Clinical Heterogeneity of Ectopic ACTH Syndrome: A Long-Term Follow-Up Study

Differentiating lung neuroendocrine neoplasms from tumor-like infection using CT in patients with ectopic ACTH syndrome

OBJECTIVES

Pulmonary neuroendocrine neoplasms (NENs) are the most frequent cause of ectopic adrenocorticotropic hormone syndrome (EAS); lung infection is common in EAS. An imaging finding of infection in EAS patients can mimic NENs. This retrospective study investigated EAS-associated pulmonary imaging indicators.

METHODS

Forty-five pulmonary NENs and 27 tumor-like infections from 59 EAS patients (45 NEN and 14 infection patients) were included. Clinical manifestations, CT features, 18F-FDG, or 68Ga-DOTATATE-PET/CT images and pathological results were collected.

RESULTS

High-sensitivity C-reactive protein (p < 0.001) and expectoration occurrence (p = 0.04) were higher, and finger oxygen saturation (p = 0.01) was lower in the infection group than the NENs group. Higher-grade NENs were underrepresented in our cohort. Pulmonary NENs were solitary primary tumors, 80% of which were peripheral tumors. Overlying vessel sign and airway involvement were more frequent in the NENs group (p < 0.001). Multifocal (p = 0.001) and peripheral (p = 0.02) lesions, cavity (p < 0.001), spiculation (p = 0.01), pleural retraction (p < 0.001), connection to pulmonary veins (p = 0.02), and distal atelectasis or inflammatory exudation (p = 0.001) were more frequent in the infection group. The median CT value increment between the non-contrast and arterial phases was significantly higher in NENs lesions (p < 0.001). Receiver operating characteristic curve analysis indicated a moderate predictive ability at 48.3 HU of delta CT value (sensitivity, 95.0%; specificity, 54.1%).

CONCLUSION

Chest CT scans are valuable for localizing and characterizing pulmonary lesions in rare EAS, thereby enabling prompt differential diagnosis and treatment. CRITICAL RELEVANCE STATEMENT: Thin-slice CT images are valuable for the localization and identification of pulmonary ectopic adrenocorticotropic hormone syndrome lesions, leading to prompt differential diagnosis and effective treatment.

KEY POINTS

Lung tumor-like infections can mimic neuroendocrine neoplasms (NENs) in ectopic adrenocorticotropic hormone syndrome (EAS) patients. NENs are solitary lesions, whereas infections are multiple peripheral pseudotumors each with identifying imaging findings. Typical CT signs aid in localization and creating an appropriate differential diagnosis.

Ectopic Hormonal Syndromes: Cushing's Syndrome and Acromegaly

Ectopic hormone production may be present in neuroendocrine and non-endocrine neoplasms. Ectopic sources of growth hormone, adrenocorticotropin (ACTH), or their releasing factors are uncommon but clinically relevant. Ectopic ACTH tumors have been studied more than the rest, but there are still no comprehensive multidisciplinary guidelines that include all the pitfalls in the diagnosis and management of ectopic hormonal syndromes and the neoplasms associated with ectopic Cushing or acromegaly. The frequency of neuroendocrine neoplasms and other neoplasms with neuroendocrine differentiation has been increasing in recent decades. The review of the available data on these tumors, their classification, and improvements in diagnostic and therapeutic procedures is important to understand the relevance of ectopic Cushing's syndrome and acromegaly in clinical practice.

An Overlooked Manifestation of Hypercortisolism: Cerebral Cortical Atrophy and Challenges in Identifying the Etiology of Hypercortisolism - A Report of 2 Pediatric Cases

INTRODUCTION

Endogenous Cushing's syndrome (CS) is a rare, severe disease that can cause multiple systemic involvements and behavioral problems due to excessive cortisol production. Structural changes can be noted in the brain magnetic resonance imaging (MRI) scans of these cases.

CASES

A 9-year-old girl and a 13-year-old boy were admitted with hypercortisolism. In the female patient, altered consciousness was prominent along with cerebral and cerebellar brain atrophy, and findings indicating posterior reversible encephalopathy syndrome were detected in the brain MRI. Although the male patient's neurological examination was normal, significant cerebral atrophy was seen in the brain MRI. Case 1 was diagnosed as having ectopic ACTH syndrome (EAS) due to a thymic carcinoid tumor. Case 2 underwent a pulmonary lobectomy upon detection of a bronchial lesion in the Ga-68 DOTATATE PET/CT scan while being examined for EAS due to a lack of suppression in the high-dose dexamethasone suppression test. However, hypercortisolism persisted despite the removal of the bronchial lesion, and subsequently, a diagnosis of Cushing's disease was established following bilateral inferior petrosal sinus sampling.

DISCUSSION

Endogenous hypercortisolism may cause brain atrophy of varying severity. The central nervous system findings can be overlooked in children with CS. More comprehensive studies are needed to better understand the behavioral changes caused by the effects on the brain and to evaluate whether these changes are reversible. In addition, identifying the source of hypercortisolism can be difficult due to a lack of experience related to the rarity of the disease in children.

Case report: Radiofrequency ablation combined with biopsy for Cushing's syndrome due to ectopic ACTH lesions in the lung

Lung carcinoid tumor is one of the major tumors causing ectopic ACTH syndrome, and the most common clinical treatment is surgical resection of the lesion. We herein report a suspected pulmonary carcinoid tumor with difficulty in surgical resection and poor response to drug therapy, which was successfully treated with radiofrequency ablation combined with intraoperative biopsy of the lesion. A 48-year-old female patient, with hypercortisolism (reddening of the face, full moon face, hirsutism, acne, and weight gain) detected three months ago. Small and high-dose dexamethasone suppression tests were not suppressed, Cushing's syndrome was under consideration. PET-CT examination suggested mild FDG uptake in two nodules in the anterior basal segment of the lower lobe of the right lung, the possibility of ectopic ACTH lesions was considered because of the clinical presentation. Due to difficult surgical approach of the lesion, high risk of surgery and the patient's anxiety, CT-guided thermal ablation combined with puncture biopsy was considered to treat the lesions. Image-guided thermal ablation can effectively inactivate ectopic ACTH lesions in the lung, rapidly improve the symptoms of high cortisol, and can be combined with biopsy for pathologic diagnosis. Therefore, this technique can be considered for treating pulmonary ACTH lesions that are difficult to resect surgically.

Clinical and laboratory characteristics and results of treatment of patients with ACTH-producing neuroendocrine tumors of various localization

Aim. To study the clinical, biochemical characteristics, treatment results and follow-up of patients with ectopic ACTH syndrome EAS (ACTH adrenocorticotropic hormone ). Materials and methods. A retrospective, observational, single-center study of 130 patients with EAS. Demographic information of patients, medical history, results of laboratory and instrumental investigations at the pre- and postoperative stages and follow-up of EAS were analyzed. Results. The mean age at the diagnosis ranged from 12 to 74 years (Me 40 years [28; 54]). The duration of the disease from the onset of symptoms to the verification of the diagnosis varied from 2 to 168 months (Me 17.5 months [7; 46]). Eighty-one (62,3%) patients had bronchopulmonary NET, 9 thymic carcinoid, 7 pancreatic NET, 5 pheochromocytoma, 1 cecum NET, 1 appendix carcinoid tumor, 1 medullary thyroid cancer and 25 (19.2%) had an occult source of ACTH. The median follow-up period of patients was 27 months [9.75; 61.0] with a maximum follow-up of 372 months. Currently, primary tumor was removed in 82 (63.1%) patients, bilateral adrenalectomy was performed in 23 (18%) patients, in 16 of them there was an occult source of ACTH-producing NET and in 7 patients in order to control hypercortisolism after non-successful surgical treatment. Regional and distant metastases were revealed in 25 (19.2%) patients. At the time of the last observation 59 (72%) patients were exhibited a full recovery, 12 (14.6%) had relapse of the disease and 26 (20%) died from multiple organ failure (n=18), pulmonary embolism (n=4), surgical complications (n=2), disseminated intravascular coagulation syndrome (n=1) or COVID-19 (n=1). Conclusion. In our cohort of patients bronchopulmonary NET are the most frequent cause of EAS (62.3%). Surgical treatment leads to remission of hypercortisolism in 72% cases; the proportion of relapse (14.6%) and fatal outcome (20%) remains frequent in EAS.

Case Report: Three Rare Cases of Ectopic ACTH Syndrome Caused by Adrenal Medullary Hyperplasia

Ectopic ACTH syndrome (EAS) accounts for 10-20% of endogenous Cushing's syndrome (CS). Hardly any cases of adrenal medullary hyperplasia have been reported to ectopically secrete adrenocorticotropic hormone (ACTH). Here we describe a series of three patients with hypercortisolism secondary to ectopic production of ACTH from adrenal medulla. Cushingoid features were absent in case 1 but evident in the other two cases. Marked hypokalemia was found in all three patients, but hyperglycemia and osteoporosis were present only in case 2. All three patients showed significantly elevated serum cortisol and 24-h urinary cortisol levels. The ACTH levels ranged from 19.8 to 103.0pmol/L, favoring ACTH-dependent Cushing's syndrome. Results of bilateral inferior petrosal sinus sampling (BIPSS) for case 1 and case 3 confirmed ectopic origin of ACTH. The extremely high level of ACTH and failure to suppress cortisol with high dose dexamethasone suppression test (HDDST) suggested EAS for patient 2. However, image studies failed to identify the source of ACTH secretion. Bilateral adrenalectomy was performed for rapid control of hypercortisolism. After surgery, cushingoid features gradually disappeared for case 2 and case 3. Blood pressure, blood glucose and potassium levels returned to normal ranges without medication for case 2. The level of serum potassium also normalized without any supplementation for case 1 and case 3. The ACTH levels of all three patients significantly decreased 3-6 months after surgery. Histopathology revealed bilateral adrenal medullary hyperplasia and immunostaining showed positive ACTH staining located in adrenal medulla cells. In summary, our case series reveals the adrenal medulla to be a site of ectopic ACTH secretion. Adrenal medulla-originated EAS makes the differential diagnosis of ACTH-dependent Cushing's syndrome much more difficult. Control of the hypercortisolism is mandatory for such patients.