Anatomic pathology selected abstracts
April 2023—Kaposi sarcoma can pose diagnostic challenges in biopsy specimens. Multiple histologic variants of cutaneous Kaposi sarcoma (KS) have been described. However, the histomorphologic spectrum of gastrointestinal KS has not been systematically studied. The authors presented a large multi-institutional case series that comprehensively evaluated 46 cases of KS involving the GI tract and identified seven histomorphologic variants, some of which had not previously been described. Five of the variants—lymphangioma/lymphangiectatic like (n=17), mucosal hemorrhage/telangiectatic like (n=17), mucosal inflammation like (n=15), granulation tissue like (n=13), and mucosal prolapse like (n=4)—were inconspicuous but had unique morphologic patterns. These variants easily can be misdiagnosed or misinterpreted on routine examination if KS is not considered and if the IHC stain for human herpesvirus-8 is not utilized.