Abstract：
Medullary thyroid cancer (MTC) is a rare disease from parafollicular C cells. Calcitonin has been suggested as a screening; its levels are proportional to the tumor size and predictive of metastatic disease. We present a case where an early action was taken with lower cut-off points. Male patient, 49 years old. Thyroid ultrasound (US) with a suspicious nodule. Fine Needle Aspiration Biopsy (FNAB) suggests MTC, with pre-operative serum calcitonin (CTN) of 591 pg/mL. Total thyroidectomy with central and bilateral dissection was performed. Biopsy: MTC in left nodule of 26 mm without lymph nodes (LN) metastases. Follow-up with undetectable CTN for six years. After that, CT was 4.7 pg/mL, and carcinoembryonic antigen (CEA) was 1.2 ng/mL. Neck US showed bilateral LN. FNAB of LN does not show recurrence. A progressive rise of markers with doubling time of CTN and CEA was 16 and 51.3 months, respectively. CTN raised until 112 pg/mL. Given the lack of cervical compromise, a neck and lung CT, liver MRI, and bone scintigraphy were ordered despite CTN levels < 150 pg/mL. MRI showed hypervascular hepatic lesions, contrasted with gadoxetic acid. PET Ga68-DOTATATE showed lesions with overexpression of somatostatin receptors in the liver. Surgery was done, and a biopsy confirmed metastases. Conclusions: The clinical guidelines may allow the management of cases; however, they should be used considering each case context. In our patient, if the guidelines had been strictly followed, it would not have been possible to detect liver metastases to achieve a surgical resection with curative intent.
摘要：
甲状腺髓样癌（MTC）是由滤泡旁C细胞引起的罕见疾病。降钙素已被建议作为筛查；其水平与肿瘤大小成正比，并可预测转移性疾病。我们提出了一个案例，即在较低的截止点下采取了早期行动。男性患者,49岁。甲状腺超声（US）伴可疑结节。细针穿刺活检（FNAB）提示MTC，术前血清降钙素（CTN）为591pg/mL。进行了中央和双侧解剖的全甲状腺切除术。活检：左侧结节26mmMTC，未见淋巴结（LN）转移。随访6年无法检测到CTN。之后,CT为4.7pg/mL,癌胚抗原（CEA）为1.2ng/mL。颈部US显示双侧LN。LN的FNAB未显示复发。随着CTN和CEA倍增时间的逐渐升高，标志物分别为16和51.3个月，分别。CTN上升至112pg/mL。鉴于宫颈缺乏妥协，颈部和肺部CT,肝脏MRI,尽管CTN水平<150pg/mL，仍订购骨闪烁显像。MRI显示高血管肝脏病变,与gadoxetic酸形成对比。PETGa68-DOTATATE显示肝脏中生长抑素受体过度表达的病变。手术完成了,活检证实有转移.结论：临床指南可能允许病例的管理；然而，他们应该使用考虑每个案例的背景。在我们的病人身上，如果严格遵守准则，我们不可能检测到肝转移以实现具有治愈性的手术切除.
