Immunostaining for Factor VIII-related antigen was seen in deparaffinized sections from 19 of 20 postmastectomy angiosarcomas and from four of four sarcomas that arose in chronically edematous tissue unrelated to breast carcinoma. Staining was also seen in sections from two malignant hemangioendotheliomas, four capillary hemangiomas, and one granulation tissue specimen. Sections from two lymphangiomas were immunonegative for Factor VIII-related antigen in the endothelium of lymphatic channels, whereas staining was observed in the surrounding normal blood vessels. Electron microscopic study of four postmastectomy angiosarcomas disclosed ultrastructural features (fenestrae, intense pinocytotic activity, cell junctions, and Weibel-Palade bodies) supporting the blood vascular endothelial nature of the neoplastic cells. It is concluded that a neoplastic blood vessel component is present in sarcomas that arise in chronically edematous tissues. It is questionable whether a lymphatic component is also present. These tumors, therefore, should be regarded as angiosarcomas rather than lymphangiosarcomas.

The World Health Organization Histological Typing of Breast Tumors—Second Edition Get access J. G. Azzopardi, J. G. Azzopardi Search for other works by this author on: Oxford Academic Google Scholar O. F. Chepick, O. F. Chepick Search for other works by this author on: Oxford Academic Google Scholar W. H. Hartmann, W. H. Hartmann Search for other works by this author on: Oxford Academic Google Scholar N. A. Jafarey, N. A. Jafarey Search for other works by this author on: Oxford Academic Google Scholar A. Llombart-Bosch, A. Llombart-Bosch Search for other works by this author on: Oxford Academic Google Scholar L. Ozzello, L. Ozzello Search for other works by this author on: Oxford Academic Google Scholar F. Rilke, F. Rilke Search for other works by this author on: Oxford Academic Google Scholar N. Sasano, N. Sasano Search for other works by this author on: Oxford Academic Google Scholar L. H. Sobin, L. H. Sobin Search for other works by this author on: Oxford Academic Google Scholar S. C. Sommers, S. C. Sommers Search for other works by this author on: Oxford Academic Google Scholar ... Show more H. Stalsberg, H. Stalsberg Search for other works by this author on: Oxford Academic Google Scholar J. Sugar, J. Sugar Search for other works by this author on: Oxford Academic Google Scholar A. O. Williams A. O. Williams Search for other works by this author on: Oxford Academic Google Scholar American Journal of Clinical Pathology, Volume 78, Issue 6, 1 December 1982, Pages 806–816, https://doi.org/10.1093/ajcp/78.6.806 Published: 01 December 1982 Article history Received: 01 March 1982 Accepted: 19 April 1982 Published: 01 December 1982

Specimens from four cases of dermatofibrosarcoma protuberans when explanted in vitro exhibited a typical ameboid outgrowth, confirming the histiocytic nature of these tumors. The cultures displayed the same evolution from macrophages to fibroblast-like cells observed previously in cultures of other types of histiocytomas. Electron microscopic study of the cultures confirmed the light microscopic findings and suggested that the fibroblast-like cells were histiocytes with some secondarily acquired fibroblastic features. The possibility that neoplastic histiocytes may transform into true fibroblasts was deemed unlikely, but could not be excluded.

Electron microscopic study of a granular cell tumor of the urinary bladder revealed myofilaments in the tumor cells, documenting the myogenous derivation of this neoplasm. This is in contrast to the ultrastructural features of the common variety of granular cell tumors, currently interpreted as being indicative of a schwannian histogenesis. The granules of these tumors are similar in ultrastructural appearance regardless of the location of the neoplasms, and are reminiscent of lysosomes and cytosegresomes. It is suggested that granular cell tumors may derive from different cell types.