Free sample case · CQ-2167
HardFree case
This is a real ClinQuiz case. In the app you start with 100 points, every investigation you open costs points and every wrong guess costs points too. Read the patient, open only the tests you need, then type your diagnosis. Everything below is also written out in full, so you can simply read it top to bottom.
A 59-year-old female presents with an 8-month history of sudden facial redness accompanied by a burning sensation. She reports 6 to 8 watery, non-bloody bowel movements daily that occur independent of food intake.
Choose which areas to open. In the app each one costs points to unlock, and the more you have already opened, the more the next one costs.
Patient states that she was treated with loperamide and anti-histamines without control of flushing or bowel frequency. She is post-menopausal for 7 years and tried hormone replacement therapy without effect on her red face spells. She takes no other medications.
Physical examination during an episode demonstrates intense erythema and warmth over the face, neck, and upper chest without sweating (dry flush). Abdominal examination reveals a firm, non-tender 4 cm hepatomegaly. Auscultation reveals bilateral mild expiratory wheezes.
Electrocardiogram demonstrates normal sinus rhythm with sinus tachycardia at 92 bpm during flushing episode.
Laboratory testing demonstrates markedly elevated 24-hour urinary serotonin metabolic end-product excretion and elevated serum Chromogranin A levels.
Multiphasic abdominal CT reveals a 2.2 cm hypervascular primary mass in the terminal ileum with mesenteric fibrosis/desmoplasia and multiple hypervascular liver metastases. Gallium-68 DOTATATE PET-CT shows high somatostatin receptor expression.
The answer
Carcinoid syndrome is a paraneoplastic syndrome caused by systemic release of vasoactive substances (serotonin, histamine, bradykinin, prostaglandins) from a neuroendocrine tumor, most commonly originating in the distal ileum with liver metastases.
Presents with episodic dry flushing (cutaneous vasodilation), secretory nocturnal diarrhea, abdominal cramping, bronchospasm (wheezing), and eventual carcinoid heart disease.
Circulating serotonin stimulates gastrointestinal motility and intestinal fluid secretion causing secretory diarrhea, while bradykinin and histamine cause cutaneous vasodilation (flushing) and bronchospasm.
Primary gastrointestinal NETs release serotonin into the portal vein, where it is metabolized by hepatic monoamine oxidase. When hepatic metastases develop (or extraportal drainage occurs), vasoactive humors escape hepatic clearance directly into systemic circulation.
Diagnosis is confirmed by elevated 24-hour urinary 5-hydroxyindoleacetic acid (5-HIAA) levels (end-product of serotonin metabolism), elevated serum Chromogranin A, CT/MRI localization, and 68Ga-DOTATATE PET-CT imaging.
Differential diagnoses include menopausal hot flashes, systemic mastocytosis, pheochromocytoma, medullary thyroid cancer, and irritable bowel syndrome.
Initiate long-acting somatostatin analog therapy (lanreotide or octreotide LAR) and obtain an echocardiogram.
Symptom control and disease stabilization require long-acting somatostatin analogs (octreotide LAR or lanreotide), along with telotristat ethyl (tryptophan hydroxylase inhibitor) for refractory diarrhea, surgical resection, or liver-directed therapies.
Complications include carcinoid crisis (life-threatening hypotension, arrhythmia, and bronchospasm during surgery/stress), carcinoid heart disease (right-sided valvular lesions), severe bowel obstruction due to mesenteric desmoplasia, and pellagra (niacin deficiency).
ClinQuiz has a new case every day on iPhone and Android. The free plan includes daily cases; a subscription unlocks every case and every investigation. Download ClinQuiz.
Last updated 22 October 2026. Medical education only: all cases are simulated and must not guide real patient care.
ClinQuiz