Babak Mirzashahi - Joint Research Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
Abbas Tafakhori - Tehran University of Medical Sciences, Tehran, Iran
Arvin Najafi - Joint Research Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
Mahmoud Farzan - Joint Research Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran

  Even though intervertebral disc degeneration can be found in the natural course of alkaptonuria, detection of the disease by black disc color change in a patient without any other presentation of alkaptonuria is an exceptionally rare condition. We have reported a very rare case of alkaptonuria presented with low back pain and steppage gait in a ۵۱-year-old male with a complaint of chronic low-back pain and steppage gait who was operated on for prolapsed lumbar disc herniation. Intraoperatively his lumbar disk was discovered to be black. The alkaptonuria diagnosis was considered after histopathological examination of the black disc material and elevated urinary concentration of homogentisic acid confirmed the diagnosis. To our knowledge, this presentation has not been reported previously in literature.    

Alkaptonuria, Black disc material, Herniation, Lumbar disc, Ochronosis, Steppage gait