Differential Diagnosis

The patient's presentation of severe low back pain, difficulty in ambulation, and electric-like sensations in the legs, along with her complex medical history, suggests a multifaceted differential diagnosis. The following categories outline potential causes for her symptoms:

• Single Most Likely Diagnosis

  • Osteoporotic vertebral compression fracture: Given the patient's history of rheumatoid arthritis (RA), long-term use of aromatase inhibitors (Anastrozole) which can lead to bone loss, smoking, and her postmenopausal status after a history of early hysterectomy and brief use of hormone replacement therapy (HRT), she is at high risk for osteoporosis. The sudden onset of severe back pain, especially during a trivial activity like taking a bath, is consistent with a vertebral compression fracture.

• Other Likely Diagnoses

  • Spinal stenosis: The patient's age, history of RA, and symptoms of difficulty in ambulation accompanied by electric-like sensations in the legs could suggest spinal stenosis, particularly if there's been a recent exacerbation or if the condition has progressed.
  • Disc herniation: Given the acute onset of severe low back pain and radicular symptoms (electric-like sensations), a disc herniation is a plausible diagnosis, especially in the context of degenerative changes that might be present in her spine.
  • Diabetic neuropathy: Although the patient's symptoms seem more localized to the spine, her diabetes could contribute to neuropathic pain, and diabetic neuropathy might exacerbate or mimic some of her symptoms.

• Do Not Miss Diagnoses

  • Spinal epidural metastasis: Given her history of breast cancer, there's a possibility of metastatic disease to the spine, which could cause her symptoms. This diagnosis is critical to rule out due to its significant implications for treatment and prognosis.
  • Infection (e.g., osteomyelitis, discitis): Infections of the spine can present with severe back pain and neurological symptoms. The patient's history of recent surgery and immunocompromised state (due to chemotherapy and possibly RA) increases her risk.
  • Cauda equina syndrome: This is a medical emergency characterized by low back pain, sciatica, and neurological symptoms such as bladder and bowel dysfunction. It requires immediate intervention to prevent permanent damage.

• Rare Diagnoses

  • Multiple myeloma: Although less likely, the patient's age, back pain, and history of breast cancer (which might suggest a predisposition to other malignancies) could raise the possibility of multiple myeloma, especially if there are other systemic symptoms or abnormalities in blood work.
  • Paget's disease of the bone: This condition can cause bone pain and deformities and might be considered in the differential, especially if there are characteristic findings on imaging or elevated alkaline phosphatase levels.