QuestionSBA
QuestionChoice
This would be useful in treating Addison's disease, which can cause hypotension and dizziness, but not the diarrhoea or murmur. There are no other autoimmune features or skin pigmentation mentioned which would make this diagnosis more likely.
10015797
b
Hydrocortisone and fludrocortisone
QuestionChoice
This presentation is consistent with carcinoid syndrome, due to serotonin production from a tumour. The symptoms of carcinoid syndrome include diarrhoea, flushing, hypotension, and predominantly right sided heart murmurs, which are consistent with the symptoms described in the scenario.
10015796
a
Octreotide
QuestionChoice
This presentation is not consistent with coeliac disease.
10015799
d
Gluten free diet
QuestionChoice
A low FODMAP diet may be used to treat irritable bowel syndrome, which would not explain any of the symptoms apart from diarrhoea and is a diagnosis of exclusion. There is no mention of bloating, abdominal pain or cramping, core features of IBS.
10015800
e
Low FODMAP diet
QuestionChoice
Infective endocarditis is not an unreasonable differential, however the lack of a fever or risk factors for bacterial endocarditis make this less likely.
10015798
c
Broad-spectrum antibiotics
QuestionComment
is the murmur bc carcinoid tumours cause pulmonary htn therefore tricuspid regurg?
42406
QuestionComment
from what i believe its that the hepatic metastases may result in direct exposure of the heart to serotonin, which induces plaque-like deformities on the tricuspid valve, and in turn induces valve regurgitation
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User
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Wolf
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Aaron
QuestionComment
such high yield!
45053
User
subscriber
Gastro Complement
Concept
Chapter
# Summary

Carcinoid tumours are rare, slow-growing neural crest tumours that secrete serotonin. They originate from neuroendocrine tissue commonly in the appendix and small intestine. Key symptoms may include abdominal pain, diarrhoea, flushing, wheezing, and pulmonary stenosis. Diagnosis typically involves assessment of hormone levels, imaging studies, and tissue biopsy. Management strategies primarily include pharmacological therapy, such as Octreotide to inhibit tumour products, and surgical resection when feasible.

# Definition

Carcinoid tumours are a type of neuroendocrine tumour that are typically slow-growing and can potentially become malignant. They often originate in the appendix and small intestine, with approximately 5-10% of these tumours secreting hormones, notably serotonin.

This is different to **carcinoid syndrome,** which is when the presence of liver metastases impair hepatic excretion of serotonin during first pass metabolism resulting in increased serotonergic symptoms.

# Epidemiology

Carcinoid tumours are relatively rare. They account for less than 1% of all malignancies. The incidence is approximately 1-2 cases per 100,000 people per year.

# Aetiology

Carcinoid tumours are tumours of neuroendocrine cells, which are distributed throughout the body and are concentrated in areas such as the gastrointestinal tract and lungs.

# Signs and Symptoms

Patients with carcinoid tumours may present with:

- Abdominal pain
- Diarrhoea
- Flushing
- Wheezing
- Pulmonary stenosis

These symptoms are primarily due to the effects of serotonin and its breakdown products on the systemic circulation. Patients with gastrointestinal carcinoid tumours usually only experience these symptoms if they have liver metastases, which allow tumour products to enter the systemic circulation without first undergoing metabolism in the liver.

# Differential Diagnosis

The main differential diagnoses include:

- Irritable Bowel Syndrome (IBS): Characterised by abdominal pain, bloating, and altered bowel habits.
- Inflammatory Bowel Disease (IBD): Manifests with abdominal pain, diarrhoea, and possible systemic symptoms such as weight loss and fatigue.
- Mastocytosis: This condition can cause flushing, abdominal pain, diarrhoea, and wheezing, similar to carcinoid syndrome.

# Investigations

Key investigations for carcinoid tumours include:

- Hormone level assessment: Measuring the level of 5-HIAA (5-hydroxyindoleacetic acid), a breakdown product of serotonin, in the urine can help identify carcinoid tumours.
- Imaging: CT, MRI, or Octreotide scans can help identify the location and extent of the tumour.
- Tissue biopsy: A definitive diagnosis is made through histopathological examination of biopsy material.

# Management

Treatment for carcinoid tumours can involve:

- Pharmacological treatment: Octreotide, a somatostatin analogue, is often used to inhibit the production of hormones by the tumour.
- Surgery: Resection of the tumour can be considered to alleviate symptoms and prevent further growth or metastasis.
- Other treatments such as embolisation, radiofrequency ablation, or chemotherapy may be considered based on the individual patient's clinical condition and extent of disease.

# References

[NHS conditions - Carcinoid syndrome](https://www.nhs.uk/conditions/carcinoid-syndrome/)
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Carcinoid tumours
Topic
23
Gastroenterology
15703
In gastroenterology, carcinoid syndrome is characterised by diarrhoea, flushing, hypotension, and right-sided heart valvular damage, which can be treated with octreotide to alleviate symptoms.
Presentation
202
Diarrhoea
UkmlaTopic
11
Gastrointestinal including liver
A 40-year-old man has had diarrhoea and widespread flushing for the last month. He gets dizzy when he stands up and his blood pressure is measured at 100/60mmHg. A pansystolic murmur is heard loudest over the fourth intercostal space.

Which of the following is most likely to alleviate his symptoms?
a