Abstract
A 1-year-6-month-old girl came to our hospital with complaints of multiple subcutaneous tumors in such areas as the forehead, temporo-occipital region, and lower gingiva. She had hepatomegaly, 5 cm at MCL, but no anemia, jaundice, bleeding tendency and lymphadenopathy. Her WBC count was 11, 900/μl with no blasts. Her RBC count was 530×104/μl, Hb. 13.2 g/dl, PLT. 37.1 × 104/μl. The LDH level was 386 IU/l with slight elevation. On CT examination, the forehead tumor extendingly expanded into the intracranial mass with positive Ga scintigraphy. Biopsy of the tumor and the bone marrow confirmed the diagnosis of ALL, L-2 type by FAB classification. The surface markers of the blasts were CALLA (+), CD-20 (+), B-4 (+), T-1 (+), T-11 (+), suggesting T/B hybrid leukemia. HL-3 protocol therapy was begun and her response was good. Since her leukemic cells had double markers, T- and B-cell markers, further careful follow-up and therapy are necessary. ALL with initial tumor formation is a very rare type of leukemia, so we have to take special care in the diagnosis of the leukemia to avoid overlooking this possibility.
