A 50-year-old gentleman presents to his GP with back pain. Work through the case to reach a diagnosis.
“This morning I was lifting a TV out of my car when I suddenly developed really awful back pain. It’s been there ever since and I’m struggling to deal with it.”
Explore the details of the back pain
Use SOCRATES to gain further details about the patient’s back pain.
Where is the back pain?
Did it come on suddenly or gradually?
What kind of pain is this? (e.g. sharp, aching, burning)
Is it continuous or intermittent?
Does the pain move anywhere else?
Are there any other symptoms that seem associated (e.g. weakness, numbness, saddle anaesthesia, urinary or faecal incontinence, weight loss, fevers, sweats)?
When exactly did it start?
Does anything make it better or worse?
Is it worse when you walk, sit down or lay flat?
On a scale of 1-10, how bad is the pain? Is it getting better or worse?
Check if the patient has experienced similar symptoms previously:
Have you experienced back pain in the past?
Was it similar to what you are currently experiencing?
“The back pain started as soon as I lifted the television this morning and I felt a click. There is a constant ache and then sharp pain whenever I try to bend. The pain is in the lower back and it does not shoot down the leg. Paracetamol, ibuprofen and a heat pack have helped a little bit, but not much. I’ve had the ‘usual’ joint aches here and there but nothing this bad ever. I don’t have any weakness or numbness and I’ve opened my bowels today without any issues, I’m also passing water fine. I haven’t noticed any weight loss, fevers or sweats. The pain is definitely worse when I bend, lying still seems to help a little bit. The pain is about 8 out of 10 at its worst.”
Not all of these investigations are warranted immediately (e.g. HIV/ACE) and the choice of investigations should be informed by clinical suspicion.
NaCl (0.9%) can be used to rehydrate the patient and encourage urinary excretion of calcium.
Fluid balance should be closely monitored to avoid overloading the patient.
Bisphosphonates (e.g. Pamidronate) reduce bone turnover and can be used for short-term treatment of hypercalcaemia, once patients have been rehydrated.
Pamidronate also has an analgesic effect on vertebral fractures.
The patient is admitted to hospital and his nephrotoxic medications (ACE inhibitor and NSAIDs) are stopped.
His hypercalcaemia is managed successfully with IV fluids and pamidronate.
Further investigations reveal the following:
PTH – 0.5 pmol/L (1.05 – 6.83)
IgG – 59 g/L (5.9-15.6)
IgA – 0.5 (0.6-5)
IgM – 0.3 (0.4-2.3)
Serum electrophoresis – a band in the gamma region is noted
Immunofixation – IgG Kappa paraprotein is detected totalling 52g/L
The most likely diagnosis is multiple myeloma (a.k.a. plasma cell myeloma).
Multiple myeloma involves the clonal proliferation of plasma cells.
An initiating event occurs which gives a specific plasma cell a survival advantage (e.g. chromosomal translocation). As a result, normal mechanisms to reduce proliferation are overcome and the plasma cell clone begins to proliferate.
CRAB is a useful mnemonic to help remember the most common features of myeloma:
HyperCalcaemia – cytokines result in osteoclast dysregulation
Renal failure – light chains clog up the renal tubules
Anaemia – the bone marrow becomes overcrowded with plasma cells
Bone lesions – cytokines result in osteoclast dysregulation
A bonemarrowaspirate and trephinebiopsy looking for a clonal plasma cell proliferation are needed to confirm the diagnosis.
A skeletalsurvey is also required to stage the disease.
Symptomatic myeloma criteria
The below criteria must be met for a diagnosis of symptomaticmyeloma: 3
Clonal plasma cells >10% on bone marrow biopsy or in a biopsy from other tissues.
A monoclonal protein (paraprotein) in either serum or urine (unless non-secretory, in which case there need to be >30% clonal plasma cells in the bone marrow).
Evidence of end-organ damage felt related to the plasma cell disorder (e.g. CRAB).
This type of myeloma is often referred to as smouldering myeloma. It differs from symptomatic myeloma because of the absence of end-organ damage.
The below criteria must be met for a diagnosis of asymptomaticmyeloma: 3
Serum M paraprotein (IgG or IgA) >30 g/L or urinary M protein ≥500 mg per 24 hours and/or clonal bone marrow plasma cells 10-60%.
No myeloma-related organ or tissue impairment, or amyloidosis.
Myeloma is currently an incurabledisease that is chronic, relapsing and remitting. Treatment is aimed at controllingthedisease, prolongingsurvival and maximisingqualityoflife.
This gentleman has symptomatic myeloma and therefore requires active treatment.4
Treatment choice is based upon the age and fitnesslevel of the patient.
Younger patients (< 65 years or < 70 years and in a good clinical condition):
Induction chemotherapy (bortezomib & dexamethasone) followed by high-dose therapy with autologous stem cell transplantation (ASCT) is the standard treatment.
This would be the most appropriate choice for the patient in this scenario.
Chemotherapy alone without ASCT transplant
Bortezomib, melphalan and prednisone
Alternative regime – lenalidomide plus low-dose dexamethasone
Radiotherapy can be used if there is focal bony pain/plasmacytoma.
Lenalidomide has been approved as monotherapy for the maintenance treatment of younger adult patients with newly diagnosed myeloma who have undergone autologous stem cell transplantation. Maintenance therapy is not recommended for elderly patients.
Patients who have undergone myeloma treatment (and those with smouldering myeloma) should be reviewed at least every 3 months, including assessment of the following:
Myeloma symptoms and treatment side effects (e.g. fatigue, bony pain)
FBC, renal function, bone profile, serum immunoglobulins and serum protein electrophoresis