Bonghan Ducts as Possible Pathways for Cancer Metastasis

ObjectiveThe present study has been designed to find a possible new route for the metastasis of cancer cells on the fascia surrounding tumor tissue using a novel technique of trypan blue staining.Materials and MethodsTumor tissues were grown in the skin of nude mice after sub-cutaneous inoculation with human lung cancer cells. Trypan blue was recently identified as a dye with specificity for Bonghan ducts (BHDs) and not other tissues, such as blood or lymph vessels or nerves.ResultsWe demonstrate that the trypan blue staining technique allows the first visualization of BHDs which are connected to tumor tissues.ConclusionSince BHDs are known to make up a circulatory system corresponding to acu puncture meridians or collaterals, we propose that, in addition to the currently known blood or lymph vessels, BHDs on tumor tissue fascia may be a novel pathway for metastasis.