Tumor-Associated Lymphatic and Venous Vessels in Medullary Thyroid Carcinomas

Objective: Medullary thyroid carcinomas (MTCs) invade local lymph node through lymphatic vessels and metastasize to distant organs hematogenously and account for a significant mortality. There are possibly increased lymphatic and venous vessels, through which the tumor spreads to lymph nodes and distant organs. Materials and Methods: By immunocytochemical staining for lymphatic and venous vessels, MTC lesions with adjacent normal thyroid and both normal and metastatic lymph nodes were studied for the peritumoral lymphatic and venous vessels, which were morphometrically compared with those of normal thyroid and lymph nodes. Sixteen cases of MTC cases with adjacent thyroid tissues and attached lymph nodes were immunocytochemically stained for lymphatic vessels using lymphatic vessel hyaluronan receptor (LYVE-1) and venous vessels for factor VIII (F-8). The immunostained sections of MTC lesions and metastatic lymph nodes were morphometrically compared for the number and sizes of the vessels with those of normal thyroid tissues and lymph nodes. Results: Significantly increased lymphatic vessels and markedly increased blood vessels were identified in many MTC cases at the peritumoral tissues and metastatic lymph nodes whereas a few lymphatic vessels and no venous vessels were identified in midst of MTCs. The irregular peritumoral lymphatic vessels resembled that of immature lymphatic vessels observed in papillary thyroid carcinomas and increased irregularly, entrapped venous vessels in peritumoral tissues resembled those observed in follicular thyroid carcinomas. Conclusion: The significantly increased lymphatic vessels and markedly increased venous vessels in the peritumoral thyroid tissue support a propensity of MTCs for providing an easy access of tumor cells to both lymphatic spread to the regional lymph nodes and venous spread to distant organs with further tumor spread through metastatic lymph nodes by moderately increased lymphatic and venous vessels.

Cancer-Associated Lymphatic and Venous Vessels in Colonic Carcinomas

Objective: Colonic carcinomas spread to regional lymph nodes and liver. There are cancer-associated lymphatic and venous vessels at the margin of colonic carcinomas, which facilitate spreading carcinoma through lymphatic and venous vessels. This study aimed to examine cancer-associated lymphatic and venous vessels in TNM T1 to T3 carcinomas using lymphatic vessel hyaluronan receptor for lymphatic vessels and von Willebrand factor for venous vessels by immunocytochemical staining. Materials and Methods: A total of 40 cases of moderately differentiated colonic carcinoma were studied using routinely formalin-fixed and paraffin-embedded sections. The cases consisted of 10 cases of TNM T1, 15 cases each of T2 and T3 cases. Immunocytochemical staining was performed using goat antihuman LYVE-1for lymphatic vessels and rabbit antihuman von Willebrand factor for venous vessels. Results: In TNM T1 carcinoma, increased, irregular and narrow lymphatic and venous vessels were present in the adjacent normal mucosa to the carcinoma, some of which penetrated cancerous lesion. There were no tumor emboli in lymphatic and venous vessels. In TNM T2 carcinoma, there were few lymphatic and venous vessels in midst of the carcinoma whereas numerous small lymphatic and venous vessels were present within muscle layers adjacent to the invading carcinoma. Extramural tumor embolus was present in submucosa in one case. In TNM T3 carcinoma, cancer has invaded through the muscle layers where dilated lymphatic and venous vessels were present adjacent to cancerous nests. Tumor emboli were identified in two cases by immunocytochemical staining. Conclusion: The current study showed cancer-associated lymphatic and venous vessels at the interface in TNM T1 carcinoma to dilated intramuscular lymphatic and venous vessels adjacent to invading cancerous nests in TNM T3 carcinoma, and supports cancerous cells spread via lymphatic and venous vessels through muscle layers to subserosa as supported by tumor emboli in the lymphovascular system.

人胰腺癌组织LYVE-1表达与癌组织淋巴管转移关系研究

目的观察胰腺癌组织淋巴管内皮细胞LYVE-1的表达,为研究癌淋巴管转移的分子机制提供形态学依据。方法用免疫组化的方法对人胰腺癌和正常胰腺组织中LYVE-1的表达情况进行观察,用LYVE-1来标记淋巴管,检测癌组织中微淋巴管密度(LMVD)。结果胰腺癌组织血管内皮细胞LYVE-1不染色,淋巴管内皮细胞LYVE-1阳性表达,经计数微淋巴管数量,癌组织中的LMVD明显高于癌旁正常胰腺组织(P<0.01),并且LMVD的表达与VEGF-C、VEGF-D的表达具有显著相关性(P<0.01)。结论LYVE-1可选择性的表达在胰腺癌组织淋巴管内皮上,能明确的区分血管及淋巴管成分,可作为一个淋巴管内皮细胞较特异的标记物。由于LMVD在癌组织中的表达明显增高,说明淋巴管数量的增加可能与胰腺癌的淋巴转移有关。