Grafted frozen-thawed ovarian tissue from a leukemia patient. (A) Histologic analysis of a frozen-thawed ovarian fragment from a leukemia patient recovered from a mouse after 6 months' xenografting. Normal ovarian stroma is no longer present, and a human follicle encircled by a large number of proliferating malignant lymphocytes can be seen (scale bar = 20 μm). (B) Large, white, burgeoning mass that corresponded to massive peritoneal invasion by leukemic cells.