The core biopsy confirmed the diagnosis.

Histology

MICROSCOPIC DESCRIPTION: Sections show a spindle cell tumor composed of poorly formed intersecting fascicles. There are focal pallisaded tumor nuclei, consistent with Verocay body formation. There is mild nuclear atypia with nuclear elongation and hyperchromasia. There are scattered lymphocytes, together with foamy and hemosiderin laden macrophages. No mitoses or necrosis are seen. There is no evidence of malignancy. Immunohistochemical results show tumor cells stain: S100+, SOX10+, CKAE1/3- and EMA-.

FINAL DIAGNOSIS: Schwannoma.