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Unusual ovarian leukemic relapse in a girl with history of B‐cell lymphoblastic leukemia

To the Editor: Extramedullary leukemic recurrence mostly occurs in the central nervous system and occasionally in the skin.1 Here, we report an unusual case of a girl with relapsed lymphoblastic leukemia involving the ovary, presenting as a large pelvic mass. A 10-year-old girl with a history of B-cell lymphoblastic leukemia treatment, who had gone into remission 1 year prior, presented to an oncology clinic with a painless palpable pelvic mass that had been enlarging for 2 months. Magnetic resonance imaging revealed a large lobulated solid heterogeneous pelvic mass (measuring 12 cm in the greatest dimension) with mass effect on pelvic organs (Figure 1A). Bone marrow aspirate at the conventional site confirmed the absence of lymphoblastic cells, which would have suggested leukemia relapse. In view of the suspicion of a second primary tumor in the ovary with complications, exploratory laparotomy and left salpingo-oophorectomy were performed (Figure 1B). Histology showed diffuse infiltration of the ovary by B-cell lymphoblastic leukemia. Hematoxylin and eosin staining showed sheets of lymphoid cells with irregular nuclei. The tumor cells were positive for TdT, CD19, CD79a, and CD34 (Figure 1C). She was well after the operation. In view of extramedullary relapse, bone marrow aspirate was repeated after operation at the anterior iliac spine, which confirmed bone marrow relapse. She received treatment according to the high-risk protocol of Chinese Children’s Cancer Group (CCCG) Relapsed Acute Lymphoblastic Leukemia 2017 Study in Children.2 Acute lymphoblastic leukemia (ALL) is responsible for one-third of childhood malignancy. Despite efforts in the treatment of ALL, 15%– 20% of patients relapse, with the risk being highest immediately after cessation of treatment and diminishing with time.3 Extramedullary involvement constitutes 2%–5%of all relapses, with themajority in the central nervous system. It seldom involves other sites, such as the eye, kidney, and omentum. Ovarian leukemic relapse is rarely reported in children with scarce case reports in the literature.4,5 It is insidious and not usually detected until symptoms arise. The patientmost commonly presents with lower abdominal pain or a palpable large abdominal mass.6 Timely detection is important as it often coincides withmarrow recurrence and increased future risk of other extramedullary recurrence. Pelvic sonography is advocated as a routine surveillance tool for timely detection of pelvic extramedullary relapse. Its diagnostic yield is low, given rarity of ovarian recurrence. However, it would be particularly useful in symptomatic patients.1,7 In patients with a background of leukemia presenting with an ovarian mass, a higher level of suspicion is needed. In the absence of evidence of bone marrow relapse at the conventional site, repeat marrow aspirate at another site would be warranted, as this affects the choice of management. Previous reports have shown that chemotherapy had a beneficial effect, while neither local radiation nor extensive surgical resection of the leukemic mass had any obvious effect on overall outcome.8 An operation could have been avoided if marrow relapse was confirmed at the time of ovarian mass detection. However, surgical excision is reported to have a role in situation when bone marrow had a good response but no signs of regression of ovarianmass.9