Gastric wall endometriosis: A case report

Introduction Endometriosis is defined as the presence of ectopic endometrial tissue outside the uterus and generally involves the pelvis, especially the ovaries, cul-de-sac, broad ligaments, and uterosacral ligaments. Extrapelvic endometriosis occurs in 10% of diagnosed cases. Gastric endometriosis is very rare, with only six cases reported in the English literature since 2011.[1] These cases present with cyclical epigastric pain, nausea, vomiting, melena, or dyspepsia, often following abdominal or gynecologic surgery.[2-7] We report a case of gastric endometriosis in a woman of reproductive age with a history of Cesarean section. Case History A 46-year-old woman presented to the emergency department with epigastric and right loin pain, accompanied by nausea. She had a 6-month history of chronic epigastric pain and had undergone esophagogastroduodenoscopy 1 month prior, which revealed the condition of diffuse gastritis. She was treated with proton pump inhibitors but experienced little improvement in symptoms. Her surgical history includes a Cesarean section at age 23. There was no significant family medical history. In a physical examination, she had presented with mild epigastric tenderness. Her blood pressure was 163/97 mm Hg, temperature 37.3°C, and lab tests showed no anemia (12.5 g/dL, normal 12–16 g/dL), normal lipase (29 U/L, normal 0–60 U/L), amylase (69 U/L, normal 20–112 U/L), and liver function (glutamate oxaloacetate transaminase: 14 U/L, normal 8–40 U/L; glutamate pyruvate transaminase: 12 U/L, normal 8–40 U/L; total bilirubin: 0.5 mg/dL, normal 0.2–1.2 mg/dL). Abdominal ultrasonography revealed a heterogeneous mass lesion in the stomach. A computed tomography scan of the abdomen showed a large, irregular, abnormal enhancing soft tissue mass that affects the inferior wall of the gastric antrum, with many exophytic components. The mass measured 4.1 cm × 6.6 cm × 6.8 cm. [Figures 1 and 2] The differential diagnosis included gastrointestinal stromal tumor (GIST) and abdominal abscess. The patient underwent laparoscopy with excision of the mass and partial gastrectomy [Figure 3]. Histopathological examination revealed endometriosis with hemosiderin-laden macrophages and atypical endometrial stromal cells. The symptoms extended to the serosa of the stomach and colon, along with serositis. This diagnosis, based on morphological and immunohistochemical features, confirmed endometriosis.

Endometriosis is the presence of endometrial tissue outside the endometrial cavity and affects approximately 6%–10% of women of reproductive age. Extrapelvic endometriosis occurs in only 10% of cases. This case represents a rare instance of gastric endometriosis, which is difficult to diagnose due to its nonspecific symptoms.[8] Gastrointestinal endometriosis is typically characterized by the sigmoid colon and rectum, with small bowel involvement being less common (1% to 7% of gastrointestinal endometriosis cases). Gastric endometriosis, however, is exceedingly rare. In this case, the patient did not present with typical symptoms of endometriosis, such as cyclic abdominal pain corresponding with menstruation. As a result, endometriosis was not initially considered in the differential diagnosis, and preoperative confirmation of gastric pathogenesis was not obtained. Its pathogenesis remains unclear, though several theories have been proposed. Sampson’s theory of autotransplantation via retrograde menstruation is one of the most widely accepted. It suggests that endometrial fragments regurgitated through the fallopian tubes during the menstruation implant on the peritoneum and ovaries.[9,10] Gastric endometriosis is characterized by cyclical abdominal pain, nausea, vomiting, and obstruction,[11] but is often overlooked by gynecologists, as they focus primarily on the pelvis, and the stomach is not routinely examined during laparoscopy. In almost all cases of extrapelvic endometriosis, surgical resection is the first choice of treatment and usually leads to complete cure. The recurrence rate following surgery is low, at 4.3%.[12,13] In conclusion, gastric endometriosis is rare, can mimic gastric wall neoplasms, and should be considered in the differential diagnosis of gastric masses in women with chronic or cyclic epigastric pain. Ethics Statement This study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki and its amendments. The author certify that they have obtained the appropriate patient consent form. In the form, the patient has given her consent for the images and other clinical information to be reported in the journal. The patient understands that the name and initials will not be published. Author contributions Conceptualization: M.C. Chou; methodology: M.C. Chou; original draft preparation: M.C. Chou; writing—review & editing: M.C. Chou. Author M.C. Chou has read and agreed to the final version of the manuscript. Data availability statement Data sharing not applicable to this article as no dataset were generated or analyzed during this study. Financial support and sponsorship Nil. Conflicts of interests There are no conflict of interests.

Computed tomography; endometriosis; stomach