A 17-year-old girl with seizures and facial angiofibromas undergoes CT abdomen, which shows bilateral renal lesions containing fat density. Which histologic composition confirms the diagnosis?
- A Sheets of uniform round cells with abundant eosinophilic granular cytoplasm and a central stellate scar
- B Papillary fronds lined by cells with scanty pale cytoplasm and psammoma bodies
- C Disorganized mixture of thick-walled dysmorphic blood vessels, smooth muscle, and mature adipose tissue ✓
- D Solid nests of clear cells with a delicate branching vascular network
Correct answer: C. Disorganized mixture of thick-walled dysmorphic blood vessels, smooth muscle, and mature adipose tissue
Explanation
Angiomyolipomas are hamartomatous tumors composed of dysmorphic vessels, smooth muscle, and adipose tissue, occurring in up to half of patients with tuberous sclerosis, whose cutaneous signs include angiofibromas and hypopigmented macules. Fat density on imaging distinguishes them from renal cell carcinoma. Uniform granular cells with a central scar describe oncocytoma, and clear cell nests describe conventional renal cell carcinoma.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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