Clinico-Pathological Characteristics of GIST of Stomach along with Evaluation of their Immunohistochemical Features

Abstract

Introduction: Gastrointestinal stromal tumors (GISTs) are the most common neoplasms and they originate in the interstitial cells of Cajal. Determining morphological and immunohistochemical features remains paramount in the diagnostic approach to patients with GIST suspicion. The most common histopathological subtype is the spindle cell type followed by epithelioid cell type.  Current important immunohistochemical panel for GIST includes CD117, DOG-1, SMA and CD34; with CD117 (C-Kit) being the most sensitive and specific marker for GIST. 

Methods: We studied 31 cases of GIST of stomach diagnosed in combined Haemotoxylin and Eosin and immunohistochemistry. Immunohistochemistry for Ki-67 (Proliferative index) along with CD 117, DOG-1 and CD34 were evaluated and the results were recorded. 

Results: The age group ranged from 40 year to 80 years with an average of 53 years. Out of the 31 cases; the male to female ratio was 1.3:1. The average diameter of the tumor was 8.7cm. On histological examination; spindle cell pattern was the most common accounting for 77.41% of the cases followed by epithelioid pattern accounting for 11.90% of the cases. Most of the cases showed positivity for CD117; 27 cases (87.09%). 4 cases (12.90%) which were CD 117 negative showed positivity for DOG-1. CD34 was seen in 45% of the cases.

Conclusion: The commonest histomorphological pattern was spindle cell pattern accounting for 77.41% of the cases. C-Kit immunostaining showed positivity in 87.09 % of the tumors in this study. The immunohistochemical results in our study on stomach GIST are comparable to both local and international studies.