Differential Diagnosis for Low Back Spasm with Mobile, Painful Masses
- Single most likely diagnosis:
- Muscle knots or trigger points: The description of "two tight balls" that move when massaged and cause pain is highly suggestive of muscle knots or trigger points, which are common causes of low back pain and can be palpable and tender.
- Other Likely diagnoses:
- Fibromyalgia: While less specific, the presence of tender points that are painful to the touch could suggest fibromyalgia, especially if the patient has a history of widespread pain and other symptoms like fatigue and sleep disturbances.
- Piriformis syndrome: This condition, where the piriformis muscle irritates the sciatic nerve, can cause pain and tightness in the buttock area that might feel like "tight balls" and could radiate to the low back.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Abdominal aortic aneurysm (AAA): Although the description doesn't classically suggest AAA, any acute onset of severe back pain, especially if accompanied by abdominal pain or other systemic symptoms, warrants consideration of this potentially life-threatening condition.
- Spinal epidural abscess: This is a rare but serious condition that can present with back pain and might have a palpable mass if there is significant soft tissue involvement. Fever, neurological deficits, or severe pain would increase suspicion.
- Rare diagnoses:
- Soft tissue tumors (e.g., lipoma, sarcoma): While rare, soft tissue tumors could present as palpable masses that are painful, especially if they impinge on surrounding structures.
- Myofascial pain syndrome due to underlying conditions (e.g., inflammatory arthritis): Certain conditions can lead to myofascial pain that might present similarly, though the underlying disease would likely have other distinguishing features.