Endocrine Unit, Department of Medical Therapeutics, Alexandra Hospital, Athens University School of Medicine, 80, Vas Sofias ave, 11528, Athens, Greece.
Endocrine. 2013 Dec;44(3):610-5. doi: 10.1007/s12020-013-9961-7. Epub 2013 Apr 23.
Medullary thyroid carcinoma (MTC) is a rare tumour which frequently occurs in the context of the multiple endocrine neoplasia syndromes, where it coexists with other usually benign tumours. The clinical picture varies and distant metastases are frequently present at diagnosis. Calcitonin levels are elevated in the presence of metastatic disease. Two MTC cases are presented, which had elevated postoperative calcitonin levels. Imaging revealed lung lesions which were originally attributed to metastatic disease from the MTC. However, at follow-up, these cases presented unusual features. The rapid increase in the lung lesions and the development of hypercalcaemia in the first patient suggested a second unrelated tumour. Biopsy of the lung lesion was compatible with lung adenocarcinoma. In the second patient, the appearance of a liver mass, although calcitonin levels remained stable, led to biopsy of the lesion: this was negative for calcitonin and compatible with metastatic lung adenocarcinoma. These MTC cases show that further malignancies may coexist with MTC and may obscure the clinical picture and influence the therapeutic decisions, especially in the case of metastatic disease. Features such as unusual imaging characteristics and the development of hypercalcemia, never encountered in MTC outside the MEN2 syndromes, as well as 'disproportionately' low calcitonin levels, incompatible with extensive metastatic disease, were the factors that led to further work-up. Both the cases subsequently proved to carry an unsuspected second malignancy. It is crucial to discriminate the metastatic lesion attributed to MTC from another coexisting primary malignancy, because different therapeutic strategies are needed for each setting.
甲状腺髓样癌（MTC）是一种罕见的肿瘤，常发生在多发性内分泌肿瘤综合征的背景下，与其他通常为良性的肿瘤并存。临床表现多样，诊断时常伴有远处转移。降钙素水平在转移性疾病存在时升高。本文报告了 2 例 MTC 患者，术后降钙素水平升高。影像学显示肺部病变，最初归因于 MTC 的转移性疾病。然而，在随访中，这些病例出现了不寻常的特征。第一例患者肺部病变迅速增加，血钙升高，提示存在第二个无关的肿瘤。肺病变活检与肺腺癌一致。第二例患者肝脏肿块的出现，尽管降钙素水平保持稳定，导致对病变进行活检：降钙素阴性，与转移性肺腺癌一致。这些 MTC 病例表明，进一步的恶性肿瘤可能与 MTC 并存，并可能掩盖临床表现，影响治疗决策，尤其是在转移性疾病的情况下。一些不常见的影像学特征和高钙血症的发生，这些在 MEN2 综合征之外的 MTC 中从未遇到过，以及与广泛转移疾病不相称的“不成比例”低降钙素水平，这些都是导致进一步检查的因素。这两个病例随后都证实携带了未被怀疑的第二种恶性肿瘤。区分归因于 MTC 的转移性病变与另一种并存的原发性恶性肿瘤至关重要，因为每种情况下都需要不同的治疗策略。
