This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
Bone marrow in AL amyloidosis shows IM- 
Select and explain. 
A. Bone marrow plasmacytosis, B. Granulomatous reaction, C. Fibrosis, D. Giant cell formation
A: Bone marrow plasmacytosis
Answer: A: Bone marrow plasmacytosis 
Explanation: Answer is option 1, bone marrow plasmacytosis According to an international study, 62 patients with AL amyloidosis, 40 of whom had monoclonal medullary plasma cells. There was complete concordance between the light chain class of the plasma cells in the monoclonal cases and that of the circulating paraprotein in the 22 cases associated with a paraprotein. The remaining 22 patients had polyclonal plasma cells, although a paraprotein was detected in 6. The degree of plasmacytosis was significantly higher among patients with monoclonal plasma cells and correlated inversely with length of survival.