Differential Diagnosis for Small Circular Nodules on Tendons with Popping Sensation

• Single most likely diagnosis:
  • Ganglion cysts: These are common, benign lumps that can develop on tendons or joints, often presenting as small, circular nodules. The popping sensation could be due to the cysts rupturing or changing in size.
• Other Likely diagnoses:
  • Tendinosis or tendonitis: Inflammation or degeneration of the tendons can lead to the formation of small nodules, and the popping sensation might be due to the tendon's irregular texture or the formation of scar tissue.
  • Bursitis: Inflammation of the bursae (fluid-filled sacs that cushion joints and tendons) can cause swelling and nodules, potentially leading to a popping sensation.
  • Lipoma: A benign tumor composed of fat tissue, which can develop near tendons and cause a nodule-like appearance, although the popping sensation is less common.
• Do Not Miss diagnoses:
  • Rheumatoid arthritis: Although less likely, rheumatoid arthritis can cause nodules on tendons (rheumatoid nodules) and joint inflammation, which might lead to a popping sensation. Missing this diagnosis could result in delayed treatment and significant morbidity.
  • Gout or pseudogout: These conditions can cause sudden, severe joint pain and swelling, potentially leading to the formation of nodules on tendons. The popping sensation might be due to the sudden release of pressure or the formation of tophi (deposits of uric acid crystals).
• Rare diagnoses:
  • Xanthoma: A rare, benign growth composed of fat-laden cells, which can develop on tendons and cause nodules.
  • Tendon xanthoma: Associated with high cholesterol levels, these are rare, benign growths on tendons that can cause nodules.
  • Sarcoidosis: A rare, autoimmune condition that can cause inflammation and nodules in various parts of the body, including tendons.