Extramedullary early T-cell lymphoblastic crisis in a young pregnant chronic myeloid leukemia patient: Diagnosis with fine-needle aspiration cytology and flow cytometry.

Chronic myeloid leukemia (CML) most commonly presents in chronic phase. Blast crisis in CML is usually of myeloid phenotype, whereas among lymphoid lineage, B-cell lymphoblastic crisis is common. T lymphoblastic crisis is rare with near early T-cell precursor (ETP) immunophenotype being exceedingly rare and very little is known about its characteristics, treatment, and prognosis. Blast crisis can occur in extramedullary sites with lymph node being the most common site. CML is also less investigated and studied in pregnancy as it is considered a disease of older adults. We report a rare case of CML presenting in extramedullary site (lymph node) as extramedullary T-cell lymphoblastic crisis of near ETP immunophenotype in a young pregnant female, which was diagnosed on fine-needle aspiration cytology in combination with flow cytometry.