GIST (Gastrointestinal Stromal Tumors): As a differential diagnosis of adnexal tumors

Abstract

Introduction: GIST are the most frequent variety of mesenchymal tumours of the digestive tract, but they hardly represent 1 to 3% of the malignant gastrointestinal neoplasms. Their estimated prevalence is 15-20 cases per million (the incidence of GIST in Spain is 457 new cases per year) and it affect to patients at sixty-year old median age. Half of the cases occur in the stomach; this half may also be confined to an specific organ, like small intestine (30%), rectum (5%) and colon (2%); Occasionally the primary GIST may occur in the peritoneum, pancreas, ovaries, uterus or prostate. GIST main symptom may be either a painful mass or unspecific symptomatology; nonetheless, bleeding and obstruction must be considered as well. The diagnosis must be histopathologic and its confirmation immunohistochemical: 95% of GIST reacts positively to KIT or CD117. The malignant behaviour of the tumour is determined by its size and the mitosis images. Material and methods: We present a case of GIST, that was proposed for an intraoperative biopsy after a diagnosis of an adnexal tumor with suspicious of malignancy, with both markers and imaging tests. Results: Woman of 60 years old, from Colombia, who complains us because a clinical revision, completly asympthomatic. She had a previous gynaecological control 2 years before, without anything remarkable. Nulligravida with menopause at 45 years old. - Gynaecological exploration: Increased size of the left adnexal area. - Gynaecological ultrasound: increased size of the left ovary, of 67x 42 mm, with an irregular contour, with inside areas of mixed echogenicity, hyperechogenicity (with shadowing) and with papillary formations inside the echonegative ones; abundant Doppler color signal inside the tumor, with predominantly venous morphology (IR 0.6). Both uterus and left ovary were described as normal. There was no pelvic liquid during the examination. CT abdpelvic: In small pelvis, adjacent to the uterine fundus, displayed two ovoid lesions of 3.5 and 4.2 cm of heterogeneity behavior, with big calcifications, presenting the one of smaller size some hypoenhancing areas. Because of the morphological appearance they could correspond to subserosal fibroids. Ovaries are not displayed. Intestinal loops with distribution and morphological apparently normal. Multiple intrahepatic LOES, radiologically indeterminate. Rest of the study without any alteration. - Tumor markers: Both CEA and CA 125 were normal. CA 19.9 was high: 635.8 U / ml. - Laparoscopy: we visualized a lobulated, hard and highly vascularized mass that was pedunculated in an intestinal loop, located at the pelvis, of 5 cm of diameter, very close to the left adnexal area. Uterus and both ovaries were macroscopically normal. Discussion: In the differential diagnosis of adnexal tumors we must consider the possible non gynaecological origin, including those of intestinal origin. A very specially preoperative evaluation must be performed before the surgery in order to explain to our patient the suspected pathology, the posible surgery and the postoperative cares.