ABSTRACT
<p><b>OBJECTIVE</b>To study the clinicopathologic and immunohistochemical features of mesenchymal chondrosarcoma.</p><p><b>METHODS</b>The clinical and histologic features of 23 cases of mesenchymal chondrosarcoma were analyzed. Immunohistochemical study was also performed in 14 of the cases.</p><p><b>RESULTS</b>The age of patients ranged from 12 to 47 years. Fourteen of them occurred in males. Thirteen cases involved the bony skeleton and 5 cases affected the soft tissue. The patients presented with pain and/or swelling. Histologically, the tumor consisted of a mixture of undifferentiated small round cells and hyaline cartilage. Transition between the two components was demonstrated and growth plate-like cartilage was observed. Immunohistochemical study showed that the small round cells were positive for Sox9 (14/14), CD99 (12/14), vimentin (6/14), CD56 (4/14), CD57 (4/14), neuron-specific enolase (3/14) and desmin(1/14). They were negative for Coll-II, S-100 protein, epithelial membrane antigen, pan-cytokeratin, synaptophysin, chromogranin A, CD34 and c-erbB2.</p><p><b>CONCLUSIONS</b>Mesenchymal chondrosarcoma is a rare malignant tumor. Thorough histologic examination, when coupled with immunohistochemical findings, is helpful in arriving at a correct diagnosis.</p>
Subject(s)
Adolescent , Adult , Child , Female , Humans , Male , Middle Aged , Young Adult , 12E7 Antigen , Antigens, CD , Metabolism , Bone Neoplasms , Diagnostic Imaging , Metabolism , Pathology , General Surgery , Cell Adhesion Molecules , Metabolism , Chondrosarcoma, Mesenchymal , Diagnostic Imaging , Metabolism , Pathology , General Surgery , Follow-Up Studies , Immunohistochemistry , Lung Neoplasms , Mediastinal Neoplasms , Diagnostic Imaging , Metabolism , Pathology , General Surgery , Neoplasm Recurrence, Local , Orbital Neoplasms , Diagnostic Imaging , Metabolism , Pathology , General Surgery , Radiography , SOX9 Transcription Factor , Metabolism , Vimentin , MetabolismABSTRACT
<p><b>BACKGROUND</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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 eosinophilic 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.</p><p><b>CONCLUSIONS</b>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.</p>