Differential Diagnosis for 70-year-old Female with Forearm Lump
Single Most Likely Diagnosis
- Hematoma: Given the history of a fall 15 days ago and the presence of a lump on the forearm with ecchymosis and mild tenderness, a hematoma is the most likely diagnosis. The timing and location of the lump, directly beneath the elbow where she landed, support this diagnosis.
Other Likely Diagnoses
- Ulnar nerve injury or neuritis: The location of the lump and symptoms could also suggest an ulnar nerve injury, especially if the patient experienced any numbness, tingling, or weakness in the hand or forearm, although these symptoms are not mentioned.
- Fracture or non-union of a fracture: Although the patient does not report significant pain or deformity, a fracture, especially of the olecranon or the ulna, could present with a lump, particularly if there was displacement or if the fracture is not healing properly.
- Soft tissue injury (e.g., contusion, sprain): The symptoms could also be consistent with a soft tissue injury that has resulted in swelling and ecchymosis.
Do Not Miss Diagnoses
- Compartment syndrome: Although less likely given the time frame and the description of mild tenderness, compartment syndrome is a serious condition that requires immediate attention. It could present with pain out of proportion to the injury, pallor, paresthesia, poikilothermia, and pulselessness.
- Infection (e.g., abscess, cellulitis): An infection could develop in the area of the hematoma, especially if the skin was broken during the fall. Signs of infection would include increased redness, warmth, swelling, and possibly fever.
- Vascular injury: Injury to the brachial artery or its branches could lead to significant complications, including ischemia of the forearm or hand. This would be more likely if there were symptoms of decreased perfusion.
Rare Diagnoses
- Tumor (e.g., lipoma, cyst): Although very unlikely given the acute presentation following trauma, a pre-existing tumor could potentially become more noticeable after a fall.
- Foreign body reaction: If the patient had a foreign object embedded in the forearm during the fall, this could lead to a localized reaction and swelling.
- Olecranon bursitis: Inflammation of the bursa over the olecranon could present as swelling in this area, although it is typically associated with more significant swelling and possibly a history of repetitive elbow trauma.