Endocrinology and Nutrition Department, Cliniques Universitaires Saint-Luc, n°10, Avenue Hippocrate, 1200, Brussels, Belgium.
Department of Radiology, Cliniques Universitaires Saint Luc, UCLouvain, 1200, Brussels, Belgium.
BMC Endocr Disord. 2023 Feb 16;23(1):43. doi: 10.1186/s12902-023-01298-2.
Ectopic ACTH pituitary adenomas (EAPA), located outside the sella turcica and deriving from cellular remnants of Rathke's pouch are a very rare cause of Cushing's syndrome (CS). The diagnosis is often difficult and delayed, even after comprehensive work-up. To our knowledge, we report for the first time an ectopic corticotroph tumor of the posterior wall of the sphenoid sinus, leading to false positive results of bilateral inferior petrosal sinus sampling (BIPPS) and which was finally localized by a co-registered C Methionine PET/MR imaging.
A 48-year-old woman was referred for a high clinical suspicion of ACTH-dependent CS. Biological testing comprising low dose dexamethasone suppression and CRH stimulation tests were indicative of pituitary Cushing's disease, but comprehensive pituitary MRI did not reveal any pituitary adenoma. BIPSS confirmed however a central origin of ACTH secretion (central-to-peripheral ACTH ratio > 100) and revealed a significant right-to-left gradient (6.2), leading to a first right-sided exploratory hypophysectomy, that did not cure the patient. BIPSS images were reviewed and revealed preferential drainage of the left pituitary to the right petrosal sinus, leading us to a left sided exploratory hypophysectomy, which was again unsuccessful. A C Methionine PET/MRI was performed and revealed a hypermetabolic lesion adjacent to the posterior wall of the sphenoidal sinus. After surgical resection, this polypoid mass was identified as an ectopic ATCH-secreting pituitary adenoma expressing ACTH and T-Pit and complete remission of hypercortisolism was observed.
In conclusion, we report a case of ACTH-dependent Cushing's syndrome, caused by an ectopic corticotroph adenoma located in the sphenoidal sinus, which perfectly mimicked the biological features of a classical pituitary ACTH adenoma on a comprehensive hormonal evaluation including BIPPS, and the features of a benign naso-sinusal polyp at MRI. We report for the first time a key role of C Methionine PET co-registered to high resolution MRI for localizing ectopic adenomas, efficiently guiding surgical removal and leading to complete remission of hypercortisolism.
异位 ACTH 垂体腺瘤（EAPA）位于蝶鞍外，来源于 Rathke 囊的细胞残余，是库欣综合征（CS）的非常罕见原因。即使经过全面检查，诊断也常常很困难且被延误。据我们所知，我们首次报告了一例蝶窦后壁异位促皮质素细胞瘤，导致双侧岩下窦采样（BIPPS）假阳性结果，并最终通过 co-registered C Methionine PET/MR 成像定位。
一名 48 岁女性因高度疑似 ACTH 依赖性 CS 而被转介。包括低剂量地塞米松抑制和 CRH 刺激试验在内的生物学检测提示为垂体库欣病，但全面的垂体 MRI 未发现任何垂体腺瘤。然而，BIPSS 证实 ACTH 分泌的中枢起源（中枢-周围 ACTH 比值>100），并显示出明显的右向左梯度（6.2），导致首次右侧探查性垂体切除术，但未治愈患者。对 BIPSS 图像进行了回顾，并发现左侧垂体向右侧岩下窦的优先引流，导致我们进行了左侧探查性垂体切除术，但再次失败。进行了 C Methionine PET/MRI 检查，发现蝶窦后壁有一个高代谢病变。手术后切除了这个息肉样肿块，被鉴定为异位分泌 ACTH 的垂体腺瘤，表达 ACTH 和 T-Pit，皮质醇增多症完全缓解。
总之，我们报告了一例由位于蝶窦的异位促皮质素腺瘤引起的 ACTH 依赖性库欣综合征病例，该病例在全面的激素评估中，包括 BIPPS，以及在 MRI 上表现为良性鼻-鼻窦息肉的特征，完全模拟了经典垂体 ACTH 腺瘤的生物学特征。我们首次报告了 C Methionine PET 与高分辨率 MRI 联合定位异位腺瘤的关键作用，有效地指导手术切除，并导致皮质醇增多症完全缓解。
