In the peripheral arterial chapter 1, primary vascular tumors were described with an emphasis on the lesions that affect arteries and capillaries. The goal of this chapter is to expand upon that chapter to include peripheral tumors of venous and lymphatic origin. It is well known that the classification of peripheral vascular tumors is very difficult and that the schemes have changed over time. These schemes have been based on a wide variety of characteristics, including morphologic criteria and clinical behavior. Classification challenges include both determining if a lesion is a tumor (hemangioma) or a vascular malformation (hamartoma) and further in determining if a tumor is benign or malignant. To further complicate the matter, many lesions contain both arterial and venous elements. We have attempted to include tumors with primarily venous components or those that arise in a vein. Because of this overlap, some of these lesions were already described in the arterial chapter 1 and are not discussed here. In this chapter, lesions are classified by the criteria of Calonje and Fletcher,1 which take into account both pathologic appearance and clinical behavior.
Clinical Features. Intravascular papillary endothelial hyperplasia is a benign lesion that is believed to arise as an unusual form of organizing thrombus (Figure 39-1). It was first described by Masson in 19232 as a "vegetant intravascular hemangioendothelioma," which he found in a thrombosed hemorrhoidal vein and can be mistaken for a host of other vascular lesions, including angiosarcoma. Masson believed he had found a benign neoplastic lesion; however, in 1932, Henschen3 identified a similar vascular growth which he believed was a reactive process. The tumor was then renamed intravascular capillary endothelial hyperplasia in 1976 by Enzinger and Clearkin.4
Intravascular papillary endothelial hyperplasia (Masson's tumor) showing the characteristic small delicate papillary projections lined by flat endothelium growing intraluminally within a large vessel. Part of the vessel is seen at the lower part of the image.
Masson's tumor has no gender predilection and can occur at many different locations, including the head, neck, trunk, and fingers. Early studies showed no age predilection, but more recent analysis shows frequent occurrences in young adults.1 The tumor commonly appears as an asymptomatic nodule that is sharply demarcated and slightly raised over the surrounding skin. Rare case reports have described origins in the renal vein5,6,7,8,9 Although the literature indicates that this tumor was initially considered solely an intravascular lesion, a more recent analysis10 identified three variations in presentation, which are (1) primary-pure form located inside an isolated blood vessel; (2) secondary formation inside a preexisting vascular lesion such as a hemangioma, and (3) extravascular (very rare). Masson's tumor tends to be small ...