Cytomorphology of Recurrent Osseous Extracranial Meningioma of Right Pubic Ramus:: Report of a Case and Literature Review.

Meningiomas are well-recognized neoplasms of the central nervous system. Primary extracranial meningiomas (ECMs) are extremely rare and arise in various anatomic sites. We present a 56-year-old female with 13-year history of primary grade I meningothelial meningioma of right pubic symphysis, orthotopic heart transplant, and right total hip arthroplasty, who presented with progressive right hip pain for 3 weeks. Primary intracranial, intraspinal and other tumors were excluded. Imaging revealed a destructive lytic lesion at right superior and inferior pubic rami and body, associated with extensive bone destruction and soft tissue mass. Touch imprint (TI) cytology of computed tomography (CT)-guided core biopsy from the right pubic ramus (PRA) lesion showed a spindle cell neoplasm, with classical syncytial, lobular, and whorling cellular arrangement, composed of spindle, oval or round nuclei with occasional pseudoinclusions, consistent with known history of osseous meningioma. Tumor was further characterized by histopathology as grade 1 meningioma with meningothelial features. To our knowledge, primary osseous ECM arising specifically at the PRA has not been reported previously. ECM at this site may pose a diagnostic challenge for cytologists as its features may resemble other more commonly observed lesions. Accurate diagnosis requires awareness of occurrence of ECM at PRA and recognition of its characteristic cytomorphology. TI cytological features of our case are presented and previously described cytology of ECMs and diagnostic pitfalls are reviewed. Diagn. Cytopathol. 2016;44:618-622. © 2016 Wiley Periodicals, Inc.