Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor of parafollicular C cells. The majority of MTCs occur sporadically, but about 30% of the cases are associated with multiple endocrine neoplasia type 2 (MEN2) syndrome or familial MTC. Generally, MTCs have no clinical manifestation, but infrequently the patients develop symptoms of hypercortisolism by secreting adrenocorticotropic hormone (ACTH) or corticotropin-releasing hormone (CRH). Although ectopic Cushing syndrome is only found in 0.7% of MTC patients, it can lead to fatal consequences if left untreated. Over 50 cases of MTC-related Cushing syndrome have been reported, and few autopsy cases exist in the literature. In those cases, the tumor cells are positive for calcitonin, but mostly display negative immunostaining for ACTH or CRH. The authors report an autopsy case of a 22-year-old woman who was found dead with no medical history whose cause of death was diabetic ketoacidosis associated with MTC, which showed poor calcitonin stainability.

甲状腺髓样癌（MTC）是一种罕见的滤泡旁C细胞神经内分泌肿瘤。大多数 MTC 为散发性，但约 30% 的病例与多发性内分泌肿瘤 2 型 (MEN2) 综合征或家族性 MTC 相关。一般来说，MTCs没有临床表现，但很少有患者通过分泌促肾上腺皮质激素（ACTH）或促肾上腺皮质激素释放激素（CRH）而出现皮质醇增多症的症状。尽管异位库欣综合征仅在 0.7% 的 MTC 患者中发现，但如果不及时治疗可能会导致致命的后果。已有超过 50 例 MTC 相关库欣综合征的报道，文献中鲜有尸检病例。在这些情况下，肿瘤细胞对降钙素呈阳性，但大多数对 ACTH 或 CRH 免疫染色呈阴性。