Illinois Subscriber
Answer: In this case, -superficial- vs. -deep- is a product of distance from the surface (for instance, skin is superficial, bone is deep), rather than a description of the muscle (in other words, just because the quadriceps is a -superficial- muscle doesn't mean you can't perform a deep biopsy on it).
Bottom line: The actual muscle the surgeon biopsies (such as biceps, quads, etc.) isn't the issue -- rather it is how much dissection and how many other structures would have to be dealt with to access the biopsy site.
The surgeon's clinical judgment may serve as a guide, but as a general rule, you should choose 20205 (Biopsy, muscle; deep) for tissue obtained deep below the fascia, under another layer of muscle or behind bone, while you should choose 20200 (- superficial) for tissue taken just below the surface of the skin or superficially just below the muscle fascia.