Pancytopenia Associated with Bone Marrow Infiltration from Late Relapse of Neuroblastoma.

A 30-year-old woman presented to Rhode Island Hospital in October, 2022, with 3 days of fatigue and fevers, and found to be in circulatory shock. 28 years before, she had been treated for high-risk neuroblastoma that had metastasised to the bone treated per the 34-DAT protocol with induction chemotherapy, right adrenalectomy, tandem autologous haematopoietic stem-cell transplants, and total body irradiation and had responded. Laboratory investigation showed pancytopenia (absolute neutrophil count 0 cells per μL, haemoglobin 9·6 g/dL, platelets 17 000 cells per μL) and elevated aspartate aminotransferase (1614 IU/L), ferritin (>16 500 ng/mL), triglycerides (464 mg/dL), fibrinogen (495 mg/dL), and soluble IL-2R (9509·6 pg/mL). A peripheral blood smear showed dacrocytes and nucleated red blood cells. Haemophagocytic syndrome was suspected, and bone marrow biopsy was performed.The bone marrow biopsy was hypercellular (∼90%) and infiltrated by atypical blast-like mononuclear cells (∼80%; figure, A). The aspirate had atypical blast-like cells with irregular nuclear contours, finely reticular chromatin, conspicuous nucleoli, and small amounts of pale basophilic cytoplasm (figure, B). The tumour cells were positive by immunohistochemistry for PHOX2B, synaptophysin, and CD56 and negative for lymphoid and myeloid markers, consistent with metastatic poorly differentiated neuroblastoma with an unfavourable International Neuroblastoma Pathology Classification. Cytogenetic evaluation was negative, including MYCN or ALK amplification. The original tumour specimen was reviewed and showed overall similar features. A MIBG scan showed extensive multifocal heterogeneous uptake throughout the axial and appendicular skeleton. She began treatment with cyclophosphamide (400 mg/m2 intravenously once per day on days 1–5) and topotecan (1·2 mg/m2 intravenously once per day on days 1–5) but died shortly thereafter.