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Case Report Low gastrointestinal tract bleeding secondary to low-grade gastrointestinal stromal tumor: case report

it is difficult to predict their biological behavior (benign / malignant), other prognostic morphological variables consider mucosal involvement, presence of necrosis, hypercellularity, cellular pleomorphism and anatomical localization. 1-10 We present the case of a patient with low gastrointestinal tract bleeding secondary to a gastrointestinal stromal tumor, as well as her diagnostic clinical approach in a third-level medical unit, as well as a brief review of the literature. ABSTRACT Gastrointestinal stromal tumors (GIST) are neoplasms of mesenchymal origin. We present the case of a patient with low gastrointestinal tract bleeding secondary to a gastrointestinal stromal tumor, as well as her diagnostic clinical approach in a third-level medical unit, as well as a brief review of the literature. The treatment of this neoplasm is surgical and ideally consists of complete resection with negative margins (R0). GISTs mostly affect patients between 4-6 decades of life with a slight predominance in women, with the stomach and small intestine being the most frequently affected organs. The immunohistochemical study shows positivity for c-KIT and CD34 in 100% and 63% of cases. The treatment is surgical which usually by maintaining free margins is curative


INTRODUCTION
Gastrointestinal stromal tumors (GIST) are neoplasms of mesenchymal origin, until 2 decades ago they were called with various names according to their histopathological differentiation of smooth muscle (leiomyoma, leiomyoblastoma or leiomyosarcoma) or neural (schwannoma); thanks to subsequent studies of immunohistochemistry, electron microscopy and molecular biology it was possible to reclassify these tumors as a clinical-pathological entity characterized immunohistochemically and unlike other tumors of smooth and neural muscle origin, by expressing in 95% of cases the transmembrane receptor for the factor derived from stem cells with activity on the receptor tyrosine kinase known as CD117 or c-KIT, located on chromosome 4q11-q12 and composed of 21 exons, being mutations at the level of exon 11 (67%) and 9 (11%) the most frequently detected. GISTs generally affect subjects between the 4 th -6 th decades of life with a slight predominance in the male population, corresponding to approximately 0.1-0.3% of all neoplasms of the digestive tract with an estimated incidence and prevalence of 14.5 and 129 cases per million inhabitants respectively; representing 80% of gastrointestinal mesenchymal neoplasms. [1][2][3][4][5] Mitotic count and tumor size are the main prognostic factors identified related to disease progression and survival, it is difficult to predict their biological behavior (benign / malignant), other prognostic morphological variables consider mucosal involvement, presence of necrosis, hypercellularity, cellular pleomorphism and anatomical localization. [1][2][3][4][5][6][7][8][9][10] We present the case of a patient with low gastrointestinal tract bleeding secondary to a gastrointestinal stromal tumor, as well as her diagnostic clinical approach in a third-level medical unit, as well as a brief review of the literature.

CASE REPORT
A 69-year-old female with a surgical history of hysterectomy for uterine myomatosis 20 years ago and left kidney cyst drainage 10 years ago. Transfusions: July 30, 2021; 6 globular packages for bleeding from the lower digestive tract. Hospitalizations: 30.07.21, Admission for hypovolemic shock due to bleeding from the lower digestive tract, panendoscopy with non-active ulcer, treatment with amines and hemo-transfusion, omeprazole and sucralfate. It begins on 29.08.21 with malaise, asthenia, adinamia, nausea, melenic evacuation, of moderate amount, Bristol 3 to 4, later with hematochezia on two occasions. Denying another symptomatology, he reports loss of 3 kg in the last 3 months. Anterograde enteroscopy (01/02/2022): at the level of the proximal jejunum a thickened mucosal lesion is observed with a change of coloration of 7mm with bleeding when taking biopsies that is self-limited, 10 cm from the lesion there is another elevated, friable, ulcerated lesion of 20 mm in diameter which a single biopsy of 3 mm is taken not being possible to take complete by active bleeding of arterial type, 2 hemoclips are placed with cessation of bleeding.

Pathology results
It is received in a bottle with formalin identified with the patient's data tumour biopsy in jejunum consisting of multiple tiny, soft, irregular and whitish fragments that together measure 0.

Tomography on 12/03/2022
Four nodules located in the anterior segment of the right upper lobe and in the postero-basal segment of the right lower lobe are observed, irregular morphology, spiculated edges and solites, the greater than 12 mm in its major axis in the axial plane. Laminar and segmental atelectasis ( Figure 3).

DISCUSSION
The clinical manifestations of GIST are various, the size, and the location of the tumor can affect the clinical manifestations of the patients. The most common clinical manifestations are gastrointestinal (GI) bleeding and abdominal discomfort. Patients with GI bleeding usually need emergency surgery, so it is of great significance to analyze the effect of GI bleeding on the prognosis of patients with GIST. 8 In the immunohistochemical study, GIST are characterized by expressing c-KIT with only a small percentage (<5%) that are negative, the absence of this marker in the presence of a suggestive histological pattern does not rule out the diagnosis. The treatment of this neoplasm is surgical and ideally consists of complete resection with negative margins (R0), depending on the location, size and involvement of neighboring structures, dissection of lymph nodes is not recommended, given the infrequent involvement and dissemination more frequently by hematogenous route with hepatic involvement. [2][3][4][5]7,8 CONCLUSION GISTs mostly affect patients between 4-6 decades of life with a slight predominance in women, with the stomach and small intestine being the most frequently affected organs. The immunohistochemical study shows positivity for c-KIT and CD34 in 100% and 63% of cases. The treatment is surgical which usually by maintaining free margins is curative. To date, however, guidelines have to be standardized, and the need for a timely diagnosis is highlighted to establish optimal management, individualized for each patient, and the importance of referring them to a center with the resolution capacity as a third level of attention.