PMC4578063_01
The CT scan of the thorax at aortic arch level showed a 4x3x3 cm-sized, well-defined mass in the posterior mediastinum. The mass showed high density with good contrast enhancement (arrow).
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The computed tomographic (CT) scan of the thorax, obtained after the injection of contrast material, showed a 4x3x3cm-sized, well-defined high density posterior mediastinal mass with a suspicious finding of rib destruction (Figure 1).
MRI imaging of the thoracic spine revealed an ovoid mass in the posterior mediastinum at T4-5 level with low signal intensity in T1-weighted image which is well enhanced after injection of contrast media. Epidural space invasion by the tumor was suspected (arrow).
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MRI imaging of the thoracic spine revealed a round mass in the posterior mediastinum at T4-5 level with low-signal intensity in T1-weighted image which was well enhanced and with suspicious epidural space-nvasion (Figure 2).
Histologic section of the tumor revealed exuberant mesenchymal proliferation which was intricately composed of mature adipocytes, opened or closed capillaries and smooth muscle fibers (H & E, x100).
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Histologically, the tissue was characterized by mesenchymal cell proliferation, intricately composed of mature fat, capillaries and smooth muscle fibers (Figure 3).
(A) The smooth muscle component showed scattered bundles of slender spindle cells with eosinophilic fibrillary cytoplasms and cigar-shaped nuclei (H & E, x200). (B) The smooth muscle fibers were immunohistochemically positive for smooth muscle actin (Avidin-biodin peroxidase, x200).
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In immunohistochemical staining to identify the different components of angiomyolipoma, smooth muscle actin was positive for smooth muscle component (Figure 4A, 4B), CD34 (Figure 5) and factor-VIII for vascular component were positive and S-100 was positive for fat component.
Immunostaining for CD34 antigen revealed many CD34-reactive capillaries intermingled with mature adipocytes (ABC method, x100).
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In immunohistochemical staining to identify the different components of angiomyolipoma, smooth muscle actin was positive for smooth muscle component (Figure 4A, 4B), CD34 (Figure 5) and factor-VIII for vascular component were positive and S-100 was positive for fat component.