Pyoderma gangrenosum is a skin disease characterized by wounds with 
blue-to-purple undermined borders surrounding purulent necrotic bases. This 
article reports on a patient with a circumferential, full-thickness, and 
partially necrotic lower-extremity ulceration of unknown etiology. Results of 
laboratory tests and arterial and venous imaging studies were found to be within 
normal limits. The diagnosis of pyoderma gangrenosum was made on the basis of 
the histologic appearance of the wound tissue after biopsy as a diagnosis of 
exclusion. Negative pressure wound therapy was undertaken, which saved the 
patient's leg from amputation. Although negative pressure wound therapy has 
demonstrated efficacy in the treatment of chronic wounds in a variety of 
circumstances, this is the first documented use of this technique to treat an 
ulceration secondary to pyoderma gangrenosum.