Differential Diagnosis for a Swollen Lymph Node vs. Hematoma in the Right Pelvic Region
Single Most Likely Diagnosis
- Hematoma: Given the history of a recent right adductor muscle strain, a hematoma is the most likely diagnosis. The presence of a tender, immovable lump in the area of injury, even without visible bruising, supports this diagnosis. Hematomas can form deep to the skin and may not always be accompanied by superficial bruising.
Other Likely Diagnoses
- Swollen Lymph Node: Although less likely given the context of a recent muscle strain, a swollen lymph node could still be considered, especially if there were any signs of infection or other systemic symptoms. However, the direct correlation with the injury site and the absence of systemic symptoms make this less probable.
- Muscle Contusion or Myositis Ossificans: These conditions could also present as a lump following a muscle strain. Myositis ossificans, in particular, is a consideration if the lump develops over time after the initial injury, as it involves the formation of bone tissue within the muscle.
Do Not Miss Diagnoses
- Compartment Syndrome: Although rare and less likely given the description, compartment syndrome is a serious condition that requires immediate attention. It could present with pain out of proportion to the injury, pallor, poikilothermia, paresthesia, and pulselessness. The absence of these specific signs does not entirely rule out compartment syndrome, making it a "do not miss" diagnosis.
- Infectious Process (Abscess): An abscess could form in the soft tissues following a traumatic injury, especially if the skin was broken. While less likely without signs of infection (fever, redness, warmth), it's crucial not to miss this diagnosis due to its potential for serious complications.
Rare Diagnoses
- Soft Tissue Sarcoma: Extremely rare, but a new lump in the soft tissues could potentially be a soft tissue sarcoma. This would be unlikely without a longer history of the lump's presence and other systemic symptoms.
- Vascular Injury (Pseudoaneurysm or Arteriovenous Fistula): These are rare complications of traumatic injuries and could potentially present as a lump. They are more likely to be associated with signs of vascular compromise or abnormal blood flow.