B DOĞANAVŞARGİL, T. AKALIN, M. SEZAK, B. M. ALKANAT, G. KANDİLOĞLU, M. TUNÇYÜREK

Gastrointestinal stromal tümörlerde histopatolojik değerlendirme “Ege Üniversitesi Tıp Fakültesi Patoloji Anabilim Dalı'nın 1992-2007 yılları arasındaki deneyimi”

Giriş: Gastrointestinal stromal tümörlerin (GİST), tanısında ve tedavisinde katedilen önemli aşamalara rağmen, biyolojik davranışı öngörmede hala güçlükler yaşanmaktadır. Çalışmamızda Anabilim Dalı'mızda değerlendirilen GİST olgularının, histolojik ve immunfenotipik özelliklerinin ortaya konması ve Fletcher ve arkadaşlarınca önerilen “Agresif davranış-risk kategorilerileri”nin belirlenmesi hedeflenmiştir. Gereç ve Yöntem: Çalışmanın birinci aşamasında 1992-2000 yılları arasında gastrointestinal mezenkimal tümör tanısı almış 53 olgu, GİST olasılığı açısından immunhistokimyasal yöntemle (CD117-KIT protein, CD34, desmin, düz kas aktini, S100 ve Ki-67) yeniden incelenmiş, 11 leiomyoblastom, 5 malign leiomyoblastom, 8 epiteloid leiomyosarkom, 3 leiomyosarkom, 7 mezenkimal tümör ve 9 leiomyom olgusu bugünkü kriterler ile GİST olarak sınıflandırılmıştır. İkinci aşamada çalışma grubundaki toplam 122 olguda, tümör çapı ve 50 büyük büyütme alanındaki (BBA) mitoz sayılarından yararlanılarak risk tayini yapılmıştır. Tartışma ve Sonuç: Lezyonlar en sık mide (n=58), ince barsak (n=30) ve omentum-periton (n=19) yerleşimli olup, tümör çapı 0, 3-45 cm, mitoz sayısı 0-120 arasında değişmektedir (ortalama: 9, 77 ± 7, 27 cm, 10, 62 ±17, 64 mitoz/ 50 BBA). Olguların 7'si (%5, 7) “çok düşük riskli”, 28'i (%23) “düşük riskli”, 21'i (%17, 4) “orta derecede riskli”, 62'si (% 50, 8) ise “yüksek riskli” kategoridedir. 2002 yılından itibaren olgu sayılarında belirgin ve sabit bir artışın bulunduğu dikkati çekmektedir. Bunda tümörlerle ilgili farkındalığın artışının da önemli rol oynadığı düşünülmüştür. Çalışmamız, genel histopatolojik özelliklerin belirlenmesine yönelik bir ön çalışma niteliğinde olup, bu konuda üniversitemiz bünyesinde ya da ulusal düzeyde yapılacak olan retrospektif ya da prospektif klinikopatolojik araştırmalara katkıda bulunmak amacıyla gerçekleştirilmiştir.

Histopathologic evaluation in gastrointestinal stromal tumors, “The Experience of Ege University Faculty of Medicine Department of Pathology, 1992-2007”

Introduction: Despite remarkable progress in diagnosis and treatment of gastrointestinal stromal tumors (GIST), there are still difficulties predicting the biologic behaviour of the disease. We intented to assess the histologic and immunhistochemical features of the cases, evaluated in our department and define their “agresive behaviour” risk categories as proposed by Fletcher et al. Materials and Methods: In the first step of the study, 53 tumors diagnosed under “gastrointestinal mesenchymal tumor” category between years 1992-2000 were reevaluated immunohistochemically (CD117, CD34, desmin, smooth muscle actin, S100 and Ki-67) and 11 leiomyoblastoma, 5 malign leiomyoblastoma, 8 epitheloid leiomyosarcoma, 3 leiomyosarcoma, 7 mesenchymal tumor and ve 9 leiomyoma were reclassified under GIST. In the second step, risk assessment was done considering the size and number of mitosis evaluated in 50 high power fields in a study group of 120 cases. Results and Discussion: Tumors were mostly located in stomach (n=58), small bowel (n=30) and omentum-periton (n=19). The size of them ranged 0.3-45 cm while the number mitosis ranged 0-120 (mean : 9.77 ± 7.27 cm, 10.62 ±17.64 mitosis/ 50 HPF). Seven of the cases (%5, 7) were in “very low risk while 28 of them (%23), 21 of them (%17, 4) and 62 of them (% 50, 8) were categorised under “low risk”, “intermediate risk” and “high risk” categories respectively. A prominent and constant increase in number of cases was observed after 2002 which can also be related to the increased awareness on the issue. The study was planned as a pilot study and performed to promote future studies that will be held faculty-wide or nationwide

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