A 49 year old man suffering from carcinoma of prostate was x -rayed. He showed areas of sclerosis and collapse of T10 and T11 vertebrae in x-ray. The spread of this cancer to the above vertebrae was through
Sacral canal
Lymphatic vessels
Internal vertebral plexus of veins
Superior rectal vein
Ans. is 'c' i.e. Internal vertebral plexus of veins Prostatic cancer spreads to the bones through blood vessels; first into the periprostatic venous plexus* and then into the internal vertebral plexus of veins. This metastasis is possible because of valveless communication* between the periprostatic and vertebral plexus of veins.Points of importance -Most common sites * of bony metastasis for prostatic CA-: Lumbar vertebrae > Proximal femur > Pelvis Bony metastasis of prostate CA are mainly osteoblastic* and cause sclerotic lesions.
Prostate Cancer