Abstract：
BACKGROUND: Follicular thyroid carcinomas (FTCs) rarely metastasize to regional lymph nodes, and descriptions of synchronous lateral lymph node metastases of FTC and papillary thyroid carcinoma (PTC) are lacking.
METHODS: We describe a 43-year-old female with a preoperative cytology indicating a right-sided PTC with lateral lymph node metastases. She underwent a total thyroidectomy and central and lateral lymph node dissection, and histopathology confirmed a multifocal tall cell variant PTC together with a 12 mm minimally invasive FTC in the ipsilateral lobe. While the central compartment demonstrated metastatic PTC, the lateral compartment contained PTC metastases alongside a 15 mm large follicular-patterned mass in a separate lymph node. As the cells lacked PTC associated nuclear changes, the possibility of a lateral lymph node metastasis of FTC was considered, with the possibility of ectopic thyroid tissue as a differential diagnosis. By utilizing next-generation sequencing, a Q61R NRAS mutation was pinpointed, thus proving the tissue as tumorous. The patient underwent radioiodine treatment and is currently monitored following a negative whole-body scan.
CONCLUSIONS: This is probably the first case report of a patient with co-existing lateral lymph node PTC and FTC metastases. Consulting previous publications, there is currently a gap of knowledge in terms of how patients with regional FTC metastases should be followed-up and treated, especially when co-occurring with spread high-risk PTC subtypes. Moreover, what guides a seemingly indolent FTC to spread via the lymphatic system remains to be defined from a molecular standpoint.
METHODS: We describe a 43-year-old female with a preoperative cytology indicating a right-sided PTC with lateral lymph node metastases. She underwent a total thyroidectomy and central and lateral lymph node dissection, and histopathology confirmed a multifocal tall cell variant PTC together with a 12 mm minimally invasive FTC in the ipsilateral lobe. While the central compartment demonstrated metastatic PTC, the lateral compartment contained PTC metastases alongside a 15 mm large follicular-patterned mass in a separate lymph node. As the cells lacked PTC associated nuclear changes, the possibility of a lateral lymph node metastasis of FTC was considered, with the possibility of ectopic thyroid tissue as a differential diagnosis. By utilizing next-generation sequencing, a Q61R NRAS mutation was pinpointed, thus proving the tissue as tumorous. The patient underwent radioiodine treatment and is currently monitored following a negative whole-body scan.
CONCLUSIONS: This is probably the first case report of a patient with co-existing lateral lymph node PTC and FTC metastases. Consulting previous publications, there is currently a gap of knowledge in terms of how patients with regional FTC metastases should be followed-up and treated, especially when co-occurring with spread high-risk PTC subtypes. Moreover, what guides a seemingly indolent FTC to spread via the lymphatic system remains to be defined from a molecular standpoint.
摘要：
背景：滤泡性甲状腺癌（FTC）很少转移到区域淋巴结，缺乏对FTC和甲状腺乳头状癌（PTC）的同步外侧淋巴结转移的描述。
方法：我们描述了一名43岁的女性，其术前细胞学检查显示右侧PTC伴外侧淋巴结转移。她接受了甲状腺全切除术和中央和外侧淋巴结清扫术，组织病理学证实了同侧肺叶的多灶性高细胞变异型PTC和12mm微创FTC。虽然中央隔室显示转移性PTC，侧室包含PTC转移灶，并在单独的淋巴结中存在15毫米大的滤泡样肿块。由于细胞缺乏PTC相关的核变化，考虑了FTC侧方淋巴结转移的可能性，与异位甲状腺组织作为鉴别诊断的可能性。通过利用下一代测序，一个Q61RNRAS突变被精确定位，从而证明组织是肿瘤。患者接受了放射性碘治疗，目前在阴性全身扫描后进行监测。
结论：这可能是首例同时存在侧侧淋巴结PTC和FTC转移的患者。咨询以前的出版物，目前，在FTC区域转移患者应如何随访和治疗方面存在知识差距，特别是与传播的高风险PTC亚型同时发生时。此外，从分子的角度来看，是什么引导看似惰性的FTC通过淋巴系统传播仍有待定义。
方法：我们描述了一名43岁的女性，其术前细胞学检查显示右侧PTC伴外侧淋巴结转移。她接受了甲状腺全切除术和中央和外侧淋巴结清扫术，组织病理学证实了同侧肺叶的多灶性高细胞变异型PTC和12mm微创FTC。虽然中央隔室显示转移性PTC，侧室包含PTC转移灶，并在单独的淋巴结中存在15毫米大的滤泡样肿块。由于细胞缺乏PTC相关的核变化，考虑了FTC侧方淋巴结转移的可能性，与异位甲状腺组织作为鉴别诊断的可能性。通过利用下一代测序，一个Q61RNRAS突变被精确定位，从而证明组织是肿瘤。患者接受了放射性碘治疗，目前在阴性全身扫描后进行监测。
结论：这可能是首例同时存在侧侧淋巴结PTC和FTC转移的患者。咨询以前的出版物，目前，在FTC区域转移患者应如何随访和治疗方面存在知识差距，特别是与传播的高风险PTC亚型同时发生时。此外，从分子的角度来看，是什么引导看似惰性的FTC通过淋巴系统传播仍有待定义。
