Collision tumor of pulmonary adenocarcinoma and small lymphocytic lymphoma: A rare case of concurrent malignancies in the same lymph node.

Background: Collision tumors, a rare and challenging diagnostic entity, are characterized by the simultaneous presence of two distinct histological neoplasms within the same anatomical site. The underlying mechanisms of collision tumors are not well understood, though various theories attempt to explain this phenomenon.

Case Presentation: A 77-year-old Palestinian man, a heavy smoker with multiple comorbidities, presented with a productive cough and significant weight loss.