Isolated trisomy 10 in an infant with acute myeloid leukemia: a case report and review of literature.

Trisomy 10 as the sole cytogenetic abnormality in AML is rare, with an incidence rate of < 0.5%. It tends to affect the elderly and is extremely rare in pediatric patients. We describe a case of an 8-month-old Caucasian baby who presented with prominence of left eye and fever without lymphadenopathy or hepatosplenomegaly. Bone survey showed diffuse periosteal reaction in the femur, pelvis, maxillary and orbital bones (with fracture). CBC revealed normal white blood cell count with increased blasts, mild anemia and moderate thrombocytopenia. Bone marrow biopsy showed increased myeloblasts with bilineage dysplasia and 3-4+ reticulin fibrosis. Flow cytometry revealed blasts positive for CD34, CD33, and MPO and negative for CD7, CD13, and HLA-DR. Trisomy 10 was demonstrated by chromosome analysis and fluorescence in-situ hybridization. The patient received induction chemotherapy and achieved complete clinical and hematologic remission at day 28. However, he relapsed after three cycles of chemotherapy. Compared to the two other reported pediatric cases, our patient has some unique features such as much younger age and additional findings such as bilineage dysplasia and bone marrow fibrosis. Both reported cases and our case were classified as AML-M2 indicating that this may be a common subtype in pediatric patients. Bone involvement was present in our patient and one other case and both had similar immunophenotype (CD33+, CD7-). These findings suggest that isolated trisomy 10 may be associated with distinct clinicopathologic features in pediatric AML. Studies on additional patients are needed to establish this association.