Watermelon Stomach - Presentation and Diagnosis

Introduction:

Watermelon Stomach (WS) is an uncommon disease characterized by prolonged gastrointestinal blood loss. Endoscopic procedures frequently miss the findings. Patients develop severe iron deficiency anemia and are typically transfusion-dependent. Rider et al. reported the first incidence of gastric vascular ectasia in 1953, observing "an erosive kind of atrophic gastritis with significant veno-capillary ectasia" in a gastrectomy specimen from an old woman with occult gastrointestinal bleeding. Although it has been linked to various medical disorders, including hepatic, renal, and cardiac illness, its pathophysiology remains unexplained. Several individuals were later found to have vascular lesions of the stomach manifesting as "red linear streaks" or "red regions with the appearance of dilated blood vessels" in the antrum. Jabbari et al. developed the acronym WS in 1984 after describing typical endoscopic findings of stomach antral ectasia (longitudinal red columns).

What Are the Clinical Presentations and Associated Illnesses?

• WS is becoming well-recognized as a significant source of occult gastrointestinal blood loss. The typical patient is an older female with a history of chronic iron deficiency anemia without explanation identified despite endoscopic and barium investigations.

• A recent analysis shows a 3:1 female prevalence, an 88 percent incidence of iron deficiency anemia, and a 42 percent incidence of heme-positive feces. Melena (stools are in dark color), hematochezia (blood passes through the anus), and hematemesis (blood is seen in the vomiting) are all often related symptoms upon presentation.

• Although blood loss seldom increases by 25 mL (milliliters) per day, dietary iron supplements are typically insufficient, and patients commonly require blood transfusions. Other distinct features include hypergastrinemia (increase in the level of gastrin), hypochloremia (acids in the stomach are low), and total achlorhydria (absence of HCL in the gastric juices) in 35 percent of cases. Atrophic gastritis is nearly uniform, which frequently leads to a misdiagnosis.

• Furthermore, WS patients had more severe liver disease, higher gastrin levels, and more chronic blood loss than portal hypertensive gastropathy (PHG) patients. Other WS-related liver illnesses have been reported, including primary biliary cirrhosis and nodular regenerative hyperplasia.

• Renal dysfunction, diabetes mellitus, hyperthyroidism, and high blood pressure (HTN) have also been linked to WS.

How Does a Watermelon Stomach Appear Under a Microscope?

• The histologic characteristic of WS is gastric antral mucosal hyperplasia of superficial fibrous muscles with capillary ectasia and thrombosis of microvasculature in the lamina propria.

• The antrum's hypervascularity is due to a large number of moderately dilated capillaries and a few extremely big capillaries. Fibrin microthrombi occlude the majority of the mucosal and submucosal telangiectatic capillaries.

• A lack of inflammatory cells and focal areas of intestinal metaplasia distinguishes the antral mucosa. Fibromuscular hyperplasia of the lamina propria is caused by the spindle cell proliferation that spreads toward the antral glands.

• Smooth muscle often extends perpendicularly into the fibrosed lamina propria, which is frequently hyalinized. The lower lamina propria is also populated by islands of typical neuroendocrine cells.

• There is a substantial increase in both intraepithelial and extra epithelial neuroendocrine cells that are reactive to serotonin (5-hydroxytryptamine -5HT3) and vasoactive peptide.

• Finally, the stomach antrum submucosa has tortuous dilated veins that stretch longitudinally toward the pylorus. These arteries are clogged and surrounded by stroma that is loosely connected.

How Does a Watermelon Stomach Occur?

• The cause of the watermelon stomach is unclear. It is unknown if angiodysplasia is a basic pathologic process or a complication of fibromuscular hyperplasia. According to the first explanation, angiodysplasia causes the connection of the distal gastric mucosa to the muscularis externa to relax, making it more prone to prolapse and damage. This, in turn, may cause reactive muscle hyperplasia and lamina propria fibrosis.

• In reality, angiodysplasia may be caused by precapillary sphincter malfunctioning, which results in hyperplasia and dilatation of the capillaries. Elevated gastrin levels cause persistent sphincter relaxation of the sphincter may lead to local hyperplasia as well as dilation of the capillary and veins.

• The gastric mucosa's ectatic vasculature is accompanied by neuroendocrine cells that release chemicals such as 5HT-3 and gastrin.

• According to several ideas of WS etiology, fibromuscular hyperplasia is the initiating phase that leads to angiodysplasia and, eventually, gastrointestinal bleeding. The proliferation of the spindle cells and hyperplasia may result from hypergastrinemia. Increased stomach peristalsis causes repetitive mechanical strains and may result in fibromuscular hyperplasia.

• As a result of the chronic low-grade occlusion of submucosal veins inside hypertrophied muscle layers causes, hydrostatic pressure rises, and veins, venules, and capillaries gradually dilate. Submucosal artery dilatation is accompanied by alterations in the mucosal vascular unit, resulting in classic angiodysplasia.

• Fibrin microthrombi can produce localized ischemia of the stomach mucosa, leading to vascular erosion and bleeding.

• Angiodysplasia appears to be a frequent vascular lesion caused by mechanical or humoral sources. Gastric acid or intraluminal food can cause clinically substantial bleeding by producing mucosal epithelium trauma overlaying engorged arteries.

How Is WS Diagnosed?

• Longitudinal antral folds with prominent columns of tortuous red, ectatic vessels called the "watermelon stripes.” Little marginated red patches clearly define these lesions. When endoscopic biopsies are performed, blanching of the vessels takes place, and it bleeds profusely.

• Most patients have an antral disease characterized by typically elevated convoluted ridges surrounded by ectatic vascular tissue radiating from the pylorus-lesions organized in radiating flat stripes distributed by numerous mucosal lesions or a combination of the above patterns.

• It has been proposed that non-cirrhotic individuals are more likely to have linear lesions inside the antrum, while cirrhotics have a more widespread disease.

• Pyloric mucosa prolapse is another endoscopic finding in WS. At the apex of the mucosal prolapse, ectatic elongated arteries and petechial (pinpoint bleeding spots on the skin) hemorrhages are common.

• Additional findings include proximal gastric involvement, two-thirds of individuals having a diaphragmatic hernia, and atrophic gastritis in uninvolved stomach regions.

What Is the Treatment of WS?

• If the diagnosis of the watermelon stomach is made early - iron supplements are enough.

• Regular blood transfusions or iron replacement supplements are given to address the related iron deficiency anemia.

• Drugs are given to reduce bleeding caused by the watermelon stomach. However, additional study is needed to determine the long-term efficacy and safety of these drugs.

• Drugs used to manage watermelon stomach, include the corticosteroids, hormone therapy, octreotide (Mycapssa), Tranexamic acid, and Thalidomide are not recommended for pregnancy or may get pregnant while taking them.

• Doctors might also utilize other endoscopic therapies to arrest bleeding. These treatments include:

  • Argon plasma coagulation (APC).

  • Endoscopic band ligation (EBL).

  • Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser coagulation.

  • Cryotherapy.

  • Radiofrequency ablation (RFA).

Conclusion:

In elderly patients with severe anemia and occult or persistent gastrointestinal bleeding, especially in the presence of heart, liver, or renal illness, WS is a crucial diagnosis to evaluate. WS can be missed as a treatable cause of gastrointestinal bleeding due to other common causes of gastrointestinal bleeding. Watermelon stomach therapy comprises a variety of drugs as well as endoscopic procedures. If these therapies do not work, a person may need surgery.