Cytomorphologic features of fine-needle aspiration of liposarcoma

The cytomorphologic features of fine-needle aspirates (FNA) of liposarcomas have not been fully characterized. In the current study, we attempted to identify cytological attributes of liposarcoma in FNA. Twelve FNAs of histologically proven liposarcomas were used for this study. They included 10 myxoid and two well-differentiated liposarcomas. Four cytological criteria were chosen for evaluation. These included a complex capillary network, increased cellularity, the presence of a metachromatic stroma for myxoid liposarcoma, and finally the identification of lipoblasts. Eighteen FNAs of lipomas and 17 FNAs of nonlipomatous soft-tissue sarcomas were used as controls for evaluation of the same features. The diagnosis of liposarcoma had been rendered on FNA in 7 cases (58%). The diagnosis was suggested in 3 cases (25%), and a suggestion of sarcoma was rendered in 2 cases. Complex capillary networks were identified in 9 of 12 cases (75%); this was seen in 8 of the 10 myxoid liposarcomas and 1 of the 2 well-differentiated neoplasms. Increased cellularity was seen in 7 of 12 cases (58%), metachromatic stroma was seen in 3 of 12 cases (25%), and lipoblasts were identified in 4 of 12 cases (33%). None of the lipomas or sarcomas exhibited a complex capillary network. When capillaries were identified in lipomas, they were straight, with minimal branching. The lipomas did not show evidence of increased cellularity in any cases. Metachromatic stroma was more frequently seen in the nonlipomatous sarcomas than in the liposarcomas. No lipoblasts were identified in any of the control FNAs.