Differential Diagnosis for 37yo Male with Back Pain

The patient presents with lower left back pain radiating to the left hip, leg, and groin for 3 weeks without systemic symptoms like fever or difficulty voiding, and a negative urine dip. Here's a structured approach to the differential diagnosis:

• Single Most Likely Diagnosis

  • Lumbar Disc Herniation: This is the most likely diagnosis given the radiation of pain to the hip, leg, and groin, which suggests nerve root impingement. The absence of systemic symptoms and negative urine dip further supports this diagnosis, as it points away from infectious or urinary causes.

• Other Likely Diagnoses

  • Lumbar Strain: Given the acute onset and location of pain, a lumbar strain is a plausible diagnosis. However, the radiation of pain to the leg and groin might suggest a more specific nerve root involvement.
  • Degenerative Disc Disease: This condition can cause chronic back pain and, if severe, can lead to nerve root compression, explaining the radiation of pain.
  • Sacroiliitis: Inflammation of the sacroiliac joint can cause lower back pain that radiates to the hip and groin. However, it's less likely to cause leg pain unless there's significant inflammation affecting nearby nerves.

• Do Not Miss Diagnoses

  • Cauda Equina Syndrome: Although less likely, this is a medical emergency that requires immediate attention. Symptoms can include severe low back pain, bilateral leg pain, and difficulty with bladder and bowel function. The absence of difficulty voiding and fever makes this less likely, but any suspicion warrants urgent investigation.
  • Spinal Infection (e.g., Discitis or Osteomyelitis): Despite the absence of fever, spinal infections can present subtly and are critical to diagnose early. Risk factors such as recent travel, immunocompromised state, or intravenous drug use would increase the likelihood.
  • Testicular Torsion: Although the patient's pain is primarily back pain, testicular torsion can sometimes present with referred pain to the lower back or abdomen. It's a surgical emergency, and any suspicion warrants immediate evaluation.

• Rare Diagnoses

  • Spinal Tumors: Both primary and metastatic tumors can cause back pain and neurological symptoms. They are less common but should be considered, especially if there's a history of cancer or if the pain is worsening over time.
  • Aortic Aneurysm or Aortic Dissection: These conditions can cause severe back pain and are life-threatening. They might not typically cause radiating pain to the leg and groin but should be considered in the differential, especially if there are risk factors such as hypertension or atherosclerosis.
  • Piriformis Syndrome: This involves compression of the sciatic nerve by the piriformis muscle, leading to buttock and leg pain. It's less common and might not fully explain the groin pain but could be considered if other diagnoses are ruled out.