The appendix and ovaries are rarely involved simultaneously in malignancies. The decision to perform an ovarian biopsy or a surgical resection in young patients can be challenging without sufficient clinical information.

We describe an 11-year-old girl with bilateral ovarian masses, an enlarged appendix, associated pleural effusion, and ascites. Appendectomy and biopsy of the bilateral ovarian masses led to a diagnosis of aggressive B-cell non-Hodgkin lymphoma. The patient was treated with chemotherapy, which achieved complete remission and bilateral ovarian preservation.

If ovarian involvement in malignant lymphoma is suspected, diagnostic methods should spare the ovary and prevent a loss of fertility. To evaluate for possible chemotherapy-induced ovarian damage, including infertility and premature menopause, an interdisciplinary approach is needed for the long-term follow-up of adolescent girls.