Other cyst of bone, other site

This code signifies the presence of a non-neoplastic, fluid-filled or semi-solid sac within bone tissue, excluding aneurysmal bone cysts, solitary bone cysts, and osteofibrous dysplasia. These cysts are typically benign and may be discovered incidentally or due to symptoms like pain or pathological fracture.

Apply this code when documentation specifies a bone cyst that does not fit the descriptions for solitary, aneurysmal, or osteofibrous dysplasia, and is located in an anatomical site other than the shoulder, upper arm, forearm, hand, thigh, lower leg, ankle, or foot. Supporting documentation should clearly identify the cyst as "other" or "unspecified" type and confirm the "other site" location.

• Ensure the documentation explicitly rules out solitary bone cyst (M85.5-) and aneurysmal bone cyst (M85.5-) before using this code.
• Verify the anatomical site. If a more specific site is documented (e.g., shoulder, hand), a more specific code within M85.6- should be used.
• This code is for the cyst itself; if a pathological fracture is also present, an additional code for the fracture should be assigned.