The microscopic features and clinical course of this neoplasm have been comprehensively explained by Heffner, who considered it "low-grade adenocarcinoma of likely ELS origin." The papillary form more commonly affects females, and it is a more aggressive form of ELST that is destructive and exhibits extensive local spread. The tumor usually has a close association with von Hippel-Lindau (VHL) disease, but 11%-30% of the ELST cases develop in individuals without a VHL mutation. The gene discussed is VHL; the disease is neoplasm.