Frozen Section Can "Sharpen" or "Sand Off" the Surgeon's Knife: 2 Case Illustrations with Skull Base Meningioma Mimics.

Abstract

Lesions at the skull base warrant careful evaluation of imaging and meticulous preoperative planning. Unnecessary radical resection of these lesions could add to surgical morbidity. Occasionally, dural-based inflammatory or infectious lesions at this site radiologically mimic meningiomas, which are commonly encountered entities at this site. Not all lesions require excision, and it could be harmful in a few cases. Two patients had skull base lesions that resembled a meningioma on imaging, whereas frozen section in both cases differed from the preoperative diagnosis, showing an inflammatory lesion in the first case and invasive aspergillosis in the second case. Formalin-fixed, paraffin-embedded sections confirmed the frozen section diagnosis. Safe resection was performed in the first case, whereas surgery was abandoned and the patient was started on antifungal therapy in the second case. Both patients had a good outcome. This report underscores the usefulness of intraoperative frozen section to decide on a further course of treatment when faced with such unexpected situations. Frozen sections and crush smears hold great potential to avoid unwarranted surgical morbidity, particularly for skull base lesions.