A 68-year-old woman presents with a 3- week history of worsening back pain. For last 3 months, she has been feeling tired and also complaints of gradual tongue thickening. The woman is not on any medication.

She is otherwise well and has not visited GP for more than 5 years for any complaint. Examination She looked pale Tenderness was observed on palpation over her lumbar spine Tongue appearance: Enlarged, with smooth papulo-nodular pink infiltrate disturbing the papillae Mucosal aspect of the lip was extending onto the vermillion lip Cardiorespiratory and abdominal systems was normal Blood analysis indicated: Hemoglobin: 9.7 g/DI  Mean corpuscular volume: 77 WBCs: 4.1 x 10 9 /L Platelet: 138 x 10 9 /L  ESR = 103 mm/h (Normal range: < 10 mm/h) Her potassium, urea, creatinine and liver tests were normal. Sodium was close to the lower threshold (136 mmol/L; Normal range: 135 -145…