The lack of typical cytological features challenged the diagnosis in a case of chordoma

Background : Chordomas are an uncommon malignant mesenchymal tumor that arises in the spinal axis with a predilection for the sacrum and base of the skull. We herein describe a case of chordoma, in which other tumors were pre-operatively considered due to the lack of typical cytological features associated with chordoma.Case : A 69-year-old woman presented to us with persistent pain around the sacral area. MRI revealed a lobulated mass located in the sacrum. Fine needle aspiration cytology (FNAC) biopsy found cohesive clusters of spindle or polygonal cells in a myxoid background, but the presence of physaliphorous cells was not evident. The cytological findings were highly suggestive of a malignant mesenchymal tumor such as a chondrosarcoma. On histological examination, the majority of tumor cells were a mixture of cohesive epithelioid cells with abundant eosinophilic cytoplasm and physaliphorous cells with cytoplasmic vacuoles. Immunohistochemical examination confirmed the diagnosis of chordoma by showing that the tumor cells were positive for AE1/AE3, s-100, and EMA.Conclusion : We need to be aware that chordoma can sometimes present without typical cytological findings such as physaliphorous cells, making the pre-operative diagnosis difficult.