Fig. 4.
Histologic features typical of SDH-deficient GISTs. A. Multinodular, “plexiform” muscularis propria involvement. B. An example showing an organoid pattern with mixed epithelioid and spindled cytology. C. Epithelioid hypercellular cytology was the predominant finding. D. Marked nuclear pleomorphism was a rare finding. An atypical mitotic figure is seen right to the center.