Filgrastim-Associated Pneumonitis in Cancer Patient Undergoing Hematopoietic Stem Cell (HSC) Mobilization for Autologous-HSC Transplantation.

Filgrastim is a granulocyte-colony stimulating factors (G-CSF) used for multiple indications in cancer patients. We present a case of a 65-year-old man with non-Hodgkin's lymphoma who was undergoing mobilization of hemopoietic stem cells for autologous-hematopoietic stem cell transplantation (auto-HSCT) with filgrastim who developed dyspnea and non-productive cough. Chest imaging showed left lower lobe consolidation, new ground-glass opacities and small right-sided pleural effusion. Bronchoscopy with bronchoalveolar lavage (BAL) and infectious evaluation were completely negative. He was admitted for further evaluation and management. Antibiotics weren't started immediately given the clinical stability, multiple probable causes of fever and the intent of not confounding future thoracentesis results with antibiotic use. Thoracentesis occurred draining serous exudative pleural fluid; with follow-up chest imaging demonstrating no re-accumulation. His symptoms resolved and he was discharged in stable condition. The symptoms were hypothesized to be the probable adverse effects of filgrastim. We suggest close monitoring of pulmonary toxicities while administering this drug to patients to minimize such complications.