Fat-poor renal angiomyolipoma with prominent cystic degeneration: A case report and review of the literature

Figure 1 Computed tomography of the kidney with cystic degeneration. A: Plain computed tomography (CT) revealed an 8.6 cm × 7.4 cm, oval to round, mixed hypodense and isodense, cystic exophytic lesion with mainly liquid density; B: A smooth linear septum was observed (arrow); C: Enhanced scan revealed enhancement of the nodules and irregular wall; D: The smooth linear septum (arrow).

Figure 2 Histopathological findings of renal angiomyolipoma with cystic degeneration. A: Hematoxylin and eosin staining showed tortuous and ectatic tumor vessels with uneven and thick wall in the critical renal parenchyma; B: Randomly arranged smooth muscle-like spindle cells with nuclei of different sizes. Original magnification × 200 and × 400 (insets).

Figure 3 Immunoprofile of renal angiomyolipoma with cystic degeneration. A-F: Tumor cells exhibited positivity for neuron-specific enolase (A), human melanoma black-45 (B), Melan-A (C), S-100 (D), smooth muscle actin (E), and calponin (F); G-J: They did not express estrogen receptor (G), progesterone receptor (H), CD68 (I), or cytokeratin (J); K: The Ki-67 labeling index was less than 5%. Original magnification × 200.