Benign Fibrous Histiocytoma of the Sacrum – Diagnostic Difficulties Facing This Rare Bone Tumor

Abstract

Benign fibrous histiocytoma of bone is rare, and this is the first report of the tumor arising from the sacrum. The descriptive histopathological picture makes the diagnosis more difficult as it resembles many benign and malignant myxoid tumors. In this case report, the diagnostic difficulties involved and a review of the literature in order to describe the optimal management of this condition, have been presented. The clinical presentation of this 18-year-old girl was that of low back ache, radiating along the right posterior leg, of 1 month’s duration. On the straight leg raising test, right-sided sciatic nerve compression was detected. Magnetic resonance imaging revealed a large tumor involving and destroying sacral segments S₃–S₄, homogeneous in intensity and extending into the vertebral canal and the presacral space. There was no enhancement with gadolinium contrast. Core needle biopsy revealed fibrous histiocytoma. Excision through a posterior midline incision was performed taking care to preserve the S₁–S₂ sacral segments and also the sacral nerves. Additional cauterization with phenol was performed. Postoperatively, the patient had significant improvement in pain with no major residual neurological deficit.