Challenging differential diagnosis, Rare disease
Mohammed S. Alisi, Munther G. Al-Saber, Ahmed A. Abdulelah, Amer Alqaisi, Tareq M.A. Kanaan, Fadi Hadidi
Department of Special Surgery, Division of Orthopaedics, School of Medicine, The University of Jordan, Amman, Jordan
Am J Case Rep 2020; 21:e924575
Available online: 2020-08-06
Alkaptonuria (AKU) is a rare metabolic disease caused by a deficiency in homogentisic acid oxidase, which leads to the accumulation of homogentisic acid dark pigments in tissues such as bones, ligaments, and tendons. Long-term duration of this condition, termed ochronosis, can result in degenerative arthropathy involving the spine and large joints.
CASE REPORT: This report describes a 55-year-old Jordanian woman presenting with chronic neck and lower back pain. History, physical examination, and radiological imaging indicated cervical myelopathy and lumbar spine degeneration. Two-level anterior cervical discectomy and fusion was performed successfully. Intra-operatively, the cervical discs were observed to be black, suggesting a diagnosis of alkaptonuria, which was later confirmed by genetic testing. A detailed history and physical examination revealed the absence of classical features of AKU.
CONCLUSIONS: Intraoperative detection of black disc material suggests the need for further tests to diagnose AKU, especially in indolent patients who did not have classical clinical features. Surgical management may improve outcomes in patients with cervical myelopathy due to ochronosis.
Keywords: Alkaptonuria, Neck Pain, Ochronosis