A rare benign parenchymal renal hamartoma.
Found in 1-3% of the general population, and accounts for 0.5% of all renal tumors.
Often associated with tuberous sclerosis complex and may be associated with seizures, adenoma sebaceum in 20-50%, and mental retardation, retinal phacoma, and brain and visceral hamartomas.
May be associated with flank pain, palpable tender mass, discomfort, fever, and gross hematuria.
Associated with hemorrhage in 15% of patients and in patients with tumors larger than 4 cm up to 50-60% have bleeding.
Second most common real cause of retroperitoneal hemorrhage, following renal adenocarcinoma.
May be associated with nausea, vomiting, hypertension, leukocytosis, real insufficiency, and anemia.
Histologic findings show a proliferation of spindle cells, epithelial cells and adipocytes with many thick-walled blood vessels.
Diagnosis can be established on CT scans or MRI examinations without biopsy.
Imaging studies demonstrate high fat content of the lesions.
Management includes transcatheter selective arterial embolization.
Prophylactic embolization of large lesions may be done in select patients.
Renal sparing surgery with partial nephrectomy is reserved for patients who have continuing hemorrhage or suspected malignancy and in whom embolization fails.