Angiosarcoma (AS) is a malignant tumor of endothelial cells.
AS of the urogenital tract is very rare, with most studies consisting of single case reports. A weak association with previous radiotherapy has been reported.
It occurs in adult and elderly patients.
AS of the kidney occurs more frequently in males than females (M:F = 7:1).
Urogenital angiosarcomas arise more frequently in the kidney and prostate. Rare cases have been described in the ureter, the bladder, the epididymis, and the penis.
Surgery is the primary treatment, with radiotherapy and chemotherapy employed in approximately 30% of the patients.
AS is a high-grade tumor with frequent local relapse and lymph node and distant metastases. The lungs and liver are the most common sites of metastasis.
Grossly, the tumor presents as an ill-defined, invasive hemorrhagic mass often with areas of necrosis. AS are often large lesions ranging from 3 to 30 cm in maximum dimension.
AS is positive for endothelial cell markers, including CD34, CD31, ERG, FLI1, and factor VIII-related antigen. The lymphatic endothelial marker podoplanin may also be expressed. Epithelioid AS is frequently immunoreactive for cytokeratins.
Molecular studies have not been conducted so far on urogenital AS. In general, AS presents distinct upregulation of vascular-specific receptor tyrosine kinases and mutations of genes involved in the control of angiogenesis.
Well-differentiated AS may be difficult to distinguish from anastomosing hemangioma. This benign vascular tumor is composed of anastomosing capillary-sized vessels lined by cytologically bland endothelial cells with hobnail appearance. The complex architecture may resemble that of AS, but it lacks atypical features, including nuclear hyperchromasia, multilayering, atypical mitotic figures, and necrosis.
Poorly differentiated angiosarcomas with solid architecture must be distinguished from other high-grade sarcomas, from sarcomatoid carcinomas and melanoma. Kaposi sarcoma can be excluded based on the absence of HHV8 immunoreactivity.
References and Further Reading
- Brown, J. G., Folpe, A. L., Rao, P., Lazar, A. J., Paner, G. P., Gupta, R., Parakh, R., Cheville, J. C., & Amin, M. B. (2010). Primary vascular tumors and tumor-like lesions of the kidney: A clinicopathologic analysis of 25 cases. The American Journal of Surgical Pathology, 34, 942–949.CrossRefGoogle Scholar
- Gogoi, D., Hazra, S., Ghosh, B., & Pal, D. (2013). Angiosarcoma of penis. BML Case Reports, 2013. pii: bcr2013200878.Google Scholar
- Seethala, R. R., Gomez, J. A., & Vakar-Lopez, F. (2006). Primary angiosarcoma of the bladder. Archives of Pathology & Laboratory Medicine, 130, 1543–1547.Google Scholar