Differential Diagnosis for Tiny 2 mm Ossicles at the Dorsal Ulnar Margins

• Single Most Likely Diagnosis
  • Ossicles associated with the extensor carpi ulnaris (ECU) tendon: These small bony structures are commonly found at the dorsal ulnar margin of the wrist and are associated with the ECU tendon. They can be considered a normal anatomical variation but may sometimes cause symptoms if they become inflamed or irritated.
• Other Likely Diagnoses
  • Sesamoid bones: Although less common in this specific location, sesamoid bones can form in various tendons around the wrist, potentially causing similar findings.
  • Accessory ossicles: These are small, extra bones that can be found in various locations around the body, including the wrist. They might be mistaken for fractures or other pathologies but are usually benign.
• Do Not Miss Diagnoses
  • Osteochondroma: A type of benign bone tumor that could present as a small ossicle. Although rare, missing a diagnosis of osteochondroma could lead to unnecessary complications if it grows or becomes malignant.
  • Fracture fragment: A small fragment from a fracture of one of the carpal bones or the ulna could mimic a tiny ossicle. Missing this diagnosis could lead to improper healing or chronic pain.
• Rare Diagnoses
  • Synovial chondromatosis: A condition where cartilage forms within the synovial membrane of a joint, potentially leading to the formation of small ossicles. This condition is rare and usually presents with more significant joint symptoms.
  • Turret exostosis: A rare condition characterized by the formation of a bony growth (exostosis) that can occur after a traumatic event, potentially appearing as a small ossicle at the dorsal ulnar margin of the wrist.