A previously healthy man of 18 years presented a 2-week history of progressive headache and weakness. The physical examination showed purpuric skin lesions on the skin of the thorax, bilateral cervical and inguinal lymphadenopathies and hepatosplenomegaly.
A complete blood count test showed a hemoglobin concentration of 78 g/l, a platelet count of 36 x 109 / L and a leukocyte count of 3.9 x 109 / L with 62% of blast cells. A bone marrow aspirate showed 89% blasts of undifferentiated morphology, with positivity with periodic acid-Schiff       (PAS) but negativity with myeloperoxidase and alpha-naphthyl acetate esterase. Flow cytometry (positive for CD4, CD45A, CD56, CD123 and HLA-DR) revealed the rare diagnostic plasmocytoid plastic dendritic cell neoplasm. Cerebrospinal fluid (CSF) samples showed> 90% tumor cells
The patient was treated with a regimen of acute lymphoblastic leukemia (ALL) and triple intrathecal therapy (TIT). This treatment regimen achieved complete remission (CR), but the patient developed an early and isolated relapse in the CNS. Currently, the patient is waiting to receive an allogeneic hematopoietic stem cell transplant (AHSCT).