Aneurysmal bone cyst, unspecified shoulder

This code signifies a benign, non-cancerous bone tumor characterized by blood-filled cysts, specifically located in an unspecified shoulder. It represents a localized osteolytic lesion that can cause pain, swelling, and pathological fractures in the affected area.

Apply this code when documentation confirms an aneurysmal bone cyst affecting the shoulder, and the laterality (right or left) is not specified. This diagnosis is typically made based on imaging studies (X-ray, MRI) and often confirmed by biopsy.

• Ensure the documentation clearly states "aneurysmal bone cyst" and specifies the shoulder as the affected site.
• Avoid using this code if laterality (right or M85.511, left or M85.512) is documented; use the more specific code.
• Consider sequencing this code as a primary diagnosis when it is the reason for the encounter, especially for diagnostic workup or treatment of the cyst.