Application of a novel immuno histochemical panel for the differential diagnosis of Canine Sterile Granulomas

Cutaneous Sterile Granuloma/Pyogranuloma Syndrome (SGPS) and Reactive Histiocytosis (RH) are two uncommon cutaneous disorders of dogs that may show similar clinical and histopathological features.
SGPS is characterized by an inflammatory infiltrate consisting mostly of macrophages intermingled with neutrophils, lymphocytes and plasma cells; RH is characterized by nodular to diffuse infiltration of dermal dendritic cells that accumulate in tumor - like configurations.
In the last stage of RH, the increased number of macrophages can make a differential diagnosis with SGPS difficult.