AGE: 3 Year
Source / History:
Skull mass. History of a mass caudal to the skull, first noticed 2
years ago. No change in the lesion since then.
The submitted smears are of moderate to high cellularity containing cells in good morphologic condition. The nucleated cells are composed of numerous atypical cells with scattered nondegenerate neutrophils in numbers similar to the amount of peripheral blood. The atypical cells are arranged as individual cells and in loosely adherent clusters, they exhibit moderate pleomorphic features. The atypical cells are often associated with brightly eosinophilic matrix material. This matrix material sometimes forms eosinophilic fibrils and is also readily found in the background of the sample. The atypical cells are round or spindle shaped with moderate amounts of wispy, basophilic cytoplasm that often have several clear cytoplasmic vacuoles. The cytoplasm also occasionally have magenta granules. These cells have round or oval nuclei that contain finely stippled chromatin with prominent, deeply basophilic nucleoli. Nucleoli are often multiple, sometimes of variable size in the same nucleus, and often angular. The background of the sample contains numerous RBCs with a heavy eosinophilic matrix of proteinaceous fluid.
Microscopic Interpretation (Cytology)
Atypical spindle cells, probable malignant mesenchymal neoplasm with mild inflammation
The spindle cells exhibit sufficient atypical features for an interpretation of a malignant mesenchymal neoplasm. A prominent feature of this sample is the presence of abundant matrix material. Possible differentials for this neoplasm include multilobular tumor of bone, chondrosarcoma, osteosarcoma, chordoma or mesenchymal tumors. If possible, excision of this lesion is recommended with histologic confirmation of the interpretation. For customers not currently viewing this pathology report in VetConnect PLUS, please log onto www.vetconnectplus.com today to see the image associated with this case, at no additional cost. If you need help logging on, please call IDEXX Customer support at 1 888-433-9987.