Organizing Pneumonia: A Clinical Challenge in a Child With Previous Rhabdomyosarcoma.

Organizing pneumonia is a pulmonary disease of undefined etiology, with few reported cases in children. It may be secondary to chemotherapy, radiation therapy, infectious agents, or hematopoietic cell transplantation. We present a case of an 18-year-old boy who presented to a follow-up consult with respiratory symptoms at the age of 11 years, 8 years after finishing treatment for a prostatic relapse of a pelvic rhabdomyosarcoma. Chest radiography revealed nodular opacities in the left lung, the one in the left lower lobe with silhouette sign with the left hemidiaphragm. Chest computerized tomography showed 2 nodular lesions in the left upper lobe, one of them cavitated, and another nodular lesion in the left lower lobe; 2 of these nodules had surrounding ground-glass opacities. Microbiological work-up, including tuberculosis screening, was negative. Biopsy revealed findings suggestive of organizing pneumonia. He presented spontaneous resolution. This case presented a diagnostic challenge due to rarity of this condition and its indetermined association with the patient's history of rhabdomyosarcoma. With this case, the authors alert that organizing pneumonia must be considered in patients presenting with pulmonary lesions with a history of previous hematopoietic stem cell transplants, lung irradiation, or immunosuppression. Pulmonary metastases and secondary tumors must be considered as a differential diagnosis in patients with a heavily treated relapsed rhabdomyosarcoma.