Do adrenal metastases from lung cancer develop by lymphogenous or hematogenous route?

In order to analyse the possible mode and pathways of adrenal metastases from lung cancer, the frequency of adrenal metastases ipsilateral and contralateral to the site of the primary cancer was investigated based on autopsied lung cancer cases. In 405 of 1,607 such cases, adrenal metastases could be found: on both sides, 234; ipsilateral only, 105; contralateral only, 66 cases. In the early stages of tumor progression, a striking difference can be seen between the two sides. Ipsilateral metastases were of significantly higher incidence in early metastatic tumor stages, but later, in cases having six or more involved organs, the ipsilateral/contralateral quotient reaches 1. It is postulated that in the early stages adrenal metastases from lung cancer probably develop mainly by lymphogenous, but later mainly by hematogenous routes.