Differential Diagnosis for a Painful Mass on the Dorsum of the Wrist

• Single Most Likely Diagnosis
  • Ganglion Cyst: This is the most likely diagnosis given the description of the mass as tender, firm, translucent, and not freely movable, located on the dorsum of the wrist. Ganglion cysts are common in this area, especially in young adults, and are known for their characteristic appearance and location.
• Other Likely Diagnoses
  • Extensor Tenosynovitis: Although less likely than a ganglion cyst, extensor tenosynovitis could present with a painful mass on the wrist, especially if there's inflammation of the tendon sheath. However, it might be more associated with pain on movement and less likely to be described as a firm, translucent mass.
  • Lipoma: A lipoma could be considered, but it's less likely given the specific location on the dorsum of the wrist and the description of the mass being tender and firm. Lipomas are typically soft and less commonly found in this specific location.
• Do Not Miss Diagnoses
  • Rheumatoid Nodule: Although less common, especially in a 17-year-old without a history of rheumatoid arthritis, a rheumatoid nodule could present as a firm mass. It's crucial to consider this diagnosis due to its implications for underlying disease, even though the patient's age and lack of past medical history make it less likely.
  • Tophus: A tophus, associated with gout, is unlikely in a young female without a history of gout or hyperuricemia but should be considered due to its potential impact on health if missed. Tophi can present as firm, painless masses but can occasionally be painful.
• Rare Diagnoses
  • Other Soft Tissue Tumors: Various rare soft tissue tumors could present as a mass on the wrist, including synovial sarcoma or giant cell tumors of the tendon sheath. These are much less common and would be considered if the mass does not respond to initial treatment or if there are atypical features on imaging or biopsy.