PMC3325752_01
Radiographic images of a radiation-induced sarcoma. A) Sagittal T1 demonstrates a heterogeneous sella mass extending from the sphenoid sinus (white arrowhead) into the hypothalamus and suprasellar cistern (white arrow); B) axial FSE T2 demonstrates the sphenoid component to be heterogenously hypointense (white arrowhead) extending into the cavernous sinus encasing the carotid (white arrow). The intracranial component is extraaxial and hyperintense with a rim of hypointensity (black arrowhead). Associated vasogenic edema in the underlying temporal lobe (black arrow). C) Axial T1 with gadolinium demonstrates solid enhancement (white arrowhead) in the extracranial portion with thick rim enhancement intracranially (black arrow); D) axial DWI (B1500) and E) ADC map both demonstrate restricted diffusion within the peripherally enhancing component; F) axial computed tomography bone window demonstrates bony erosion through the sphenoid (white arrow)
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F1
This demonstrated a destructive soft tissue mass extending from the sella into the suprasellar cistern (Figure 1A), extending medially from the sphenoid sinus through the cavernous sinus into the medial anterior cranial fossa with associated bony erosion (Figure 1F) and vasogenic edema in the underlying temporal lobe (Figure 1B). Initial MRI was done without contrast, due to patients inability to continue, with the imaging appearance concerning for a skull base neoplasm which was thought to possibly be secondarily infected due to the central region of restricted diffusion adjacent to the temporal lobe (Figure 1D,E). Follow up gadolinium-enhanced images (Figure 1C) showed the lesion to have solid heterogenous enhancement in the sphenoid sinus but thick peripheral enhancement in the region of restricted diffusion in the middle cranial fossa.
Histopathology of resected tumor demonstrates a high grade sarcoma. A) The tumor is a highly cellular, spindle cell sarcoma (hematoxylin and eosin magnification x200) and is highly mitotically active (B, hematoxylin and eosin, magnification x400). The tumor cells stain with antibodies to CD34 (C, magnification x400), and show a peri-cellular reticulin staining pattern (D, magnification x400). Immunostains for S100 protein and desmin were negative (not shown).
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F2
Reticulin stained positive (Figure 2A,D).