ICD-10-CM > M00-M99 > M80-M85 > M85 > M85.5 > M85.56 M85.56 Aneurysmal bone cyst, lower leg Non-Billable/Non-Specific Codes M85.561Aneurysmal bone cyst, right lower legM85.562Aneurysmal bone cyst, left lower legM85.569Aneurysmal bone cyst, unspecified lower leg