Characteristics of secondary acute lymphoblastic leukemia with L3 morphology in adult patients

Secondary acute lymphoblastic leukemia (sALL) is an uncommon condition and sALL with L3 morphology is still less frequent. Here, we compare the characteristics of available cases of L3 sALL (16 patients, including 12 previously published cases and 4 personal cases) to those of de novo L3 ALL and of non L3 sALL. Two patients with L3 sALL obtained a CR after aggressive treatment of their leukemia. Compared with 24 patients from the literature with de novo L3 ALL, L3 sALL patients were characterized by an older age (median 46 vs. 29.5 years, p = 0.0003) and by a poor prognosis (complete responses: 2/16 vs. 19/24, p = 0.0001, median survival: 0.46 month vs. undetermined, p < 0.0001). In comparison with 19 patients from the literature with non L3 sALL, L3 sALL patients were characterized by a high Male/Female ratio (14/2 vs. 8/11, p = 0.01), a frequent history of Hodgkin's disease (12/16 vs. 7/19, p = 0.04) and, again, by a poor prognosis (complete responses: 2/16 vs. 13/18, p = 0.0001, median survival 0.46 vs. 13 months, p = 0.001). In conclusion, though based on a small group of heterogeneously treated patients, some characteristics of L3 sALL, seem to emerge, compared both with de novo L3 ALL and with non L3 sALL, the most prominent being its extremely poor prognosis.