Transformation of CMML to AML presenting with acute kidney injury.

Characterized by bone marrow dysplasia and peripheral blood monocytosis, chronic myelomonocytic leukemia (CMML) is one of the most aggressive chronic leukemias and has a propensity for progression to acute myeloid leukemia (AML). Patients with newly diagnosed AML generally present with symptoms related to complications of pancytopenia but can also present with renal insufficiency. We present a 79-year-old male with a past medical history of CMML and chronic kidney disease stage 3 (baseline creatinine 1.8 mg/dL) who presented with one day of inability to urinate and 20-lb unintentional weight loss, fatigue, and bone pain over 3 months. Laboratory evaluation revealed leukocytosis of 88.5 x 103/uL (normal 4.8-10.8 x 103/uL) with 24.0% monocytes on differential, creatinine 2.94 mg/dL (baseline creatinine 1.7-1.9 mg/dL), uric acid 19.8 mg/dL, potassium 4.0 mmol/L, phosphorus 4.0 mg/dL, calcium 9.2 mg/dL, and albumin 3.2 g/dL. Urinalysis was significant for protein 200 mg/dL, 20/LPF granular casts, and 7/LPF hyaline casts. Bone marrow biopsy revealed 20-30% blasts with monocytic features of differentiation consistent with acute myeloid leukemia. Computed tomography (CT) of the abdomen and pelvis appreciated splenomegaly with retroperitoneal, and pelvic lymphadenopathy. Kidney failure can complicate the presentation of AML but can be rapidly reversible with treatment. In patients with CMML who have progressive renal insufficiency and hyperuricemia, there should be a high index of suspicion for progression to AML.