甲状腺神经内分泌癌引起促肾上腺皮质激素依赖性库欣综合征。

Department of Endocrinology and Metabolism, Institute of Post-Graduate Medical Education and Research and Seth Sukhlal Karnani Memorial Hospital, Kolkata, India.

Thyroid. 2013 Jan;23(1):120-3. doi: 10.1089/thy.2012.0027.

BACKGROUND

Cushing's syndrome (CS) due to ectopic adrenocorticotrophic hormone (ACTH) and/or ectopic corticotropic releasing hormone (CRH) secretion accounts for <10% of all CS. Neuroendocrine carcinomas rarely cause CS. These carcinomas have been found to secrete either ACTH or rarely CRH. Herein we report a case of neuroendocrine carcinoma originating from the thyroid as the source of ACTH-dependent CS.

SUMMARY

A 30-year-old woman with features of CS presented with severe respiratory distress. Six months before that, she was diagnosed with primary hypothyroidism and started on levothyroxine (LT4) therapy. Biochemical evaluation was done, and nonsuppressed serum cortisol levels following dexamethasone with high ACTH confirmed a diagnosis of ACTH-dependent CS. Magnetic resonance imaging of the brain showed a bulky pituitary gland. Adrenal imaging showed bilateral adrenal hyperplasia. A computerized tomography scan showed a large anterior mediastinal mass arising from the neck and extending behind the transverse aortic arch. She underwent emergency thoracotomy due to rapidly progressive superior mediastinal syndrome and left vocal cord palsy. At surgery, the mass was seen originating from the thyroid and the thymus was compressed posteriorly. Near total thyroidectomy and thymectomy with removal of pericardial seedlings were done. Histopathology revealed sheets, cords, and nests of round or oval tumor cells with hyperchromatic nuclei and scant cytoplasm with local invasion and lymphovascular embolization suggestive of a neuroendocrine carcinoma arising from thyroid, staining positive for cytokeratin, synaptophysin, and chromogranin-A, and negative for calcitonin and carcinoembryonic antigen.

CONCLUSIONS

Here we report a case of a neuroendocrine tumor of the thyroid causing ACTH-dependent CS. The tumor was negative for calcitonin staining, indicating that this was not a medullary carcinoma of the thyroid. Neuroendocrine carcinomas originating from the thyroid gland are very rare. A thyroid tumor of neuroendocrine origin causing ACTH-dependent CS has not been reported previously.

背景

由异位促肾上腺皮质激素（ACTH）和/或异位促皮质素释放激素（CRH）分泌引起的库欣综合征（CS）占所有 CS 的<10%。神经内分泌癌很少导致 CS。这些癌已被发现分泌 ACTH 或很少分泌 CRH。在此，我们报告了一例源自甲状腺的神经内分泌癌，为 ACTH 依赖性 CS 的来源。

总结

一名 30 岁女性出现 CS 特征，表现为严重呼吸窘迫。六个月前，她被诊断为原发性甲状腺功能减退症，并开始服用左甲状腺素（LT4）治疗。进行了生化评估，地塞米松后未抑制的血清皮质醇水平和高 ACTH 证实诊断为 ACTH 依赖性 CS。脑磁共振成像显示垂体肿大。肾上腺成像显示双侧肾上腺增生。计算机断层扫描显示前纵隔大肿块，起源于颈部并延伸至主动脉弓后。由于纵隔综合征迅速进展和左侧声带麻痹，她接受了紧急开胸手术。手术中，肿块起源于甲状腺，胸腺被向后压迫。行近全甲状腺切除术和胸腺切除术，并切除心包苗。组织病理学显示圆形或椭圆形肿瘤细胞呈片状、条索状和巢状排列，核深染，细胞质稀少，伴有局部浸润和血管淋巴管栓塞，提示甲状腺起源的神经内分泌癌，对细胞角蛋白、突触素和嗜铬粒蛋白 A 染色阳性，对降钙素和癌胚抗原染色阴性。