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: Surgery
Serum alkaline phosphate is normal in: September 2009 
Select and explain. 
A. Osteosarcoma, B. Osteomalacia, C. Multiple myeloma, D. Malnutrition
C: Multiple myeloma
Answer: C: Multiple myeloma 
Explanation: Ans. C: Multiple Myeloma I. Increased alkaline phosphatase levels: Increased calcium deposition in bone Hyperparathryroidism Pagets disease Osteomalacia / rickets: in both cases there is failure of mineralization; Caffey's syndrome (infantile coical hyperostosis) Osteoblastic bone tumors (metastatic or osteogenic sarcoma) alkaline phosphatase level is high in about 1/2 of patients with osteosarcoma & in smaller fraction of those with another type of primary malignant bone tumor; Pregnancy Childhood Liver disease such as biliary obstruction Total Parenteral Nutrition (TPN) II. Decreased alkaline phosphatase levels: Malnutrition Excess Vit D ingestion; Hypophosphatasia