Case Report: A Challenging Localization of a Pulmonary Ectopic ACTH-Secreting Tumor in a Patient With Severe Cushing’s Syndrome

Abstract

BackgroundEctopic adrenocorticotropic syndrome (EAS) is a rare cause of endogenous ACTH-dependent Cushing’s syndrome, usually associated with severe hypercortisolism as well as comorbidities. Tumor detection is still a challenge and often requires several imaging procedures. In this report, we describe a case of an ectopic ACTH secretion with a misleading localization of the responsible tumor due to a concomitant rectal carcinoma.Case presentationA 49-year-old man was referred to our Endocrinology Unit due to suspicion of Cushing’s syndrome. His medical history included metastatic rectal adenocarcinoma, diagnosed 5 years ago and treated with adjuvant chemotherapy, radiotherapy and surgical resection. During follow-up, a thoracic computed tomography scan revealed two pulmonary nodules located in the superior and middle lobes of the right lung with a diameter of 5 and 10 mm, respectively. However, these nodules remained radiologically stable thereafter and were not considered relevant. All biochemical tests were suggestive of EAS (basal ACTH levels: 88.2 ng/L, nv 0–46; basal cortisol levels: 44.2 µg/dl, nv 4.8–19.5; negative response to CRH test and high dose dexamethasone suppression test) and radiological localization of the ectopic ACTH-secreting tumor was scheduled. The CT scan revealed a dimensional increase of the right superior lung nodule (from 5 to 12 mm). [68Ga]-DOTA-TOC PET/CT scan was negative, while [18F]-FDG-PET/CT showed a tracer accumulation in the superior nodule. After a multidisciplinary consultation, the patient underwent thoracic surgery that started with two atypical wedge resections of nodules. Frozen section analyses showed a neuroendocrine tumor on the right middle lobe nodule and a metastatic colorectal adenocarcinoma on the superior lesion. Then, a right superior nodulectomy and a right middle lobectomy with mediastinal lymphadenectomy were performed. The final histopathological examination confirmed a typical carcinoid tumor, strongly positive for ACTH. A post-surgical follow-up showed a persistent remission of Cushing’s syndrome.ConclusionsThe present report describes a case of severe hypercortisolism due to EAS not detected by functional imaging methods, in which the localization of ACTH ectopic origin was puzzled by a concomitant metastatic rectal carcinoma. The multidisciplinary approach was crucial for the management of this rare disease.

Radioisotope diagnostics of endogenous ACTH-dependent hypercorticism: a review

“…По результатам исследований чувствительность этого метода составляет 50-51,7% [30,50]. В то же время некоторые клинические случаи демонстрируют преимущество ПЭТ/КТ с 18 F-ФДГ в обнаружении АКТГ-продуцирующей опухоли, не экспрессирующей соматостатиновые рецепторы по данным сцинтиграфии с мечеными аналогами соматостатина [51], а также ПЭТ/КТ с 68 Ga-DOTA-TOК [52] и 68 Ga-DOTA-ТАТЕ [53].…”

An Ectopic Acth-Secreting Tumour After Adrenalectomy for Primary Aldosteronism

“…Cushing's syndrome is a rare disorder caused by chronic hypercortisolism with multisystem morbidity, increased mortality and decreased quality of life 1,2 . An ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is an infrequent form of endogenous ACTH-dependent Cushing's syndrome [1][2][3] , usually associated with intense hypercortisolism [1][2][3][4] , as well as severe comorbidities such as hypokalemia, diabetes mellitus, infections and vertebral fractures [1][2][3][6][7][8][9] . EAS is a rare condition, responsible for about 5-20% of all Cushing syndrome cases and 10-20% of ACTH-dependent Cushing syndrome patients [1][2][3][4][9][10][11][12] .…”

“…An ectopic adrenocorticotropic hormone (ACTH) syndrome (EAS) is an infrequent form of endogenous ACTH-dependent Cushing's syndrome [1][2][3] , usually associated with intense hypercortisolism [1][2][3][4] , as well as severe comorbidities such as hypokalemia, diabetes mellitus, infections and vertebral fractures [1][2][3][6][7][8][9] . EAS is a rare condition, responsible for about 5-20% of all Cushing syndrome cases and 10-20% of ACTH-dependent Cushing syndrome patients [1][2][3][4][9][10][11][12] . The first time when EAS was named and largely studied was in the early 1960s by Liddle and soon after by Meador 13,14 .…”

Immune function of colon cancer associated miRNA and target genes

“…Diagnosing colon cancer can be challenging due to the atypical early symptoms, which often go unnoticed by patients, resulting in delayed diagnosis and treatment, poor surgical outcomes, and missed opportunities for surgical intervention ( 1 , 2 ). Tumor immunotherapy has emerged as a promising new approach for treating colon cancer ( 3 ).…”