Differential Diagnosis for a 72 yo female with a bump on the outer, lateral heel

• Single most likely diagnosis
  • Haglund's deformity or pump bump: This condition is a common cause of a painful bump on the outer heel, often associated with shoe friction and pressure. The absence of a reported injury and the location of the bump make this a likely diagnosis.
• Other Likely diagnoses
  • Bursitis: Inflammation of the bursa near the heel can cause a painful bump, especially if it becomes inflamed due to friction or pressure.
  • Heel fat pad atrophy: As people age, the fat pad under the heel can atrophy, leading to less cushioning and potentially causing pain and bruising, especially if there's a bony prominence.
  • Plantar fasciitis: Although more commonly associated with pain on the underside of the heel, plantar fasciitis can sometimes cause lateral heel pain, especially if the fascia is inflamed near its insertion points.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Tumor (e.g., sarcoma): Although rare, a tumor could present as a painful bump. Given the potential severity of this diagnosis, it's crucial not to miss it, even if it's unlikely.
  • Infection (e.g., cellulitis, abscess): An infection could cause a painful, bruised bump, especially if there's an open wound or compromised skin integrity. Prompt diagnosis and treatment are essential to prevent serious complications.
  • Deep vein thrombosis (DVT): While less common in the heel, DVT could potentially cause swelling, pain, and bruising in the leg, including the heel area. Given the risk of pulmonary embolism, DVT should always be considered.
• Rare diagnoses
  • Rheumatoid nodule: In patients with rheumatoid arthritis, nodules can form over bony prominences, including the heel, causing pain and swelling.
  • Gout or pseudogout: These conditions can cause sudden, severe pain and swelling in joints, including the heel, though they are less common in this location.
  • Erythema nodosum: This condition involves the formation of painful nodules under the skin, often on the shins but potentially elsewhere, including the heel, in response to various triggers, including infections and medications.