Egyptian Examples Of Soft Tissue Sarcomas,pathological And Immunohistochemical Study:

Magdy Mahmoud Nouh

soft tissue sarcomas appear in different guises and can mimic variousreactive soft tissue lesions and epithelial neoplasm thus there is a need foraccurate histological diagnosis. Many sarcomas are too poorly differentiated( undifferentiated) to exhibit morphological feature specifiec enough todefine their histogensis or true origin .So that accurate identification by morphological criteria alone is limited.Histochemical stain and immunohistochemical techniques may help to reducethe size of this category .In this work and besides the routine light microscope, we used acombination of histochemical stain confirmed by immunohistochemical stainsto improve accuracy of diagnosis . Also this study aims at evalution of theproliferative activity of different soft tissue sarcomas lesions by silver _stained nucIeolor organizer regions which correlate their results withhistological type and grade.In this study, 50 biopsy specimens of soft tissue sarcomas received atPathology Department, Benha University and Histopathology Department ofNational Cancer Institute in Cairo in three years periods from November 1995to December 1998 were used.Specimens were - re - cut, stained using hematoxylin and Eosin (H & Estain) . Special stains were resorted to Gorden and Sweets for reticulin,Masson trichrome stain for myofibrils and collagen, periodic acid Schiff stainfor glycogen and mucoproteins .Alcian blue stain for acid mucopolysaccharides, silver stainingtechniques for evaluation of AgNORs count and pattern,immunohistochemical staining using : Vimentin for mesenchymaldifferentiation, alpha-l- antitrypsin as a histocytic marker , desmin , formuscle differentiation, alpha-l- smooth muscle actin, a smooth musclemarker to differentiate between skeletal and smooth muscle .The different types of soft tissue sarcomas were categorized according totheir histopathological features. 7 cases were liposarcomas (2 myxoid, oneround cell , two well differentiated and two pleomorphic), 8 casesfibrosaraomas ( 3 well differentiated , 2 moderate differentiated, 3 poorlydifferentiated ),7 M.F.H. (5 storiform pleomorphic and 2 myxoid), 10 casesleiomyosarcomas ( 5 well differentiated, 5 poorly differentiated ) , 5rhabdomyosarcomas ( 3 embryonal and 2 alveolar) and 13 cases ofundifferentiated sarcomas ,analyzed by a panel of histochemical andimmunohistochemical stains .The AgNORs count correlate significantly and increased gradually withprogression of the grade. The mean number of AgNORs / nucleus was (1.1 /nucleus ± 0.1) in control group, (4.78 / nucleus ± 0.38) in low grade cases;( 5.89 / nucleus ± 0.78 ) in intermediate grade; ( 8.52 / nucleus ± 1.17) inhigh grade and (9.35/ nucleus ± 0.33) in undifferentiated cases.As regards the AgNORs size and distribution pattern there weredifferences between normal cells and malignant cells. Round, uniform andhas regular sized and shape in normal cells . While the malignant cells werecharacterized by irregular scattered distribution ofNORs and pleomorphic insize and shape .The immunohistochemical markers revealed that : Vimentin marks allconnective tissue cells ( classified and unclassified). Alpha-l- antitrypsinmarked all cases of M.F.H. and cases 6,7 and 8 of unclassified cases.Desmin marked all cases of both leiomyosarcomas and rhabdomyosarcomasand cases 9,10,11,12 and 13 of unclassified sarcomas. Two cases ( 1 and 4 )of unclassified cases still undiagnosed.