Axial chordoma and parachordoma (soft tissue chordoma): two of a kind: report of two cases with primary diagnosis on fine-needle cytology samples.

This report concerns one case of sacrococcygeal chordoma and one case of parachordoma (soft-tissue chordoma) that were primarily diagnosed on fine-needle cytology (FNC) samples. Both neoplasms consisted of medium-sized epithelioid cells with eccentric, nucleolated nuclei, displaying abundant cytoplasm filled with bubbly vacuoles with refractile borders (physaliphorous cells). The neoplastic cells were embedded in an abundant extracellular substance staining metachromatically with Diff-Quik™. Both neoplasms had a typical clinical and instrumental presentation (primary sacrococcygeal tumor in a 58-year-old man and primary soft tissue mass of the hand palm and wrist in a 31-year-old man). The cytopathological findings in both the neoplasms were so similar as to be almost indistinguishable, and this similarity included the immunocytochemical findings. The deep similarity between these neoplasms indicates that the only pathological differences in the described cases probably reside in their different anatomical location and, perhaps, in different cytogenetic changes.