The cytological features of low-grade fibromyxoid sarcoma as a hybrid tumor with sclerosing epithelioid fibrosarcoma

Abstract

Background : We encountered a case of low-grade fibromyxoid sarcoma (LGFMS) as a hybrid tumor with sclerosing epithelioid fibrosarcoma (SEF).

Case : A man in his 50 s presented to us with an axillary mass, which was removed by operation. The cytological features were as follows : atypical cells with spindle- or oval-shaped nuclei were found in a myxoid background that showed metachromasia on Giemsa staining. The cellularity of the clusters was not very high, and mitotic figures were unclear. We suspected that the mass was a benign, or at most low-grade malignant, mesenchymal tumor, but were unable to list possible histological types in the differential diagnosis. Finally, on histopathology, the tumor showed two histological types, both of which showed positive immunohistochemical staining for MUC4. The cytological features that we observed in this case were consistent with the diagnosis of LGFMS.

Conclusion : The histological features were reflected in the cytological findings of this case. Giemsa staining was helpful for the diagnosis of this condition. Thus, Giemsa staining, in addition to Papanicolaou staining, is useful for delineating the cytological features of soft tissue tumors.