Mastering Medical
USMLE Step 1 · Endocrine

Pheochromocytoma vs Neuroblastoma

How to tell Pheochromocytoma and Neuroblastoma apart when a board question makes them look alike.

Fastest separator

Pheochromocytoma is adult episodic catecholamine hypertension; neuroblastoma is a child with malignant abdominal/sympathetic tumor and VMA/HVA.

Side by side

PheochromocytomaNeuroblastoma
Key clue

Usually adult adrenal medulla catecholamine tumor with episodic headache, sweating, palpitations, paroxysmal hypertension, and elevated metanephrines.

Childhood malignant sympathetic nervous system tumor with abdominal mass, hypertension, bone pain, periorbital ecchymoses, opsoclonus-myoclonus, and elevated catecholamine metabolites.

Mechanism

Chromaffin cell tumor secretes catecholamines, often epinephrine and norepinephrine when adrenal medullary.

Malignant neural crest-derived neuroblasts arise in adrenal medulla or sympathetic chain and can produce catecholamine metabolites.

Labs and tests

Elevated plasma free metanephrines or urinary fractionated metanephrines support pheochromocytoma.

Elevated urinary VMA or HVA, Homer-Wright rosettes, and MYCN amplification support neuroblastoma.

The trap

Both can arise near the adrenal medulla and make catecholamine metabolites, so age and tumor behavior are decisive.

The repair move

For catecholamine tumors, first ask adult episodic endocrine tumor versus pediatric malignant neural crest tumor.

Try a free question

Core

An adult has recurrent severe headaches, sweating, palpitations, paroxysmal hypertension, and elevated plasma free metanephrines. Which diagnosis is most likely?

Show answer and explanation

Answer: A. Pheochromocytoma. Adult episodic catecholamine symptoms with elevated metanephrines point to pheochromocytoma.

Why the other choices are tempting

  • B. Neuroblastoma is a malignant pediatric sympathetic tumor with abdominal mass and VMA/HVA clues.
  • C. Carcinoid syndrome causes flushing, diarrhea, bronchospasm, and 5-HIAA elevation.
  • D. Conn syndrome causes aldosterone-driven hypertension with hypokalemic metabolic alkalosis.
  • E. Thyroid storm causes decompensated thyrotoxicosis with abnormal thyroid labs.

Flashcards

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What symptom triad points to pheochromocytoma?

Episodic headache, sweating, and palpitations with hypertension point to pheochromocytoma.

What age pattern points to neuroblastoma?

A young child with abdominal mass and sympathetic tumor clues points to neuroblastoma.

Quick answers

What is the fastest way to tell Pheochromocytoma from Neuroblastoma?

Pheochromocytoma is adult episodic catecholamine hypertension; neuroblastoma is a child with malignant abdominal/sympathetic tumor and VMA/HVA.

What is the key clue for Pheochromocytoma?

Usually adult adrenal medulla catecholamine tumor with episodic headache, sweating, palpitations, paroxysmal hypertension, and elevated metanephrines.

What is the key clue for Neuroblastoma?

Childhood malignant sympathetic nervous system tumor with abdominal mass, hypertension, bone pain, periorbital ecchymoses, opsoclonus-myoclonus, and elevated catecholamine metabolites.

What is the common trap with Pheochromocytoma vs Neuroblastoma?

Both can arise near the adrenal medulla and make catecholamine metabolites, so age and tumor behavior are decisive.