Rheumatoid nodule, unspecified knee

This code signifies the presence of a rheumatoid nodule, a subcutaneous granulomatous lesion, specifically located on an unspecified knee. These nodules are a common extra-articular manifestation of rheumatoid arthritis, often firm and non-tender.

Use this code when documentation confirms a rheumatoid nodule affecting the knee, but the laterality (right or left) is not specified. Supporting documentation would include physician notes detailing the physical examination findings or imaging reports identifying the nodule.

• Ensure the documentation explicitly states "rheumatoid nodule" and specifies the knee as the location.
• If laterality (right or left knee) is documented, use the more specific codes M06.361 or M06.362.
• Always code the underlying rheumatoid arthritis (e.g., M05.xx or M06.xx) as the primary diagnosis when applicable, with the nodule as a secondary diagnosis.