[Effective therapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone chemotherapy with obinutuzumab for follicular lymphoma in leukemic phase].

The patient, a 56-year-old lady, also exhibited numerous lymphadenopathy, hepatosplenomegaly, hyperleukocytosis (167,200/µl, aberrant lymphocytes 91.5%), and fever. A lymph node biopsy revealed follicular lymphoma (FL), grade 1. Peripheral blood tumor cells did not express CD10, which was a distinctive characteristic of the lymph node specimen. To prevent tumor lysis syndrome (TLI), CHOP was delivered without an anti-CD20 antibody, but afterward, residual lymphoma cells were found in peripheral blood (>80%). As a result, obinutuzumab (Obi) was given on day 8 following the second round of CHOP, and the tumor cells in the peripheral blood vanished without any major side effects like TLI. She underwent six chemotherapy sessions before receiving maintenance therapy with Obi and achieving a full metabolic response. According to reports, leukemic FL exhibits negative CD10 expression in peripheral blood lymphoma cells, while leukemic mantle cell lymphoma also shows this trait. Therefore, it is important not to confuse the two types in diagnosis. Leukemic FL with significant leukocytosis is reportedly uncommon and has a bad prognosis. Our case indicates that CHOP with Obi would be a good alternative for cases like yours, however, there have been a few cases recorded. Further case accumulation or investigation is warranted.