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

• PLC可由血道转移、间质浸润、淋巴道转移，或如此例由肺门或纵隔淋巴结、肿瘤直接蔓延而来。