Introduction

Gastrointestinal stromal tumors (GIST) are sarcomas that originate in the interstitial cells of cajal¹; which are located within the muscle layer and are pacemaker cells of the gastrointestinal tract responsible for its motility².

They are mostly caused by oncogenic mutations in the receptor tyrosine kinase (KIT gene) and smaller fractions have mutations in the platelet derived growth factor receptor alpha (PDGFRA) gene³, which encode members of the family of type iii transmembrane receptor tyrosine kinases, central regulators of cell proliferation, differentiation and apoptosis pathways¹.

GISTS are rare and represent 1% to 2% of neoplasias. Gastrointestinal⁴. They can occur anywhere in the tract gastrointestinal⁵; however, they are more frequent in the stomach (51%), followed by the small intestine (36%), the colon (7%), the rectum (5%) and the esophagus (1%)². It has a incidence of one to two per 100,000 individuals and a prevalence of 13 per 100,000 individuals, of which which men and women are equally affected⁵. These tumors can arise at any age and are most common in people between the ages of 40 and 70, with a median age of 65 years^4,6.

Case report

It should be noted that the patient gave his informed consent for the report's publication. The article has been reviewed by the ethics committee and institutional permission for publication by the Hospital Regional Docente de Trujillo (HRDT).

A 62-year-old female patient from Magdalena de Cao, with a history of hospitalization at the Hospital Regional Docente de Trujillo (HRDT) from september 10 to 24, 2022, due to fainting, rectal bleeding (twice), hematemesis (three occasions) and abdominal swelling causing acute post-hemorrhagic anemia. Two globular packages were administered. An upper digestive endoscopy was performed, which failed to show evidence of a lesion causing bleeding in the esophagus, stomach, and duodenum. The colonoscopy showed the mucosa of the cecum and rectum conversed without evidence of lesions, and a CT scan revealed a solid nodule with uptake of the substance. Of contrast of exophytic growth in the jejunal wall, which suggests ruling out a gist tumor. (Figure 1)

Figure 1 Computed axial tomography (CT) scan shows a 4.2 cm × 3.0 cm mass that enhanced heterogeneously within the proximal aspect of the jejunum about 15 cm from the treitz ligament 

Likewise, an endoscopic capsule examination was performed, finding a lesion with an ulcerous impression and a subepithelial appearance. The HRDT did not have the capacity to perform an enteroscopy that could obtain a biopsy to rule out gist tumor. (Figure 2)

Figure 2 Capsule endoscopic examination where ulcerative impression lesions and subepithelial appearance are observed at time 01:10 of the procedure 

The recommendations and treatment for discharge were a soft diet and control by an external gastroenterology clinic in 2 weeks.

On october 2, the patient went to the HRDT emergency department due to transrectal bleeding of approximately 500cc, vinous red in color and with foul-smelling clots with an evolution time of one day. She was referred to the gastroenterology service for observation and evaluation. On the day of admission, a globular package was administered, giving treatment with omeprazole (40 mg iv every 12 hours for 5 days), dimenhydrinate (50 mg iv pro re nata for 5 days) and tramadol (100 mg via EVpro re natafor 5 days). Two days after the date of admission, he presented 8.9g of hemoglobin and 27.2% of hematocrit. Four days later, his hemoglobin was 11.5% and his hematocrit was 35%; therefore, he was discharged with the diagnosis of inactive midgut bleeding with soft diet treatment, 20cc lactulose orally every 24 hours and referral to Chiclayo for his enteroscopy.

On october 14, an enteroscopy was performed at the Lambayeque regional hospital where an ulcerated subepithelial lesion of approximately 3cm in diameter was found with deep ulceration at its apex whose bed presented fibrin and remains of necrosis in the proximal jejunum. A biopsy is taken and surgical treatment is suggested.

In the anatomopathological study, a spindle cell neoplasm suggestive of a gist tumor was diagnosed and an immunohistochemical study was indicated to define the lineage of the proliferating cells. (Figure 3)

Figure 3. Pathological study of the lesion in the jejunal area. 

For the surgery, she was referred to the Instituto Regional de Enfermedades Neoplásicas Norte (IREN norte) and was admitted as an emergency on november 2 for presenting her 4th rectal bleeding of approximately 250cc. In total, the patient received 7 red blood cells since the onset of the disease.

On november 6, resection of the jejunal gist tumor was performed. Among the operative findings, a tumor was found 15 cm from the angle of Treitz, a 4x3cm proliferative, extraluminal lesion that compromised 50% of the circumference of the intestinal wall of the first jejunal loop, for which we proceeded with the resection of 4 cm of intestine.

After the surgical procedure, the patient is stable and is hospitalized for follow-up until she is discharged.

The immunohistochemical result of the sample showed a positive gastrointestinal stromal tumor (GIST) for cKit/CD117. (mitotic rate <5 /5 mm). Spindle cells arranged in fascicles of intermediate cellularity with sectors of necrotic and hemorrhagic tissue, moderate-risk lesion with a size of 4.2 cm.

Discussion

GISTS are the most frequent mesenchymal neoplasms of the gastrointestinal tract, representing 0.1 to 3% of digestive tumors. Its incidence varies from 1 to 1.5 cases per 100,000 subjects per year; their age of presentation belongs to the range of 50 to 65 years and they are located in the hollow digestive viscera (80%) and in the retro-peritoneum and minor pelvis (10%)^7,9. In addition, they originate in the interstitial cells of cajal of the intestinal nerve centers (myenteric plexus) by an activating mutation of the KIT (60-85%) and PDGF (10-15%) tyrosine kinase receptors¹⁰.

In this case report, the patient is a 62-year-old woman who suffers from digestive hemorrhage in the midgut, in addition to partial obstruction and chronic bleeding. It should be noted that approximately 70% of gist cases are symptomatic at diagnosis, but there is a small percentage that requires emergency surgery as in this case⁸. Likewise, the manifestations depend on three parameters, their location, aggressiveness and size. Tumors smaller than 2 cm are usually asymptomatic, limited to the colonic wall, and visible at endoscopy as small submucosal masses¹¹. Among the operative findings of the case, a tumor was found 15 cm from the angle of treitz, a 4x3 cm extraluminal proliferative lesion that compromised 50% of the circumference of the intestinal wall of the first jejunal loop.

The most common complication of large GISTS is gastrointestinal bleeding secondary to mucosal ulceration, as occurred in this case, the main reason for the patient's consultation being rectal bleeding caused by the pelvic mass. Because GISTS range from benign to highly aggressive, risk stratification schemes based on prognostic factors such as size, site of origin, mitotic count, and proliferation index have been proposed¹². Also, the diagnosis of bleeding jejunal GISTS is challenging due to their inaccessibility by endoscopy; for this reason, the immunohistochemical analysis of the samples was chosen, where they expressed cd117 (95%), cd34 (60-70%) and smooth muscle actin alpha (20-40%), as well as positive vimentin and negative desmin to differentiate them. Of melanomas and plasmacytomas¹³. And, given the finding of nonspecific abdominal pain and other nonspecific gastrointestinal signs and symptoms, gastrointestinal bleeding, resistance to treatment, and coexistence of an abdominopelvic mass, this type of tumor should be considered in the differential diagnosis. Timely diagnosis and treatment will help improve the patient's chances of survival.