Geographic location? By the way there is also this forum: Palms and Cycads Forum - GardenWeb

That looks to be what is known as a bottle palm, Hyophorbe lagenicaulis. I have no idea what fugal diseases they may contract but they are not very hardy and easily cold damaged by temperatures below freezing. Depending on your location, that possibility could account for the rotted out portion. With only a single frond and such severe vascular damage, I doubt your tree has much hope of survival.

Thank you for the response. Looks like I should toss then. I found it remarkable that there are any green palm leaves still growing out of it. This bottle palm is located in Miami. I was thinking the damage could have been done by some insects but there was no preponderance of fungus in the damage area nor insects in the vicinity so it remains a mystery what caused that damage. If anyone else has any comments to add, they are always welcome. Outside of that, I will coordinate removal within the year.