A histopathological and immunohistochemical approach of surgical emergencies of GIST. An interdisciplinary study.

: The tailored approach to gastrointestinal stromal tumors (GISTs) has led to better prognosis for these types of tumors. Also, finding out GIST's pathology has led to a better understanding of oncogenesis and cancer therapy in general. The rapid expansion of molecular and pathological knowledge of GISTs has given this disease a promising future. We analyze 30 cases of GISTs operated on in our clinic with confirmed diagnosis by immunohistochemistry. Most of the cases were acute cases that required urgent surgical therapy. An extended analysis of these cases is performed in order to underline their special features. We recorded 17 GISTs of the stomach, 12 GISTs of the small bowel and one esophageal GIST. Of the 30 cases, 15 cases required urgent surgery presenting with GI bleeding or shock following intraperitoneal rupture and bleeding or intestinal obstruction. Of the 15 cases that required urgent surgery 12 cases presented with serosal involvement. Twenty-four cases presented spindle cell histology, four cases were epithelioid and two cases presented mixed cellularity. Although acute presentation of GISTs is not the rule, 15 of 30 of our cases required immediate surgery and a high proportion of them (12/15) presented with serosal involvement. Serosal involvement may warrant the need for a macroscopic classification of GISTs and correlation to therapy. While overall mortality was not high in our series, morbidity is affected by acute presentation, though not specifically pertaining to the diagnosis of GIST. Acute presentations were more frequent, in our series, for small bowel GISTs, compared to gastric GISTs. Serosal involvement was more frequent in the group with acute presentation compared with non-acute GISTs and was present at the most cases of small bowel GISTs with acute onset. The Ki-67 index showed no difference between acute and non-acute onset of GISTs.