Osteosarcoma diagnosed in a dog using a formalin-fixed fine-needle aspirate biopsy.

The CytoHisto technique is minimally invasive and allows for sectioning similar to a full-thickness excisional or incisional biopsy with subsequent H&E and IHC staining, and special stains allow for a definitive diagnosis of osteosarcoma. The CytoHisto technique is a practical diagnostic technique to pursue in clinical practice that minimizes patient invasiveness and maximizes sample collection time, similar to the routine FNA technique.