Introduction and importance: Spontaneous hemoperitoneum (SH) is a rare, life-threatening condition characterized by nontraumatic and non-iatrogenic intraperitoneal bleeding. This article explores three unique cases of SH, shedding light on unusual causes and emphasizing the critical role of diagnostic imaging and exploratory laparotomy in management.
METHODS: The study was a retrospective single-center non-consecutive case series.
RESULTS: We report three distinct cases of SH, each originating from uncommon sources: rupture of greater omentum arterio-venous malformation, a branch of the left gastric artery, and pathological splenic rupture. Clinical evaluation, diagnostic imaging, and surgical interventions are detailed for each case.
CONCLUSIONS: These rare cases underscore the diverse etiologies of SH, including idiopathic omental bleeding, gastric intramural hematoma, and atraumatic splenic rupture. Enhanced CT imaging plays a crucial role in diagnosis, enabling the characterization of underlying pathologies. Exploratory laparotomy proves to be an essential treatment option for unstable patients with suspected or confirmed diagnoses of SH.

BACKGROUND: Gastric intramural hematoma is a rare disease. Here we report a case of spontaneous isolated gastric intramural hematoma combined with spontaneous superior mesenteric artery intermural hematoma.
METHODS: A 75-years-old man was admitted to our department with complaints of abdominal pain. He underwent a whole abdominal computed tomography (CT) scan in the emergency department, which showed extensive thickening of the gastric wall in the gastric body and sinus region with enlarged surrounding lymph nodes, localized thickening of the intestinal wall in the transverse colon, localized indistinct demarcation between the stomach and transverse colon, and a small amount of fluid accumulation in the abdominal cavity. Immediately afterwards, he was admitted to our department, and then we arranged a computed tomography with intravenously administered contrast agent showed a spontaneous isolated gastric intramural hematoma combined with spontaneous superior mesenteric artery intermural hematoma. Therefore, we treated him with anticoagulation and conservative observation. During his stay in the hospital, he was given low-molecular heparin by subcutaneous injection for anticoagulation therapy, and after discharge, he was given oral anticoagulation therapy with rivaroxaban. At the follow-up of more than 4 months, most of the intramural hematoma was absorbed and became significantly smaller, and the intermural hematoma of the superior mesenteric artery was basically absorbed, which also confirmed that the intramural mass was an intramural hematoma.
CONCLUSIONS: A gastric intramural hematoma should be considered, when an intra-abdominal mass was found to be attached to the gastric wall. Proper recognition of gastric intramural hematoma can reduce the misdiagnosis rate of confusion with gastric cancer.

Intramural intestinal hematoma is a rare disease, one of the triggering factors of which is the use of anticoagulants. In previous reports, most patients were on treatment with warfarin. Herein, we report a case of direct-acting oral anticoagulant (DOAC)-induced intramural hematoma of the ascending colon in a patient refractory to conservative treatment and required laparoscopic right hemicolectomy. An 80-year-old male patient with a history of atrial fibrillation and cerebral infarction, on treatment with apixaban, was brought to our hospital with the chief complaints of abdominal pain, vomiting, and melena. Imaging revealed the cause of symptoms to be intestinal obstruction caused by a mass lesion on the wall of the ascending colon. We initially opted for conservative treatment with discontinuation of apixaban and insertion of an ileus tube. Intestinal dilatation findings showed improvement; however, subsequent imaging examinations did not reveal the shrinkage of a lesion in the ascending colon. If the mass was not removed, recurrence of bowel obstruction symptoms was expected, so we decided to perform surgical intervention. A laparoscopic right hemicolectomy was performed, and an intramural hematoma of the ascending colon was diagnosed based on the excised specimen. He needed a blood transfusion for anemia but was discharged on postoperative day 14 with no other complications. DOACs are now widely used in patients with atrial fibrillation, and the risk of bleeding as a side effect is extremely low compared to conventional anticoagulants, including warfarin. However, when abdominal pain occurs, as in the present case, an intramural hematoma should be considered in the differential diagnosis. There is no established treatment plan for intestinal intramural hematoma. Although conservative treatment is effective in some cases, it is difficult to evaluate the risk of bleeding associated with DOACs using coagulation tests. Even if conservative treatment is selected, it is essential to determine surgical resection, if necessary, based on the clinical course and imaging and blood test findings.

Gastric intramural hematoma (GIH) is a contained hemorrhage located within the layers that comprise the wall of the stomach. It is a rare condition that has a variety of etiologies. Pancreatitis-induced GIH is an even rarer phenomenon, with only a handful of documented cases in the medical literature. In the current case, a patient presented with chronic abdominal pain for the past two months, with an acute worsening of symptoms. CT imaging confirmed a large, stable GIH with concomitant pancreatitis, likely alcohol-induced. Diagnostic laparoscopy was performed in response to worsening hemodynamic status, which confirmed hemorrhagic pancreatitis as the likely cause of the GIH formation. Jackson-Pratt (JP) drains were placed, and the patient was subsequently discharged. The patient returned one month later with an acute exacerbation of pancreatitis; however, interval improvement of the GIH was observed. The patient was transferred to outpatient care for continued conservative treatment without any further return visits.

Spontaneous gastric intramural hematoma is a rare disease. Herein, we present a case of a previously healthy 28-year-old male patient who presented with diarrhea and diffuse abdominal pain of one-week duration. The patient was diagnosed with spontaneous gastric intramural hematoma post urgent partial gastrectomy for a bleeding gastric tumor. Six other cases of spontaneous gastric intramural hematoma are published in the literature; therefore, when encountering a case of intra-abdominal mass attached to the gastric wall, gastric intramural hematoma should be considered in the differential even when no cause is present.

BACKGROUND: Gastric hematoma is a rare disorder. Here we report a case of a large gastric intramural hematoma mimicking an impending rupture of a visceral artery aneurysm.
METHODS: A 60-year-old Japanese woman complained of left flank pain. Computed tomography with intravenously administered contrast agent showed a solid mass of 5 × 5 × 8 centimeter in the left middle abdominal quadrant. On completion of computed tomography, the working diagnosis was an impending rupture of an aneurysm located in a branch of the superior mesenteric artery. Transcatheter arterial embolization was performed, but angiography of the superior mesenteric artery and the inferior mesenteric artery did not indicate extravasation of the contrast agent and we did not observe any aneurysmal structure. We decided to perform surgery. The operational findings revealed that the mass was a gastric intramural hematoma.
CONCLUSIONS: On encountering an intra-abdominal mass found to be attached to a gastric wall, a gastric intramural hematoma should be considered.

Gastric intramural hematoma is a rare injury of the stomach, and is most often seen in patients with underlying disease. Such injury following endoscopic therapy is even rarer, and there are no universally accepted guidelines for its treatment. In this case report, we describe a gastric intramural hematoma which occurred within 6 h of endoscopic mucosal resection (EMR). Past medical history of this patient was negative, and laboratory examinations revealed normal coagulation profiles and platelet count. Following EMR, the patient experienced severe epigastric pain and vomited 150 mL of gastric contents which were bright red in color. Subsequent emergency endoscopy showed a 4 cm × 5 cm diverticulum-like defect in the anterior gastric antrum wall and a 4 cm × 8 cm intramural hematoma adjacent to the endoscopic submucosal dissection lesion. Following unsatisfactory temporary conservative management, the patient was treated surgically and made a complete recovery. Retrospectively, one possible reason for the patient\'s condition is that the arterioles in the submucosa or muscularis may have been damaged during deep and massive submucosal injection. Thus, endoscopists should be aware of this potential complication and improve the level of surgery, especially the skills required for submucosal injection.