Pheochromocytoma is a rare neuroendocrine tumor arising from chromaffin cells, typically found in the adrenal medulla but may also occur in extra-adrenal locations, known as paragangliomas. These tumors produce and release excessive amounts of catecholamines, including adrenaline and noradrenaline, leading to episodic or sustained hypertension and a variety of systemic symptoms.

Etiology:

• Most pheochromocytomas are sporadic, but about 25-30% are associated with hereditary syndromes such as multiple endocrine neoplasia type 2 (MEN 2), von Hippel-Lindau (VHL) syndrome, neurofibromatosis type 1 (NF1), and familial paraganglioma-pheochromocytoma syndromes.
• Mutations in various genes such as RET, VHL, NF1, SDHx, and others are implicated in the pathogenesis of hereditary forms.

Clinical Presentation (The 5 P’s):

• Pressure (Hypertension): Episodes of severe, paroxysmal hypertension are characteristic, often exceeding 200/100 mmHg.
• Pain (Headaches): Severe headaches are common, often described as pounding or throbbing.
• Perspiration (Diaphoresis): Profuse sweating is a frequent symptom, even during episodes of hypertension.
• Palpitations: Patients may experience palpitations or tachycardia due to excess catecholamines.
• Pallor: Pallor or a pale appearance may be observed during hypertensive episodes.

Diagnostic Workup:

• Diagnosis is confirmed through biochemical testing measuring plasma or urine levels of metanephrines or catecholamines during symptomatic episodes.
• Imaging studies, including CT, MRI, or metaiodobenzylguanidine (MIBG) scintigraphy, are used to localize the tumor and assess its extent.

Management:

• Surgical resection is the definitive treatment for pheochromocytoma.
• Preoperative management involves alpha-adrenergic blockade followed by beta-adrenergic blockade to prevent hypertensive crisis during tumor manipulation.
• Inoperable or metastatic tumors may be managed with medical therapy or radiotherapy.

Prognosis:

• Early detection and surgical intervention lead to excellent long-term outcomes.
• Approximately 10% of cases are malignant, with metastases most commonly involving the lymph nodes, liver, and bone.

“Rule of 10s” in pheochromocytoma:

• 10% Malignant
• 10% Extra-adrenal
• 10% Bilateral
• 10% Hereditary
• 10% Calcify
• 10% Occur in Children