Leukemic phase of hepatosplenic T-cell lymphoma Free

A 25-year-old, previously healthy woman, presented with nausea, vomiting, abdominal pain, and a worsening facial rash over 2 weeks. Abnormal laboratory findings included hyperleukocytosis (133 × 10⁹/L), anemia, and thrombocytopenia; elevated liver enzymes, lactate dehydrogenase (3478 U/L), uric acid (7.8 mg/dL), and potassium (5.8 mmol/L); and hyperphosphatemia and hypocalcemia. Epstein-Barr virus serology tests were negative. Computed tomography scans demonstrated marked hepatosplenomegaly and no lymphadenopathy. The patient fulfilled the criteria for tumor lysis syndrome from presumed acute leukemia and was started on allopurinol. The peripheral blood smear showed numerous pleomorphic, large-sized, blastoid cells (65% of white blood cells) with fine chromatin, prominent nucleoli, and abundant, agranular blue cytoplasm (panel A; Wright-Giemsa stain; 50× objective, oil). Flow cytometry characterized this population as mature γδ T cells (CD3⁺/CD5^–/CD2⁺/CD7⁺/CD16⁺/CD56⁺/CD8dim⁺/TCRγδ⁺/CD4^–/TCRαβ^–/CD1a^–/CD10^–/CD34^–/CD117^–/TdT^–) (panel B; select flow cytometry plots with abnormal population indicated in blue; normal residual T cells indicated in green). Chromosome banding analysis revealed an abnormal clone, 46,X,–X,i(7)(q10),+8[3]/46,XX[17] with isochromosome 7q and trisomy 8 (panel C; red and blue box outlines, respectively), in addition to loss of X. Based on the overall clinicopathologic findings, the patient was diagnosed with leukemic phase of hepatosplenic T-cell lymphoma (HSTCL) and was started on ICE (ifosfamide, carboplatin, etoposide) induction chemotherapy.

Overt leukemic phase with concomitant spontaneous tumor lysis syndrome and blastoid morphology is particularly rare in HSTCL on initial presentation before treatment.

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