For many surgical pathologist, the identification of necrotizing suppurative granulomatous inflammation in a lymph node biopsy is a relatively common occurrence, and often Cat Scratch Disease is high on the list of potential differential diagnostic possibilities. Unfortunately, identification of the etiologic agent of Cat Scratch Disease (Bartonella Henselae) often required PCR or silver stains (such as Warthin-Starry or Steiner) that were often very difficult to interpret. An antibody has recently become available to the Cat Scratch organism, and it has performed very well in ProPath’s in house testing. The number of positive organisms can vary substantially from case to case, and if numerous they can often be appreciated on medium power, where they occur as scattered collections usually localized to the areas showing the most intense suppurative and necrotizing changes. When they are less numerous, they often require examination under high power for identification, although this is still far easier on the eyes than performing the same task with a silver stain.
Date of last revision: June 2000.