PAX5 and Hodgkins lymphoma: It should be noted that although the morphological appearances of the original epidural biopsy were concerning for HL, and a very small minority of HL cases can be PAX5 negative, the combination of negative staining for both CD15 and PAX-5 in this first biopsy in conjunction with the poorly preserved morphology, meant it was not felt possible to make a formal diagnosis on this tissue.