Primary anaplastic large cell lymphoma of the lung presenting with acute atelectasis

N on‐ H odgkin lymphoma only rarely occurs as a primary lung mass. We report a very rare case of primary pulmonary anaplastic large cell lymphoma presenting with acute atelectasis in a 55‐year‐old man. Chest computed tomography revealed a consolidated central mass in the left lung with obstructive pneumonia that had developed into total atelectasis. After a bronchoscopic examination failed to yield a definite diagnosis, supraclavicular lymph node biopsy was performed, revealing an anaplastic large cell lymphoma. This case illustrates the need for rapidly locating a possible biopsy site, other than the primary lung mass itself, and the value of empirical steroid treatment for avoiding devastating exacerbation when aggressive pulmonary lymphoma is suspected.