Frontal lobe intracerebral schwannoma mimicking metastatic lesion in a patient with papillary thyroid carcinoma.

Intracerebral schwannomas are quite rare. Due to their rarity and lack of pathognomonic imaging features, intracerebral schwannoma may be overlooked in the initial differential diagnosis of an intra-axial mass with heterogeneous ring enhancement, such as a high-grade glioma, metastasis or lymphoma. Here, we present a 21-year-old woman with prior diagnosis of papillary thyroid carcinoma and recent history of seizures who had a heterogeneously ring-enhancing left frontal lobe mass. Our presumptive diagnosis was a metastatic tumor since she had a history of thyroid cancer. Because of uncertainty in pre-operative differential diagnosis, the decision was made to proceed with excisional biopsy of the tumor via craniotomy. She underwent uneventful gross total resection of the tumor that histopathology revealed as an intracerebral schwannoma.