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A female neonate was delivered at 38 weeks of gestation by emergency caesarean section due to non-reassuring fetal status with polyhydramnios (amniotic fluid index: 39 cm) and fetal hepatomegaly. She presented with hypotonia and poor respiratory effort at birth, requiring intubation and resuscitation. Persistent pulmonary hypertension was diagnosed and treated with 100% oxygen and inhaled nitric oxide. Numerous dark-purple papular to nodular lesions (1–10 mm) were noted on the face, trunk and extremities, covering nearly the entire body ( figure 1). Hepatosplenomegaly was also evident. Laboratory findings included extreme hyperleukocytosis with a leucocyte count of 535.7 × 109/L, anaemia (haemoglobin 7.2 g/dL), a normal platelet count (186 × 109/L), elevated lactate dehydrogenase (7829 IU/L), and hyperuricaemia (uric acid 7.3 mg/dL). Exchange transfusions were performed four times to reduce leukocytosis-related hyperviscosity and manage tumour lysis syndrome. Bone marrow examination showed a predominance of immature monocytic cells, consistent with acute monocytic leukaemia (AML), classified as M5 by the French-American-British criteria. A KMT2A::ELL fusion transcript was detected. Chemotherapy with low-dose cytarabine (8.0 mg/day) was initiated on day 4, followed by etoposide (5.0 mg/day) on day 8. All skin lesions resolved in parallel with a marked decline in leucocyte count: 3.8 × 109/L on day 7 and 0.1 × 109/μL on day 14. Although she developed a cerebellar parenchymal haemorrhage, likely secondary to hyperviscosity, the patient achieved haematological remission and remains on continued intensive chemotherapy at 4 months of age.