Adrenal myelolipoma

Overview
Adrenal myelolipoma is a rare benign neoplasm. It is made up of mature adipose tissue and a variable amount of hematopoietic elements. Most lesions are small and asymptomatic. They are usually discovered incidentally at autopsy or on imaging studies performed for other reasons. Most tumors are unilateral but show no predilection to one particular side. Tumor size varies from several millimeters to more than 30 cm.

Epidemiology and Demographics
The incidence varies from 0.08-0.4% at autopsy.

Pathophysiology & Etiology
A myelolipoma may represent a site of extramedullary hematopoiesis. The most widely accepted theory is the existence of metaplasia of the reticuloendothelial cells of blood capillaries in the adrenal gland in response to stimuli such as necrosis, infection, or stress.