Hammering home the sickle: an instructive case of endobronchial anaplastic large cell lymphoma.

It is extremely unusual for primary pulmonary lymphoma, an uncommon occurrence in any form, to be of T-cell origin and to manifest as an endobronchial lesion. Each of these characteristics is rare individually, so cases that combine them are exceptional. We report a patient in whom primary pulmonary anaplastic large cell lymphoma, a T-cell neoplasm, presented with obstruction of the left upper lobe bronchus, resulting in left upper lobe atelectasis and creating the radiographic luftsichel sign. We briefly discuss anaplastic large cell lymphoma as a whole, place our case in the context of previously published literature on endobronchial anaplastic large cell lymphoma, and review the genesis of the luftsichel sign.