QuestionSBA
QuestionChoice
Noradrenaline is the primary neurotransmitter of the sympathetic nerves in the cardiovascular system. High levels of noradrenaline may cause anxiety, hypertension, tachycardia, disturbed sleep, hyperglycaemia, and headaches. It would not be raised due to a carcinoid tumour.
10006854
d
Noradrenaline
QuestionChoice
ACTH is not produced by a carcinoid tumour and excess levels would not result in the symptoms described above. ACTH is produced by the pituitary gland and stimulates the release of cortisol from the adrenal glands. ACTH may be raised in Cushing's disease, Addison's disease, multiple endocrine neoplasia, or ectopic ACTH-secreting tumours (e.g. small cell lung cancers).
10006853
c
Adrenocorticotrophic hormone (ACTH)
QuestionChoice
TSH is produced by the anterior pituitary gland and stimulates thyroid hormone production by the thyroid gland. It is typically raised in hypothyroidism, accompanied by symptoms of weight gain, depression, constipation, and fatigue among others.
10006855
e
Thyroid-stimulating hormone (TSH)
QuestionChoice
This patient has a carcinoid tumour, which is a slow-growing malignant tumour which develops within the neuroendocrine system. A small portion of these tumours secrete hormones, most commonly serotonin. Excess serotonin secretion results in the symptoms of abdominal pain, diarrhoea, flushing and wheeze often seen in these patients. Diarrhoea is a common presenting symptom and may present on its own, so is often misdiagnosed as IBS.
10006851
a
Serotonin
QuestionChoice
Octreotide - a radiolabelled somatostatin analogue - is often used to investigate for and treat carcinoid tumours, as it inhibits the release of tumour products, but would not cause the symptoms of this patient as it is not released by the tumour. Somatostatin produces neuroendocrine inhibitory effects, regulates the activity of the gastrointestinal tract, and prevents rapid cell proliferation.
10006852
b
Somatostatin
Concept
Chapter
2693
4547
Carcinoid tumours
Topic
221
Endocrine
13917
A 54-year-old man presents to his GP complaining of diarrhoea, facial flushing, and abdominal pain. Examination reveals a slight wheeze bilaterally. He has a two-year history of irritable bowel syndrome (IBS). A colonoscopy is performed which identifies a polyp. A biopsy confirms a carcinoid neuroendocrine tumour.

Which of the following hormones is responsible for the patient's symptoms?
a