Dark brown spot on top of potted cactus.

[Kelsanus]

Help! I am not sure what is wrong with my Cactus! It has recently developed a dark brown spot on the top and I am not sure if it is rotting or has a disease! I have been checking online and haven't found any similar posts!

[iann]

I don't like that. It might be some minor damage from a pest, scorch, etc. Or it might be rotting. Check carefully, and if it is mushy or becomes mushy then you have to chop it out.