Doublecortin immunolabeling and lack of neuronal nuclear protein immunolabeling in feline gliomas.

Doublecortin (DCX) and neuronal nuclear protein (NeuN) can be used as immunomarkers of neuronal progenitor cells and mature neurons, respectively. Increased DCX immunolabeling has been associated with tumor invasion in human gliomas and anaplastic canine meningiomas. These immunomarkers have not been assessed in feline gliomas. Here we characterized the DCX and NeuN immunohistochemistry (IHC) profile in 11 feline gliomas (7 oligodendrogliomas, 4 astrocytomas). Immunolabeling was classified according to intensity (weak, moderate, strong), distribution of neoplastic cell immunolabeling (1 = <30%, 2 = 30-70%, 3 = >70%), and predominant location within the neoplasm (random or at tumor margins). DCX immunolabeling was strong in 6 cases, weak in 4 cases, and moderate in 1 case. The distribution of DCX immunolabeling was characterized as 1 (4 cases), 2 (4 cases), and 3 (3 cases). DCX immunolabeling occurred predominantly in astrocytomas, which had stronger immunostaining at the tumor margins. NeuN immunolabeling was absent in all cases. Our IHC findings are similar to those reported for DCX and NeuN IHC in canine gliomas. The increased DCX immunolabeling at tumor margins is similar to labeling in invasive human gliomas and anaplastic canine meningiomas.