The AMD A10 APUs can run hot, but your temperatures seem a bit extreme. Install AMD Overdrive - it will report the thermal margin available for your APU, i.e., how much hotter your APU can get before it begins to throttle back to reduce heat.
Do you have a way of measuring the heatsink temperature? If the CPU is hot, but the heatsink base is cool, that means you have poor thermal coupling between the CPU and the heatsink - remove, clean, reinstall thermal interface compound, and check again. If the heatsink is hot (only a couple of degrees below the CPU), that means you have good thermal coupling between the CPU and the heatsink, but the heatsink cannot transfer its thermal energy to the ambient environment. This indicates either an airflow issue or that the heatsink is undersized for your CPU's thermal load.
I just built a system with the A10 7860K APU, cooled with the Noctua NH-L9a 92mm low-profile CPU cooler. I used a slim microATX case, and couldn't tolerate a tall heatsink/fan unit. My APU idles in the 30C range, and hits ~50C under full load (Prime95).
Just for grins, I used a thermal imager to inspect my motherboard & APU/heatsink set-up. The imager reported temperatures consistent with what the motherboard utility (A-Tuning from ASRock) measured. It also showed me that some of the inductors in the VRM were hitting 65C (too hot to touch comfortably), and a small voltage regulator was hitting 70C.