This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Prostate Cancer, Subject name: Surgery
Ca prostate most common metastasis to - 
Select and explain. 
A. Skull, B. Femur, C. Lumbar spine, D. Sacrum
C: Lumbar spine
Answer: C: Lumbar spine 
Explanation: Ans. is 'c' i.e.' Lumbar spine "Lymphatic metastases are most often identified in the obturator lymph node chain _____Smith so Most common metastatic sites of prostate carcinoma are lymph nodes & bones,o Lymphatic metastasis occurs most commonly to - obturator lymph nodes,o Other lymph nodes involved are :Common iliacPresacralPeriaorticAlso Remembero Most common bony metastasis occurs in (in decreasing order)Lumbar spine (most common)Proximal femurPelvisThoracic spineRibsSternumSkullHumerus (Smith s Urology? 17/e)o The bone lesions of metastatic carcinoma prostate are typically osteoblastic,o Visceral metastases most commonly involve the lung, liver, and adrenal gland.