Atypical case of diffuse idiopathic skeletal hyperostosis mimicking ankylosing spondylitis in a young woman with polycystic ovary syndrome.

Both diffuse idiopathic skeletal hyperostosis and ankylosing spondylitis present with similar clinical manifestations of restricted spinal mobility and postural abnormalities, and radiographic resemblances including axial spine involvement and enthesopathy. Nonetheless, they are two entirely different diseases. We report an unusual case of DISH in a young woman whose diagnosis was established based on radiologic features. This case report aims to highlight the under-recognised radiologic aspects of the differential diagnosis between DISH and AS in order to avoid an inaccurate diagnosis.