Ectopic ACTH syndrome in a dog with a mesenteric neuroendocrine tumour: a case report

Abstract

Ectopic ACTH secretion is provoked by extra-pituitary tumours that secrete ACTH, constituting an infrequent type of Cushing Syndrome in the dog. Neuroendocrine tumours (NET) are characterised by the synthesis of peptides with hormone activity. A dog with clinical diagnosis of Cushing's syndrome and presenting an abdominal tumour located in the area of the left adrenal gland was sent to the hospital. Cortisol was not inhibited at four and eight hours after the application of low-dose dexamethasone and the cortisol/creatinine ratio was elevated (93 × 10 -6 , reference values < 10 × 10 -6 ). Plasma ACTH measurements were high (28.6 pmol/l, reference values 5.5-14.3 pmol/l). On computed tomography, the tumour was found in the meso-epigastrium, with both adrenal glands hyperplasic and no alteration of the pituitary image. The tumour was located between the two layers of the meso-colon and was removed using laparoscopy. After surgery, ACTH concentrations became normal and clinical signs remitted. The histopathological diagnosis was NET, with positive ACTH immunostaining.

Ectopic Cushing’s syndrome associated with a pheochromocytoma in a dog: a case report

“…Ectopic Cushing's syndrome accounts for approximately 5% of all human cases of Cushing's syndrome [3]. Primary hepatic carcinoid and neuroendocrine tumors are reportedly related to ECS; however, to the authors' knowledge, canine ECS related to pheochromocytoma has not been previously reported [4][5][6]. In the present case study, we describe ECS caused by pheochromocytoma in a dog.…”

“…Ectopic production of CRH and ACTH has been reported infrequently in humans and rarely in dogs. To the authors' knowledge, ECS caused by pheochromocytoma in dogs has not been previously reported, although previous case reports involving canines with mesenteric neuroendocrine tumors and a primary hepatic carcinoid suggested that the tumors were related to ECS [4][5][6]. A case involving a 5-year-old male Dachshund with Cushing's syndrome was reportedly due to ectopic secretion of ACTH by an unidentified microadenoma.…”

“…To further investigate the association of the pheochromocytoma with hypercortisolism, we performed immunohistochemistry for ACTH, which showed negative findings for the neoplastic cells. In previous reports of a pituitary ganglioma and mesenteric neuroendocrine tumor, the presence of ectopic ACTH syndrome was confirmed by positive immunohistochemistry for adrenocorticotropin in the surgically resected tumors [6,25]. In contrast, some studies have reported cases of ectopic ACTH syndrome, although they did not show positive immunostaining for ACTH in the neoplastic tissue [4,5,26,27].…”

Canine adrenocorticotropic hormone-producing sinusoidal neuroendocrine tumor associated with Cushing’s disease

“…NETs are rarely functional in animals to secrete hormones, including glucagon and serotonin, leading to hormone-associated diseases [1,3,17,20]. As far as we known, adrenocorticotropic hormone (ACTH)-producing NET has been only reported in one dog [3]. The present report describes the computed tomographical, histopathological, and immunohistochemical findings of ACTH-producing NET found in the sinusoidal cavity and brain in an 18-year-old dog in association with Cushing's disease.…”

“…As the clinical, histopathological, and immunohistological characteristics of these tumors, particularly in the nasal cavities and brain, are similar to other tumors, such as olfactory neuroblastomas, differential diagnosis is usually required [24]. NETs are rarely functional in animals to secrete hormones, including glucagon and serotonin, leading to hormone-associated diseases [1,3,17,20]. As far as we known, adrenocorticotropic hormone (ACTH)-producing NET has been only reported in one dog [3].…”