Differentiating carcinoid syndrome from other diseases

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Parminder Dhingra, M.D. [2]

Overview

Carcinoid syndrome must be differentiated from systemic mastocytosis, medullary thyroid carcinoma, irritable bowel syndrome, malignant neoplasms of the small intestine, benign cutaneous flushing, and recurrent idiopathic anaphylaxis.

Differentiating Carcinoid Syndrome from other Diseases

Carcinoid syndrome must be differentiated from:

• Systemic mastocytosis
• Medullary thyroid carcinoma
• Irritable bowel syndrome
• Malignant neoplasms of the small intestine
• Benign cutaneous flushing
• Recurrent idiopathic anaphylaxis

On the basis [symptom 1], [symptom 2], and [symptom 3], [disease name] must be differentiated from [disease 1], [disease 2], [disease 3], [disease 4], [disease 5], and [disease 6].

Diseases		Clinical manifestations												Para-clinical findings										Gold standard	Additional findings
		Symptoms						Physical examination
														Lab Findings			Imaging						Histopathology
		Abdominal pain	Diarrhea	Flushing	Dyspnea	Palpitations	Other symptoms	Wheezing	Telangiectasia	Hypotension	Tachycardia	Systolic murmur of tricuspid regurgitation	Other physical findings	Urinary 5-hydroxyindoleacetic acid (5-HIAA)	Serum Chromogranin A (CgA)	Other markers	Abdominal computed tomography (CT)	MRI	Somatostatin receptor scintigraphy [SRS], or Octreoscan	Metaiodobenzylguanidine (MIBG) scintigraphy	Other diagnostic studies	Transthoracic echocardiography
Carcinoid Syndrome	Midgut tumours	+ Mild	+ Intermittent Secretory type	+	+	+	Pellagra Dermatitis Diarrhea Dementia	+	+	+	+			+	+	NT-proBNP Screening of carcinoid heart disease Blood Serotonin levels			+ Localization of carcinoid tumor		Positron emission tomography-computed tomography (PET-CT) using 18-fluoro-dihydroxyphenylalanine Ki-67 labeling index	Valve thickening with retraction and reduction in the mobility of the tricuspid valve		Somatostatin receptor scintigraphy [SRS], or Octreoscan	Mesenteric fibrosis Pathognomonic radiological sign of midgut NET.
	Bronchial carcinoid
Irritable Bowel Syndrome		+ Perioidic	Intermittent Chronic history of diarhea alternating with constipation				Associated with other conditions Fibromyalgia Chronic fatigue syndrome Gastroesophageal reflux disease, Functional dyspepsia Non-cardiac chest pain, Major depression ,Anxiety							-	-
Malignant neoplasms of small intestine
Crohn disease		Right lower quadrant pain	+/-	-	-	-							oral lesions Perianal lesions	-	-	CRP may be high					Endoscopy
Benign cutaneous flushing
Systemic mastocytosis		+	+	+	+	-	Maculopapular rash Pruritus	+/-	+/-	+	-	-	Diffuse musculoskeletal pain Neuropsychiatric symptoms	-	-	Activating mutations of KIT Serum Tryptase leevs			-	-
Recurrent idiopathic anaphylaxis
Asthma exacerbation		-	-	-	+	+		+	-	-	+	-		-	-						Chest X ray
Acute Urticaria
Anaphylaxis
Angioedema
Drugs causing flushing																									Nicotinic acid Levodopa Bromocriptine Diltiazem
Medullary Thyroid Carcinoma