论文部分内容阅读
Background Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts is a rare soft tissue tumor,which isgenerally considered low-grade.To distinguish the tumor from other soft tissue lesions,we analyzed the clinicopathologicand ultrastructural features,immunophenotypes,and flow cytometric DNA ploidy of PHAT in 9 cases.Methods PHAT specimens were collected from 9 patients with PHAT from 1990 to 2004.Each specimen was cut intopieces and stained with hematoxylin-eosin,phosphotungstic acid-hematoxylin,Prussian blue,and Masson trichrome,respectively.Immunohistochemical stains for vimentin,S-100 protein,0D34,0D31,0D99,VEGF,desmin,CD_(117),a-SMA,and MIB-1 were performed with the Envision system.Flow cytometry was used in four specimens,two of which wereobserved by electron microscopy.Results In the 9 cases,the PHAT occurred at the lower extremity in 2 patients,inguinal in 2,waist in 1,forearm in 1,buttock in 1,foot in 1,and the chest wall in 1.All the lesions presented in the superficial subcutaneous tissues.Follow-updata were available in 7 of the patients,among whom 2 (28.6%) had recurrence after primary therapy.Microscopically,typical PHAT was characterized by sheet-like proliferation of spindle or pleomorphic cells and clusters of thin-walledhyalinized cstatic vessels.In some areas of the tumor,hemosiderin-laden spindle cells,numerous small single vessels,and myxoid extracellular matrix could be identified,indicating an “atypical PHAT”.Mitotic figures were rare in all the casesIn 5 of the 9 patients (55.6%),the tumor was typical PHAT;and in the other 4 (44.4%),typical and atypical PHATcoexisted.Immunohistochemically,the neoplastic cells were positive for vimentin,CD34,0099,and VEGF,but negativefor S-100 protein,desmin,SMA,and CD_(31).In all the cases,the MIB-1 proliferative activity of the neoplastic cells waslower than 2%.Ultrastructural analysis did not reveal any evidence of specific differentiation.Aneuploidy was notdetected by flow cytometry.Conclusions Histologically,typical PHAT is characterized by spindle and pleomorphic cells associated with anangiectatic vasculature.The neoplastic cells often express vimentin and 0934,and may be positive for 0099 and VEGF.Ultrastructurally,the tumor usually has no specific differentiation.The low MIB-1 index and the absence of aneuploidy inPHAT indicate a non-malignancy.However,we consider the tumor as a borderline neoplasm because of its aggressivebehaviour,and suggest wide local resection with tumor-free margin for the treatment of the disease.
Background Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts is a rare soft tissue tumor, which isgenerally considered low-grade. To distinguish the tumor from other soft tissue lesions, we analyzed the clinicopathologic and ultrastructural features, immunophenotypes, and flow cytometric DNA ploidy of PHAT in 9 cases. Methods PHAT specimens were collected from 9 patients with PHAT from 1990 to 2004. Each specimens was cut in topieces and stained with hematoxylin-eosin, phosphotungstic acid-hematoxylin, Prussian blue, and Masson trichrome, respectively. Immunohistochemical stains for vimentin , S-100 protein, 0D34,0D31,0D99, VEGF, desmin, CD 117, a-SMA, and MIB-1 were performed with the Envision system. Flow cytometry was used in four specimens, two of which wereobserved by electron microscopy.Results In the 9 cases, the PHAT occurred at the lower extremity in 2 patients, inguinal in 2, waist in 1, forearm in 1, buttock in 1, foot in 1, and the chest wall in 1.All the lesions presented in the superficia l subcutaneous tissues. Frolow-updata were available in 7 of the patients, among whom 2 (28.6%) had recurrence after primary therapy. Microscopically, typical PHAT was characterized by sheet-like proliferation of spindle or pleomorphic cells and clusters of thin-walled hyalinized cstatic vessels .In some areas of the tumor, hemosiderin-laden spindle cells, numerous small single vessels, and myxoid extracellular matrix could be identified, indicating an “atypical PHAT ”. Mitotic figures were rare in all the casesIn 5 of the 9 The tumor was typical PHAT; and in the other 4 (44.4%), typical and atypical PHATcoexisted. Immunohistochemically, the neoplastic cells were positive for vimentin, CD34, 0099, and VEGF, but negative for S-100 protein All in the cases, the MIB-1 proliferative activity of the neoplastic cells was lower than 2%. Ultrstructural analysis did not reveal any evidence of specific differentiation. Aneuploidy was not detected by flow cytometry. Conclusions Histologically, typical PHAT is characterized by spindle and pleomorphic cells associated with anangiectatic vasculature. The neoplastic cells often express vimentin and 0934, and may be positive for 0099 and VEGF. Ultratrastructurally, the tumor usually has no specific differentiation. The low MIB-1 index and the absence of aneuploidy in PHAT a non-malignancy. However, we consider the tumor as a borderline neoplasm because of its aggressive behavior, and suggest wide local resection with tumor-free margin for the treatment of the disease.