UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 0631

Question:
A 75 year old woman complains of weakness and fatigue. On examination she is noted to be pale and she has multiple purpura on her hands and legs and particularly large bruising in the peri-orbital area. A blood picture demonstrates a normocytic, normochromic anemia. A serum protein electrophoretic pattern shows a peak band while immunofixation of the urine reveals an M-protein. A most appropriate next investigation would be

a) anti-mitochondrial antibodies
b) urinary magnesium levels
c) salicylate levels
d) paracetomol levels
e) look for lytic lesions on plain radiographs