Myofibroblastic sarcomas： a clinicopathological study of 20 cases

• Published in: Chinese medical journal Vol. 120; no. 5; pp. 363 - 369
• Main Authors: Meng, Guo-zhao, Zhang, Hong-ying, Bu, Hong, Zhang, Xian-liang, Pang, Zong-guo, Ke, Qi, Liu, Xi, Yang, Guo
• Format: Journal Article
• Language: English
• Published: China Department of Pathology and Laboratory of Pathology, West China Hospital, Sichuan University, Chengdu 610041,China%Department of Electron Microscopy, School of Preclinical and Forensic Medicine, Sichuan University, Chengdu 610041,China 05-03-2007
• Subjects: Adolescent; Adult; Child; Desmin - analysis; Female; Fibrosarcoma - chemistry; Fibrosarcoma - pathology; Humans; Immunohistochemistry; Male; Middle Aged; Myosarcoma - chemistry; Myosarcoma - pathology; Recurrence; Soft Tissue Neoplasms - chemistry; Soft Tissue Neoplasms - pathology; 临床病理学; 成肌纤维细胞肉瘤; 细胞质; myofibrosarcom; sarcoma; immunohistochemistry; myofibroblast
• ISSN: 0366-6999; 2542-5641
• DOI: 10.1097/00029330-200703010-00003

Background Myofibroblastic sarcoma was used to be a controversial neoplasm. This study investigated the clinicopathological features of 20 cases of myofibroblastic sarcoma arising in different locations. Methods The paraffin-embedded tissue samples from 20 cases of patients with myofibroblastic sarcoma were stained immunohistochemically, and 5 cases examined by electron microscopy. Student＇s t test was used to analyze the difference of Ki-67 labeling index between grade 1 and grade 2 myofibroblastic sarcomas. Results Histologically, the tumors were composed of slender spindle cells with eosinophilic cytoplasm, and fusiform, tapering, wavy, or plump ovoid; vesicular nuclei and a small central eosinophUic nucleoli. Immunohistochemically, the tumor cells expressed smooth muscle actin （18/20）, muscle specific actin （16/20）, fibronectin （20/20） and desmin （2/20）. Ultrastructurally, the tumor cells revealed abundant rough endoplasmic reticulum and longitudinally arranged fine filaments with focal densities in the cytoplasm. A clinical follow-up of 19 patients showed that 2 cases experienced local recurrence and distant metastasis 6 months to 4 years after the initial operation. Nine cases recurred locally 17 to 46 months after the initial excision, and 9 cases were alive with no evidence of disease. Conclusions Myofibroblastic sarcomas, which exhibit diverse histological appearance, can easily be misdiagnosed as benign tumors. Myofibroblastic sarcomas are local destructive lesions with frequent recurrence, and may metastase distantly.