The patient went on to have a laminectomy. 

Histology

MICROSCOPIC DESCRIPTION:

The sections show ligamentum flavum, calcified lamellar bone and adjacent connective tissue. There are collections of neutrophils, surrounded by chronic inflammatory cells and fibrosis. No granulomas are seen. There is no evidence of malignancy. The Gram stain shows sparse Gram positive bacterial cocci in the inflammatory exudate.

DIAGNOSIS:

Organizing abscess formation.