HS can present as a component of systemic autoinflammatory syndromes like pyoderma gangrenosum, acne, pyogenic arthritis, and HS (PAPASH) and pyoderma gangrenosum, acne, and HS (PASH), which are caused by mutations in PSTPIP1 (46, 47). This evidence concerns the gene PSTPIP1 and histiocytic sarcoma.