Diagnostic difficulties caused by a pulmonary infiltrate]

Lung infiltration still causes differential diagnostic difficulties, which may delay the start of definitive treatment.The examination of a 30-year-old man began due intermittent, remittent and permanent fever. Chest X-ray confirmed infiltration in the right upper lobe, which was accompanied by elevated CRP and physiological levels of procalcitonin. Most likely atypical pneumonia, tuberculosis, Wegener's granulomatosis or a malignant process was suspected. Throughout his examination infection could not be verified, repeated CT guided transthoracic needle biopsy suggested the possibility of a malignant process. Through surgical exploration the intraoperative histology was not informative; thus, the pneumonitis-remodelled right lung was removed due to the possibility of malignant transformation. Histological examination revealed lymphocyte rich classical Hodgkin lymphoma, which was found to be stage IV/B based on the 18FDG-PET/CT scan; therefore, eight cycles of ABVD (adriablastin, bleomycin, vinblastine, and dacarbazine) therapy was administered successfully. The patient is currently (for 30 months) in a complete metabolic remission.Primary pulmonary Hodgkin lymphoma is a rare disease entity (in this case it might be the original process), in which the diagnosis is often difficult. 18FDG-PET/CT may be a useful early diagnostic tool investigating fever of unknown origin.