这些肿瘤细胞中观察到免疫组化甲状腺转录因子-1和PAX8阳性。在Tg水平进行性快速升高的DTC患者中，随着肿瘤分化程度降低，I-131 WBS的诊断价值也会降低。在这些患者中，联合使用I-131 WBS和FDG PET-CT作为诊断方法对于检测局部或远处转移的治疗计划很重要，尤其是对于I-131 WBS诊断为阴性的患者。
