Paraneoplastic cushing’s syndrome: A diagnostic and therapeutic challenge: A case report and literature review

Ectopic Cushing syndrome (ECS) is difficult to diagnose and has a poor prognosis. We report a case of a 44-year-old male who was admitted for clinical suspicion of Cushing’s syndrome. The investigations confirmed the diagnosis of ECS. No tumor was detected in preliminary imaging tests. Then, the octreoscan showed a fixation in a suspect lung node in the middle lobe. The patient was treated initially with medical drugs, he underwent a right middle lobectomy, and yet histopathology did not reveal any nodule. However, the outcome was the healing of our patient. We reviewed published articles to access new diagnostic techniques or advantages in the treatment regimen and a prognosis of ECS. Keywords: ectopic cushing’s syndrome; paraneoplastic syndromes; lung cancer.

Mesenteric Variceal Haemorrhage and Ectopic Cushing’s Syndrome as Presenting Features of a Pancreatic Neuroendocrine Tumour Recurrence

Pancreatic neuroendocrine tumours can have varied and complex presentations. Whilst hormone hypersecretion often induces characteristic clinical syndromes, non-specific symptoms may arise due to localized tumour effects. Malignant invasion of local vasculature is an increasingly recognized complication of these neoplasms and can be associated with significant morbidity. Herein, we present the case of a 47-year-old male with a recurrence of a pancreatic neuroendocrine tumour who presented with unusual upper gastrointestinal bleeding. The tumour had recurred within the superior mesenteric vein, replacing the vessel and invading its branches. This resulted in porto-mesenteric hypertension and the formation of bleeding mesenteric varices. The patient subsequently developed progressive metabolic disturbances and was diagnosed with ectopic Cushing’s syndrome, despite his primary tumour having been non-functional. This case demonstrates not only a rare pattern of tumour recurrence but also the potential for pancreatic neuroendocrine tumours to de-differentiate and change from non-functional to hormone secreting, a phenomenon which may complicate diagnosis and management.

Ectopic Cushing’s Syndrome Secondary to Metastatic Paraganglioma

Paraneoplastic or ectopic Cushing’s syndrome (CS) is a rare cause of endogenous hypercortisolism. It is due to ectopic adrenocorticotropic hormone (ACTH) secretion and has been reported in association with a variety of neuroendocrine tumors such as small-cell lung carcinoma, carcinoid tumors, and medullary carcinoma of the thyroid. Paragangliomas (PGLs) are rare neuroendocrine tumors that can secrete catecholamines. Case reports and reports of ectopic ACTH secretion from metastatic PGLs causing CS are exceedingly rare. We present a case of a 38-year-old female, who presented with typical signs, symptoms, and complications of CS, secondary to a PGL with widespread metastases, which eventually led to her demise.

Occult Carcinoid Causes Cushing’s Syndrome

Introduction: Lung neuroendocrine tumors (NETs) are a common cause of ectopic ACTH-secretion. Only 3% of NETs cause Cushing’s syndrome1; the majority are small and may be radiographically occult. Additionally, the responses to dexamethasone, metyrapone, and oCRF can be indistinguishable from that observed in pituitary Cushing’s disease2. These challenges lead to misdiagnosis and unnecessary procedures. Case Description: 45-year-old male presented for resection of right-sided pulmonary carcinoid tumor. He was diagnosed with Cushing’s syndrome in 2011 when he experienced uncontrolled hypertension and excessive weight gain with elevations in cortisol and ACTH levels. He underwent transsphenoidal pituitary resection in May 2011 for a possible pituitary microadenoma. Post-operative worsening hypertension, weight gain, and striae led to bilateral adrenalectomy in November 2011, complicated by retroperitoneal hemorrhage and resuscitation-induced pulmonary edema. On chest CT in early 2012, an 8 mm incidental right pulmonary nodule was documented. 8 years later, chest imaging for mild COVID-19 infection again revealed a right-sided pulmonary nodule. He underwent CT-guided biopsy of the nodule in July 2020 with pathology demonstrating carcinoid histology. Right lower lobectomy was performed. Pre-operative ACTH was 1673 pg/mL (normal: 10-60 pg/mL) and post-operative ACTH was 16 pg/mL. The resected tumor stained positive for ACTH, confirming that carcinoid tumor was the source of Cushing’s for the past decade. Conclusion: The diagnosis of ectopic Cushing’s syndrome can be elusive, leading to surgeries with significant morbidity, as seen in our patient. In one retrospective review, 14% of patients with Cushing’s had transsphenoidal resection before they were diagnosed with an ectopic source3. Ectopic Cushing’s syndrome can be a challenging diagnosis to make and a multidisciplinary approach with close collaboration between endocrinologist, radiologist, surgeon and pathologist may increase the diagnosis accuracy. Citations: 1Kamp, K, Alwani, R A, Korpershoek, E, Franssen, G., de Herder, W W, & Feelders, R A. (2016). Prevalence and clinical features of the ectopic ACTH syndrome in patients with gastroenteropancreatic and thoracic neuroendocrine tumors, European Journal of Endocrinology, 174(3), 271-280. Retrieved Jan 15, 2021, from https://eje.bioscientifica.com/view/journals/eje/174/3/271.xml 2Malchoff CD, Orth DN, Abboud C, Carney JA, Pairolero PC, Carey RM. Ectopic ACTH syndrome caused by a bronchial carcinoid tumor responsive to dexamethasone, metyrapone, and corticotropin-releasing factor. The American Journal of Medicine. 1988;84(4):760-764. doi:10.1016/0002-9343(88)90116-7 3Ioannis Ilias, David J. Torpy, Karel Pacak, Nancy Mullen, Robert A. Wesley, Lynnette K. Nieman,Cushing’s Syndrome Due to Ectopic Corticotropin Secretion: Twenty Years’ Experience at theNational Institutes of Health, The Journal of Clinical Endocrinology & Metabolism, Volume 90, Issue8, 1 August 2005, Pages 4955–4962, https://doi.org/10.1210/jc.2004-2527