Aerogenous Dissemination of DEK::AFF2 Carcinoma : A Prototype of a Previously Underrecognized Pattern of Endobronchial Metastasis From Extrathoracic Malignancies.

In this article, we describe a previously underrecognized pattern of aerogenous dissemination to the lungs, based on 2 cases of sinonasal DEK::AFF2 carcinoma. Over follow-up periods of 10 and 18 years, respectively, both patients exhibited recurrent multiple endotracheal and endobronchial metastases. These lesions were successfully managed with endoscopic tumor resection. No lymph node involvement or distant metastases beyond the trachea and bronchi were observed; they were entirely absent in one case and largely absent in the other. Based on these clinical courses, the tracheobronchial dissemination was most plausibly interpreted as aerogenous rather than lymphatic or hematogenous spread. DEK::AFF2 carcinoma appears to exhibit three key biological features favoring aerogenous dissemination: anatomic location of the primary tumor, loss of intercellular adhesion, and strong affinity for ciliated respiratory epithelium. These cases may help enhance our understanding of aerogenous tumor cell spread, including phenomena such as spread through air spaces (STAS).