Angiomatosis of Soft Tissue An Analysis of the Histologic Features and Clinical Outcome in 51 Cases

The clinicopathologic features and clinical behavior of 51 cases of angiomatosis of soft tissue are analyzed. We have defined this lesion as a histologically benign vascular lesion that affects a large segment of the body in a contiguous fashion either by vertically involving multiple tissue types (e.g., subcutis, muscle, bone) or by involving similar tissue types (e.g., multiple muscles). Such lesions usually present in the first two decades of life and have a highly characteristic but not totally specific histologic pattern. The common pattern consists of a haphazard proliferation of vessels of varying sizes, particularly large veins. The latter have irregularly attenuated walls and intimal redundancies. However, the most distinctive feature is the presence of clusters of capillary vessels residing within or just adjacent to the vein walls. A second but uncommon pattern is that of clusters of capillary-sized vessels infiltrating the soft tissues. Both types are typically associated with large amounts of fat, suggesting that these lesions are more generalized mesenchymal proliferations rather than exclusive vascular lesions. This idea is supported by one unique case that included as part of the lesion a diffuse proliferation of glomus cells. Follow-up information in 25 cases (median 5 years; range 1-24) indicated that 22 patients experienced local recurrences. Nine patients developed more than one recurrence. There was no correlation between the age of onset of the lesion and the number of recurrences. Based on this follow-up information and the fact that no patient showed histologic progression of the lesion with time to angiosarcoma, surgical therapy should be conservative and aimed at balancing the need to cure the patient at the first operation with the ensuing morbidity.