Background

Differentiating the etiology of ACTH-dependent Cushing’s syndrome (CS) has remained challenging due to the limited accuracy of noninvasive assays. Nowadays, bilateral inferior petrosal sinus sampling (BIPSS) with corticotropin-releasing hormone (CRH) is the gold standard method in the diagnostic work-up of complex CS. However, this method is as yet far from being widespread. The limited utility of this method could be due to many factors such as limited availability of an experienced interventionist, limited availability of CRH, and cost of the procedure. So far, very few studies have been conducted using desmopressin instead of CRH. In this study, we report the use of BIPSS with desmopressin as a diagnostic tool in a series of patients with suspected Cushing’s disease (CD) and equivocal imaging in a tertiary referral center in Iran.

Methods

A total of 13 patients with ACTH-dependent CS and no significant lesions in their pituitary MRI participated in this retrospective case series. All patients underwent BIPSS with desmopressin, and, following centralization of CS, transsphenoidal surgery (TSS) was carried out and diagnosis of CD was confirmed using standard methods.

Results

Of the 13 patients with confirmed CD (by pathology or biochemical response after surgery), eight (61.5%) were female, with a median age of 32 years (IQR: 26–41). The median duration of disease was 24 months (IQR: 11–48). During BIPSS, all patients had a central-to-peripheral gradient greater than 2 under basal conditions. This central-to-peripheral gradient did not increase to > 3 after desmopressin administration in two of these patients. Based on the gradient after BIPSS, the sensitivity of this modality in the diagnosis of CD was 100%. Eight of the 13 patients had right lateralization in both BIPSS and TSS; therefore, the accuracy rate of lateralization by BIPSS was 61.5%. No complications occurred after BIPSS, the exception being the development of groin hematoma in one patient.

Conclusion

No significant benefits of adding desmopressin to BIPSS were observed. The sensitivity of BIPSS in the diagnosis of CD was high, whereas it has moderate accuracy in tumor lateralization.

中文翻译：

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使用去氨加压素对双侧岩下窦取样评估伊朗促肾上腺皮质激素依赖性库欣综合征的病例系列。

背景

由于非侵入性检测的准确性有限，区分 ACTH 依赖性库欣综合征 (CS) 的病因仍然具有挑战性。如今，使用促肾上腺皮质激素释放激素 (CRH) 进行双侧岩下窦取样 (BIPSS) 是诊断复杂 CS 的金标准方法。然而，这种方法还远未普及。这种方法的效用有限可能是由于许多因素造成的，例如经验丰富的干预者的可用性有限、CRH 的可用性有限以及程序成本。到目前为止，很少有研究使用去氨加压素代替 CRH。在这项研究中，我们报告了在伊朗三级转诊中心使用 BIPSS 和去氨加压素作为一系列疑似库欣病 (CD) 和影像学不明确的患者的诊断工具。

方法

共有 13 名 ACTH 依赖性 CS 且垂体 MRI 无明显病变的患者参与了该回顾性病例系列。所有患者都接受了 BIPSS 和去氨加压素，并在 CS 集中后，进行了经蝶窦手术 (TSS)，并使用标准方法确认了 CD 的诊断。

结果

在确诊 CD 的 13 名患者中（根据手术后病理学或生化反应），8 名（61.5%）为女性，中位年龄为 32 岁（IQR：26-41）。疾病的中位持续时间为 24 个月（IQR：11-48）。在 BIPSS 期间，所有患者在基础条件下的中枢至外周梯度均大于 2。在其中两名患者中施用去氨加压素后，这种中央到外周梯度没有增加到 > 3。根据 BIPSS 后的梯度，该模式诊断 CD 的敏感性为 100%。13 名患者中有 8 名在 BIPSS 和 TSS 中均出现右侧化；因此，BIPSS 偏侧化的准确率为 61.5%。BIPSS 后没有出现并发症，唯一的例外是一名患者出现腹股沟血肿。

结论

未观察到向 BIPSS 添加去氨加压素的显着益处。BIPSS在CD诊断中的敏感性较高，而在肿瘤偏侧化方面的准确性中等。