Lymphovascular invasion: assessment and prognostic impact in melanoma and breast cancer

The presence of lymphovascular invasion is a recognised poor prognostic factor in a wide range of tumour types. Vascular invasion was historically identified through haematoxylin and eosin staining, however this technique is non-specific and differentiates poorly between blood and lymphatic vessels. Newer techniques using immunohistochemistry allow more sensitive and specific identification of lymphovascular invasion and are able to accurately differentiate between lymphatic and blood vessels. This review will discuss the current methods available for the assessment of lymphovascular invasion. Additionally, it will focus on the role of lymphovascular invasion in breast cancer and melanoma, discussing the relative importance of lymphatic and blood vessel invasion in each tumour type.