PMC6417335_01
Case 1 (a) Axial T1-weighted, (b) Axial T2-weighted, and (c) coronal fluid-attenuated inversion recovery reveal a well-demarcated lobulated mass in the right temporal region causing bone erosion. It has an intracranial component and is hypointense on T1 and heterogeneously hyperintense on T2 and fluid-attenuated inversion recovery images
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F1
T2-weighted and fluid-attenuated inversion recovery images [Figure 1]. The patient underwent right temporal craniotomy and stereotactic gross total excision of the lesion. The postoperative period was uneventful.
Photomicrograph of Case 1 shows the following: (a) tumor composed of relatively uniform short spindly cells embedded in hyalinized stroma with foci of "grungy" calcification (H and E, x400); (b-d) tumor cells are diffusely positive for vimentin (x400), focally positive for smooth muscle actin (x400), and negative for CD34 (x200)
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F2
Histopathology revealed a cellular tumor composed of sheets of oval-to-short fusiform cells possessing scanty cytoplasm and relatively uniform-appearing nuclei [Figure 2a]. Foci of "grungy" calcification were also detected [Figure 2a]. On immunohistochemistry, the tumor cells were diffusely positive for vimentin and focally positive for smooth muscle actin, whereas they were negative for S100 and CD34 [Figure 2b-d].
PMC6417335_02
Photomicrograph of Case 2 shows the following: (a) numerous osteoclastic giant cells and a richly vascularized stroma (H and E, x400); (b) extracellular basophilic matrix (H and E, x400)
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F3
Histopathology revealed fragments of neoplasm composed of oval-to-short fusiform cells arranged in sheets and fascicles within a vascularized stroma, containing thin-walled vessels and numerous scattered osteoclastic giant cells [Figure 3a]. Areas showing basophilic extracellular matrix were also identified [Figure 3b].