This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Russell’s body is found in: 
Select and explain. 
A. Metastatic calcification, B. Plasma cells, C. RBC, D. Mast cells
B: Plasma cells
Answer: B: Plasma cells 
Explanation: Russell bodies are large homogenous eosinophilic inclusions formed by hugely distended endoplasmic reticulum of plasma cell.
Their formation is triggered by synthesis of excessive amount of normal secretory proteins in plasma cells.