Spontaneous subcapsular splenic hematoma associated with filgrastim in a patient undergoing allogeneic hematopoietic stem cell transplantation.

OBJECTIVE: To report the development of a spontaneous subcapsular splenic hematoma following filgrastim administration in a patient undergoing an allogeneic hematopoietic stem cell transplant.

CASE SUMMARY: A 60-year-old female with myelodysplastic syndrome was admitted for a reduced-intensity allogeneic hematopoietic stem cell transplant from an unrelated donor. She received filgrastim 5 μg/kg starting on day 1 to accelerate neutrophil recovery. On day 5, she began reporting severe left chest-wall pain. Contrast-enhanced computed tomography of the abdomen/pelvis revealed a spontaneous subcapsular splenic hematoma. Upon discontinuation of filgrastim, the pain fully resolved. The patient was subsequently rechallenged with filgrastim, which led to recurrence of the left-sided chest-wall pain. Filgrastim was discontinued and the patient reported resolution of the pain.

DISCUSSION: Filgrastim has been associated with splenic hematoma and splenic rupture, predominantly in healthy donors undergoing mobilization of peripheral blood stem cells. Although splenic rupture attributed to filgrastim in a patient undergoing allogeneic hematopoietic stem cell transplantation has been reported, to our knowledge, this is the first case report to establish causality. Using the Naranjo probability scale, an objective causality assessment revealed that the adverse drug event was highly probable.

CONCLUSIONS: Although filgrastim-induced splenomegaly, splenic hematomas, and splenic rupture are rare, clinicians working in the bone marrow transplant setting should be cognizant of the potential of growth factors to cause these adverse events.