To summarize the clinical features of acute lymphoblast leukemia (ALL) with and without nephromegaly at the onset of the disease, and compare the clinical data and prognosis between them.

The clinical data and follow-up results of ALL children who were treated at the Pediatric Hematology and Oncology Ward of Peking University First Hospital from 2010 to 2019 were analyzed retrospectively. The children were divided into either a kidney enlargement group (kidney length ≥ 2 standard deviations from the mean of children of the same age) or a non-kidney enlargement group according to the kidney length measured by ultrasound before treatment at the initial diagnosis.

From 2010 to 2019, 69 patients were primarily diagnosed with ALL and treated at Peking University First Hospital. Their median age was 4 years old. Fourteen (20%) cases had renal enlargement at the onset of the disease, including three cases of unilateral enlargement and eleven cases of bilateral enlargement. Median follow-up time was 112 months. Compared with the non-kidney enlargement group, the age of the children with kidney enlargement was smaller [(79.9±48.0) months vs (37.1±21.9) months, P＜0.05]. There were no significant differences in the gender composition, time from onset to diagnosis, risk stratification, extramedullary invasion, time to morphological complete remission, and event-free survival (EFS) time (P＞0.05). Although there were no statistical differences in creatinine and urea levels between the two groups (P＞0.05), considering the difference in age between the two groups, the renal function of the children with renal enlargement was worse than that of the control group, but the renal function abnormality could recover after treatment. The positive rate of E2A-PbX1 was higher in the children of kidney enlargement group than that of non-kidney enlargement group (28.57% vs 5.36%, P＜0.05).

The proportion of children with renal enlargement at onset is higher than that reported in the previous literature, which suggests that the phenomenon is more common. The age of children with renal enlargement at onset is smaller. With the further optimization of layered treatment, the overall prognosis of children with renal enlargement is the same as that of children without kidney enlargement at the onset. However, we should pay attention to the protection of renal function in the initial treatment.