Question: The surgeon excised a lipoma from a patient's back measuring 5.0 cm x 4.0 cm x 2.0 cm. Should we select 21930 or 11406 for this procedure? New York Subscriber Answer: The key to determining the correct code is the excision's depth. Assuming that the depth in this case is 2.0 cm (20 mm) -- which is greatly in excess of the skin's average thickness (2-3 mm) -- you are justified to report 21930 (Excision, tumor, soft tissue of back or flank). Although lipomas are usually found below the skin (and some sub-fascial/intramuscular varieties may be quite deep), skin lipomas do exist. If the physician documentation describes a skin lipoma (excision depth no greater than about 4 mm), you should rely on the benign lesion codes, such as 11406 (Excision, benign lesion including margins, except skin tag [unless listed elsewhere], trunk, arms or legs; excised diameter over 4.0 cm).