This case report describes the detection of non-Hodgkin lymphoma (NHL) within ovarian tissue after cryopreservation. The 27-year-old woman presented no gynecological symptoms such as pelvic pain or abnormal uterine bleeding. During laparoscopy for ovarian tissue cryopreservation, the ovaries appeared markedly modified and some solid content cysts were highlighted. Microscopically the cysts revealed the presence of lymphoid infiltrate, whereas the histological assessment of some fragments of the ovarian cortical tissue revealed no evidence of pathological lymphoid infiltration. This case report describes the presence of pathological lymphoid infiltration in ovarian cysts but not in the cortical tissue of a young woman with secondary NHL. Despite the absence of the positivity in cortical tissue it was recommended to avoid the cryopreserved ovarian tissue transplantation to reduce the risk of reseeding of the malignancy in the woman.