Paraneoplastic Cushing Syndrome in Gastrointestinal Neuroendocrine Tumour

Ectopic production of adrenocorticotropic hormone (ACTH) by gastrointestinal neuroendocrine tumours (NETs) is relatively uncommon. We report a rare case of a liver metastatic G1 low-grade NET of the intestine that induced hypercortisolism after surgical resection. A 50-year-old man was admitted for an intestinal obstruction caused by a tumour of the intestine. Paraneoplastic Cushing syndrome was diagnosed more than a year later following the appearance of cushingoid symptoms, despite stable disease according to RECIST criteria but chromogranin A increase. Ketoconazole and sandostatin medical treatment and liver chemoembolization never managed to control the hypercortisolism unlike the bilateral adrenalectomy. The identification and effective management of this uncommon statement of ectopic ACTH secretion is important to improve the patient’s prognosis and quality of life.

Lung Carcinoid Tumors and Paraneoplastic Cushing's Syndrome: Diagnostic and Therapeutic Difficulties - A Case Report

Introduction. - Paraneoplastic Cushing's syndrome is a rare cause of endogenous hypercorticism. It is caused by ectopic secretion of ACTH by a non-pituitary endocrine tumor. The aetiological biological and radiological data are often inconclusive, which creates a problem of differential diagnosis with Cushing's disease. In addition, these tumors are often small and their location is extremely variable. As a result, the difficulties of localization require the use of specific imaging techniques.Observation. - We report the observation of a 44-year-old man suffering from diabetes and high blood pressure, presenting a severe and rapidly progressive Cushing syndrome, in connection with a hypercorticism caused by an ectopic ACTH secretion. The thoracic computed tomography performed within the framework of a search for a neoplastic origin objectified a 15 mm nodule isolated at the level of the middle lobe, the scintigraphy with octreotide marked with indium-111 found a significant fixation at the level of the lung nodule. The patient had a middle lobe lobectomy. The outcome was favorable with regression of Cushing's syndrome. Pathological examination was in favor of a typical carcinoid tumor, and the immunohistochemical complement showed tumor cell positivity for ACTH, CD56, chromogranin, and synaptophysin.Conclusion. - This observation illustrates the dilemma between the need to locate an ectopic ACTH secretion and the control of aggressive and threatening Cushing's syndrome. Early use of the octreotide scintigraphy should be considered if a topographic diagnosis of the causative tumor cannot be done through conventional imaging techniques.

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

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.

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.

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.

The value of [68Ga]Ga-DOTA-TATE PET/CT in diagnosis and management of suspected pituitary tumors

Background Gallium 68-tetraazacyclododecane-tetraacetic acid-octreotate ([68Ga]Ga-DOTA-TATE) is a selective somatostatin analogue ligand, which shows increased affinity for somatostatin receptor subtype (SSTR) 2 and has been used routinely for imaging neuroendocrine tumors with PET/CT. We investigated the utility of [68Ga]Ga-DOTA-TATE positron emission tomography/computed tomography (PET/CT) in patients with suspected pituitary pathology. We reviewed imaging for twenty consecutive patients (8 men, 12 women, mean age of 48.2, range 14–78) with suspected pituitary pathology who were referred for [68Ga]Ga-DOTA-TATE PET/CT. Results Nine patients presented with recurrent Cushing’s syndrome following surgical resection of pituitary adenomas due to recurrent Cushing’s disease (seven patients) and ectopic ACTH secreting tumor (2 patients). All seven patients with recurrent Cushing’s disease showed positive pituitary [68Ga]Ga-DOTA-TATE uptake while both cases of ectopic hormonal secretion had absented pituitary uptake. In 1 of these 2 patients, [68Ga]Ga-DOTA-TATE was able to localize the source of ectopic ACTH tumor. Six patients presented de novo with Cushing’s due to ectopic ACTH secretion; [68Ga]Ga-DOTA-TATE PET/CT was able to localize ectopic tumors in six of eight patients (3 lungs, 2 pancreases, 1 mid-gut) There was high uptake [68Ga]Ga-DOTA-TATE in 3 cases of recurrent central hyperthyroidism (SUVmax 6.6–14.3) and 2 cases of prolactinoma (SUVmax 5.5 and 11.3). Conclusion Absent [68Ga]Ga-DOTA-TATE activity in the pituitary fossa is useful in excluding pituitary disease in recurrent Cushing’s. Recurrent pituitary thyrotropinomas and prolactinomas showed moderate to high pituitary activity. In addition, in Cushing’s syndrome, [68Ga]Ga-DOTA-TATE is useful for detection of ectopic sources of ACTH production, especially where anatomic imaging is negative.

ACTH-Producing Thymic Carcinoid: A Rare Cause of Cushing’s Syndrome

Background: Thymic carcinoids are rare neoplasms that account for less than 5% of all thymic tumors. Approximately 25% of these tumors will result in Cushing’s syndrome due to ectopic ACTH secretion. These tumors can also be associated with MEN1 syndrome. This is a case report of a patient with history of macroprolactinoma now presenting with Cushing’s syndrome due to ectopic ACTH production from a thymic carcinoid tumor. Clinical Case: This is a 57 year old male with history of pituitary macroprolactinoma diagnosed in 2011, now status post transsphenoidal resection and external beam radiation therapy, with persistent hyperprolactinemia on cabergoline, who presented to our clinic for a routine follow up visit. Patient had already developed secondary hypogonadism and secondary hypothyroidism as a consequence of treatment for the macroprolactinoma. He complained of worsening fatigue and weight gain ongoing for several months. Laboratory studies revealed an hemoglobin A1c of 8.3% (nl < 5.7%), TSH 0.24 MIU/L (0.4-4.5 MIU/L), free T4 1.2 ng/dL (0.8-1.8 ng/dL), 8 AM cortisol 31.4 mcg/dL (4-22 mcg/dL), ACTH 185 pg/mL (6-50 pg/dL), prolactin 29.6 ng/mL (2-18 ng/mL), IGF-1 88 ng/mL (50-317 ng/mL). Follow up labs confirmed cushings syndrome: cortisol AM-DST 36.4 mcg/dL (< 2 mcg/dL), free urinary cortisol 291.9 mcg/24h (2-50 mcg/24h). Pituitary MRI showed empty sella turcica. Cortisol after an 8 mg DST 32.5 mcg/dL (< 5 mcg/dL). CT chest, abdomen and pelvis revealed an heterogeneously enhancing solid anterior mediastinal mass measuring 4.9 x 3.1 x 4.3 cm. Whole body OctreoScan showed a markedly hyperintense large mass adjacent to the right heart border measuring 47 x 32 mm. He was referred to cardiothoracic surgery and underwent a right video-assisted thoracic surgery with resection of the anterior mediastinal mass. Pathology revealed a thymic well-differentiated neuroendocrine tumor with strong cytoplasmic staining for ACTH. It was also positive for OSCAR, Cam5.2, synaptophysin, CD56, and S100. Ki67 stain was positive in fewer than 1% of tumor cells. Final diagnosis was carcinoid tumor. Conclusion: Cushing’s syndrome secondary to ectopic ACTH secretion from a thymic carcinoid is rare. The presence of two MEN1-associated tumors in this patient, macroprolactinoma and thymic carcinoid, is highly suggestive of a clinical diagnosis of MEN 1.