Parapharyngeal chordoma: a diagnostic challenge and potential mimic of pleomorphic adenoma on fine-needle aspiration cytology

Chordoma: analysis of 47 fine-needle aspiration biopsy, cytologic imprint, and small biopsy specimens

INTRODUCTION

Fine-needle aspiration (FNA) and small tissue biopsy of chordoma have been reported in several small series, but no large series exists. We undertook an examination of 47 cases (with concurrent core needle biopsy in a subset) to analyze diagnostic accuracy, cytomorphology, and immunohistochemistry.

MATERIALS AND METHODS

Our cytopathology files were searched for examples of chordoma with histopathologic verification. FNA biopsy smears and core needle were performed using standard techniques.

RESULTS

Forty-seven cases of chordoma were retrieved from 44 patients [M:F; 1.8:1; age range 5-81 years; mean age 55 years]. Twenty-seven presented with primary, 10 with locally recurrent, and 7 with metastatic tumors. Two aspirates were from the appendicular skeleton, 2 from the trunk, 1 from neck lymph node, and 42 aspirates (89%) from axial and peri-axial skeleton and surrounding soft tissues. Four were cytologic touch imprints while the remainder were FNA biopsy specimens. Specific cytologic diagnoses were chordoma/consistent with chordoma (44 cases, 94%), suspicious for chordoma (2), and malignant neoplasm (1). Along with a single case of benign notochordal tumor misdiagnosed as chordoma, our diagnostic accuracy was 91%. Concurrent tissue biopsy was performed in 51% of cases. Immunohistochemical staining of tumor in 29 (62%) cases showed expression of brachyury in 23 of 24 (96%) instances. Cytopathology consisted of cellular smears populated by large cells possessing enormous amounts of vacuolated and non-vacuolated cytoplasm with an abundant background myxoid/chondromyxoid stroma.

CONCLUSIONS

FNA and small tissue biopsy specimens show a very high degree of diagnostic accuracy in recognition of chordoma.

Skull base chordoma presenting as nasopharyngeal mass with lymph node metastasis

Spheno-occipital chordomas can rarely present as nasopharyngeal mass. Metastases occur only in advanced disease. They can pose a diagnostic dilemma when information about diagnosis of the primary tumor is not available. We present cytological findings in upper cervical lymph node of a case of nasopharyngeal chordoma and discuss possible differential in such a location.