PLC results from hematogenous spread to lung, with subsequent interstitial and lymphatic invasion, or, as in this case, direct lymphatic spread of tumor from hilar or mediastinal lymph nodes.

• 再次谢谢马哥！）PLC可由血道转移，随后是间质浸润、淋巴道转移，或如此例直接由肺门或纵隔淋巴结的转移癌蔓延而来。