PMC3114311_01
PMC3114311_02
T1-weighted MRI scans with contrasts showing (a) axial, (b) coronal, and (c) sagittal images of the lesion
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F1
Of concern was adjacent meningeal enhancement, but there was no abnormal signal identified within the brain parenchyma itself [Figure 1].
PMC3114311_03
Immunohistochemical stains of the biopsied tissue. (a) CD68, (b) S100+, and (c) CD1a+ stains (original magnification, x100)
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F2
For the first case, the intraoperative cultures were negative and the pathological study demonstrated a lesion with histiocytic and eosinophilic infiltrate, which stained positive for CD1a (+) and S100 (+) [Figure 2].
Electron micrograph of the biopsied tissue. Electron micrograph was of compromised quality as the thin sections were recovered from fixed paraffin embedded tissue. Membrane bound electron lucent vesicles suggestive of a component of Birbeck granules are seen within the histiocytes. The typical cross-striated rod domain is not as evident
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F3
EM studies revealed atypical inclusion bodies consistent with pathognomonic Birbeck granules [Figure 3].