Carcinoid syndrome revealed by chronic diarrhea and isolated severe tricuspid regurgitation.
Chronic diarrhea and isolated right-sided valvulopathy should prompt evaluation for carcinoid syndrome, even if electrolyte derangement is the dominant feature.
Where it sits
this study against the rest of the octreotide corpusSummary and findings
A woman in her 50s with hypertension and severe hyponatremia presented with chronic diarrhea and tricuspid regurgitation. CT revealed a calcified mesenteric mass and hepatic lesions, and laboratory tests confirmed carcinoid syndrome. Discontinuation of hydrochlorothiazide and treatment with isotonic saline, octreotide, and furosemide improved her symptoms.
Abstract
Carcinoid syndrome is an uncommon manifestation of metastatic neuroendocrine tumor (NET) and may present without classic flushing or bronchospasm. We describe a woman in her 50s with hypertension treated with hydrochlorothiazide who presented with confusion, severe hyponatremia with a serum sodium concentration of 114 mmol/L (reference range, 135-145 mmol/L), chronic watery diarrhea, bilateral leg edema, and 40-lb weight loss. Computed tomography (CT) revealed a calcified mesenteric mass and multiple hepatic lesions. Serum chromogranin A was 1434 ng/mL (SI: 1434 µg/L) (reference range, <100 ng/mL [SI: <100 µg/L]), and 24-hour urinary 5-hydroxyindoleacetic acid (5-HIAA) was 108 mg/24 hours (SI: 565 µmol/24 hours) (reference range, <6 mg/24 hours [SI: <31 µmol/24 hours])-well above the threshold associated with carcinoid heart disease (CHD). Transthoracic echocardiography demonstrated severe tricuspid regurgitation with retracted leaflets, consistent with CHD. Liver biopsy confirmed a well-differentiated grade 2 NET. Urine sodium <20 mmol/L and urine osmolality 188 mOsm/kg indicated volume depletion from gastrointestinal losses, aggravated by hydrochlorothiazide. Hydrochlorothiazide was discontinued; isotonic saline, octreotide, and furosemide improved hyponatremia, diarrhea, and edema. Chronic diarrhea with isolated right-sided valvulopathy should prompt evaluation for carcinoid syndrome even when electrolyte derangement dominates.
Background
Carcinoid syndrome is a rare manifestation of metastatic neuroendocrine tumors (NETs), often presenting with symptoms like flushing and bronchospasm. However, it can also present atypically, as in this case, with chronic diarrhea and isolated tricuspid regurgitation. Understanding such atypical presentations is crucial for timely diagnosis and management.
Methods
This case report describes a single patient, a woman in her 50s, presenting with chronic diarrhea, severe hyponatremia, and tricuspid regurgitation. Diagnostic imaging and laboratory tests were used to identify a calcified mesenteric mass, hepatic lesions, and elevated biomarkers indicative of carcinoid syndrome. Treatment involved discontinuing hydrochlorothiazide and administering isotonic saline, octreotide, and furosemide.
Results
The patient had a serum sodium concentration of 114 mmol/L, serum chromogranin A of 1434 ng/mL, and 24-hour urinary 5-HIAA of 108 mg/24 hours. Echocardiography showed severe tricuspid regurgitation. Discontinuation of hydrochlorothiazide and treatment with isotonic saline, octreotide, and furosemide improved her hyponatremia, diarrhea, and edema.
Interpretation
This case highlights the importance of considering carcinoid syndrome in patients with chronic diarrhea and right-sided valvulopathy, even when classic symptoms are absent. The improvement of symptoms with octreotide suggests its potential utility in managing such cases, although this is based on a single patient and may not be generalizable.
Key findings
- Serum sodium concentration of 114 mmol/L (reference range, 135-145 mmol/L).
- Serum chromogranin A was 1434 ng/mL (reference range, <100 ng/mL).
- 24-hour urinary 5-HIAA was 108 mg/24 hours (reference range, <6 mg/24 hours).
- Severe tricuspid regurgitation with retracted leaflets observed.
- Liver biopsy confirmed a well-differentiated grade 2 NET.
Limitations
- Single case report
- Findings specific to one patient
- Limited generalizability
- No control group
- Short follow-up