September 2013
Authors: Matthew A Smith, MD, Alka Palekar MD, and Walid Khalbuss MD PhD FIAC; University of Pittsburgh, Pittsburgh, PA; USA.

Reviewer: Syed Z. Ali, MD, FRCPath, FIAC

Case History: A 52 year-old man presents with a level T-9 paraspinal mass at the site of a previous spinal surgery. A fine needle aspiration and tissue core biopsy was performed. Case Images:

Figure 1: CT-guided fine needle aspiration of the paraspinal mass. (Diff Quik stain, Original magnification x100)

Figure 2: CT-guided fine needle aspiration of the paraspinal mass. (Diff Quik stain, Original magnification x400).

Figure 3: CT-guided core biopsy of the paraspinal mass, touch preparation (Diff Quik stain, Original magnification x200)

What is the best diagnosis of this case?