I got the same thing this morning when I got out of bed. It's on the left side of my left thigh right where it joins my butt. It feels like someone jabbed 30 needles into my skin. It's happened several times today when I stand up from sitting. I'm a 64 year old woman. What's up? I wondered it if was shingles or something like that.
Why no information about this? I just found this post because I woke up this morning with exactly this kind of "sharp, needle-like pain in the buttocks" (left side in my case), which has recurred several times during the day..and not only when sitting. It's really distractingly painful...scary! but very exquisitely localized, like a needle point. Feels like it might be up to a centimeter deep into the muscle, although I suppose it could well be a deep cutaneous nerve response. I had visions of a parasitic worm wiggling out of a blood vessel, or an ingrown hair. I found this site by googling "sharp pain in buttocks" and was gratified to find this page. But disappointed that there is no medical response. (I'm 70 years old, in perfect health, but have never experienced this kind of pain.)