On this page
Study tools
Write your answer
Saved on this device. No marking — you are the marker.
Stem
A 64-year-old man with a history of metastatic prostate cancer presents to the emergency department with three weeks of progressive, nocturnal lower-thoracic back pain unrelieved by rest, followed over four days by heaviness and weakness in both legs and, in the last 24 hours, difficulty passing urine. On examination he is afebrile. Neurological examination reveals a sensory level to pinprick at T10, grade 3/5 power in the lower limbs, brisk knee and ankle reflexes, and extensor plantar responses. There is no saddle anaesthesia. The bladder is palpable.
Questions
a) What is the most likely diagnosis, and what is the single most important investigation? (2 marks)
Malignant spinal cord compression (MSCC) at around T10, in a patient with known metastatic prostate cancer presenting with progressive nocturnal back pain, a sensory level, upper motor neurone signs and urinary retention. The single most important investigation is urgent whole-spine MRI (within 24 hours; sooner as he is deteriorating) — the gold standard and the only modality that reliably demonstrates the cord and the compressing mass.
b) Outline your immediate management before definitive treatment. (3 marks)
- Recognise the emergency and give dexamethasone 16 mg IV immediately (loading dose) to reduce vasogenic cord oedema and pain — this is malignant compression.
- Arrange urgent whole-spine MRI to confirm the level, cause and cord signal change; involve neurosurgery and oncology/clinical radiology early.
- Insert a urinary catheter for retention; institute analgesia (WHO ladder), pressure-area care with log-rolling, DVT prophylaxis, and nursing on a spinal bed.
- Identify and correct hypercalcaemia; check PSA, calcium, SPEP/free light chains and coagulation; plan definitive decompression within 24 to 48 hours.
c) Compare surgical decompression versus radiotherapy for definitive treatment — give the indications for each. (3 marks)
Both must be delivered within 24 to 48 hours. The Patchell trial showed that for single-level MSCC, direct decompressive surgery plus radiotherapy is superior to radiotherapy alone for maintaining ambulation.
- Surgery is preferred for: a single compressive level, an unstable spine, an unknown primary, a radio-resistant tumour (renal, melanoma, sarcoma), or compression by a retropulsed bone fragment.
- Radiotherapy is preferred for: multiple levels, a radiosensitive tumour (breast, prostate, myeloma, lymphoma), a patient unfit for surgery, or a poor projected survival.
d) What is the strongest predictor of his post-treatment neurological outcome, and what is his likely prognosis? (2 marks)
Pre-treatment ambulatory status is the strongest predictor — because he is still (just) able to move his legs, he has a reasonable chance of maintaining or regaining ambulation if decompressed promptly; once paraplegic, recovery is rare. Urinary retention at presentation is an adverse prognostic feature for bladder recovery. Median survival after malignant spinal cord compression is roughly 3 to 6 months, varying with the primary tumour (prostate and breast tend to do better than lung).