Macroscopic and histologic analysis of ovarian fragments recovered from the mice after 6 months' grafting. (A) Macroscopic view of normal frozen-thawed ovarian grafts. (B) Macroscopic view of an enlarged ovarian graft. Note the stitches at both ends. (C) Histologic aspect of a normal ovarian-xenografted fragment. Five ovarian follicles can be recognized in a cellular stroma surrounded by a fibrotic area. Original magnification ×100. (D) Human ovarian graft from a patient with ALL with massive cellular invasion. Note the 6-0 Prolene stitch in the graft (arrow). Original magnification ×50. (E) Human follicle encircled by a large number of lymphocytes. Normal ovarian stroma is no longer present. Original magnification ×100. (F) Massive lymphocytic invasion of the ovarian graft. The histologic abnormalities observed in these lymphocytes were identified as malignant in nature and attributed to leukemic invasion. Original magnification ×200.