Primary diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma (NHL) globally, while primary mediastinal B-cell lymphoma (PMBCL) is a rare subtype that may lead to central airway obstruction by compressing or invading the airways. Prompt management of airway obstruction is crucial, as severe cases can be life-threatening if left untreated. This study reports the case of a 27-year-old man with chronic cough, weight loss, and computed tomography (CT) of the chest revealing a large anterior mediastinal tumor with an extension into the neck and left lung causing airway compression and complete left lung collapse who was found to have PMBCL. The aim of this case report is to show that, in some cases of malignant central airway obstruction, the treatment approach should be based primarily on treating the underlying cause instead of procedural intervention, depending on clinical presentation and history of response to therapy. We highlight the treatment strategy of primary therapy for DLBCL to address central airway obstruction rather than surgical or bronchoscopic intervention.