A tale about an unusual cause of pygalgia in non-radiographic axial spondyloarthritis.

Schwannoma are tumors of Schwann cells of the peripheral nerve sheath. Sacral location is rarely reported especially in spondyloarthritis patients. Herein, we report a case of uncommon pygalgia in a 25-year-old man with history of a non-radiographic axial spondyloarthritis and in whom the diagnosis of sacral Schwannoma was established.