Brunner’s Gland Hyperplasia - Classification, Clinical Manifestations, Diagnosis, and Treatment

What Is Brunners Gland?

Brunner's glands are exocrine glands (glands with ducts) found in the submucosa of the duodenum. They are majorly seen in the first part of the duodenum. They secrete an alkaline fluid containing mucin that protects the duodenum from acid contents that enter the duodenum from the stomach.

What Is Brunners Gland Hyperplasia?

Brunner's gland hyperplasia is a rare lesion of the duodenum. It is benign and does not cause any symptoms. Instead, it causes symptoms like gastrointestinal bleeding and abdominal pain. It mainly affects the proximal part of the duodenum. Most of this lesion is pedunculated (with a stalk at the base) and 1 to 2 cm (centimeters) in diameter; however, large tumors have also been reported.

What Are the Causes of Brunner's Gland Hyperplasia?

The etiology of the disease is unknown; however, based on research work, hyperacidity and the presence of Helicobacter pylori are the main reasons for this lesion. Other causes can be chronic tissue inflammation and a decrease in pancreatic function.

What Are the Signs and Symptoms of Brunners Gland Hyperplasia?

Specific symptoms are absent in Brunner's gland hyperplasia, and patients present with vague symptoms that may be related to abdominal problems. The symptoms are mentioned below:

• Pain in the upper abdomen just below the ribs (epigastric pain).

• Bloating and swelling in the abdominal region (abdominal distension).

• Indigestion or dyspepsia.

• Gastrointestinal hemorrhages result in iron deficiency anemia.

• Intestinal obstruction (a condition in which the digestive material does not pass to the large intestine).

• Accelerated peristalsis (a problem in digestion leading to diarrhea).

• Duodenal intussusception (a life-threatening condition in which the proximal duodenum slips over the distal duodenum).

• Dark color stool (melena) and hematemesis (blood in the vomit) are less frequently seen symptoms caused due to erosion of the tumor.

What Is the Classification of Brunners Gland Hyperplasia?

Based on Histopathology-The histopathological classification of Brunner's gland hyperplasia is not well-defined, and hence there is no distinct differentiation between the terms hyperplasia, hamartoma, adenoma, and Brunneroma. According to the research, lesions less than 1 cm represents hyperplasia, lesions more than 1 cm is called an adenoma, and lesions that contain a mixture of muscular and fatty tissue are called hamartoma.

Based on Glandular (Related to Gland) Proliferation or Feyrter Classification- Three distinct types of Brunner gland hyperplasia have been identified.

• Type 1- Diffuse, nodular hyperplasia, which occupies most of the duodenum and mimics malignancy.

• Type 2- Circumscript, nodular hyperplasia, mainly occupying the duodenal bulb.

• Type 3- Adenomatous hyperplasia, which can be sessile (without stalk) or pedunculated (with stalk)

What Are the Conditions Associated (Side Effects) With Brunners Gland Hyperplasia?

• Uremia (a condition in which the kidneys do not function properly, so waste products are released into the blood).

• Chronic Pancreatitis (inflammatory condition of the pancreas resulting in damage to the pancreas).

• Helicobacter pylori Infections

• Adenocarcinoma (in rare cases)- It is a malignant condition of the glandular epithelial cells. Brunner's gland shows increased p53 antigen expression, a tumor marker.

What Are the Diagnostic Tests for Brunners Gland Hyperplasia?

• Endoscopy- Brunner's gland hyperplasia is an incidental finding during endoscopy. They appear as mucosal protrusions or polyps upon endoscopic examination.

• Biopsy- Hyperplastic glandular mass is excised using upper endoscopy and sent for biopsy. Biopsies provide indeterminate results and are of limited value in making a diagnosis. Research shows cases of incorrect diagnosis based on biopsy reports. It is mainly mistaken for a well-differentiated adenocarcinoma. Since the Brunner gland is submucosal, more tissue depth is needed with endoscopic biopsy, hence indeterminate results.

• Computed Tomography (CT) Scan- Computed tomography with intravenous contrast imaging technique is used. Brunner's gland hyperplasia appears as a duodenal mass that can be differentiated from the pancreatic parenchyma. However, other malignant lesions and Brunner's gland hyperplasia cannot be clearly differentiated with the computed tomography scan (CT).

• Endoscopic Ultrasound (EUS)- It is the best imaging technique for diagnosing submucosal Brunner's gland hyperplasia. Based on endoscopic ultrasound features, Brunner's gland hyperplasia is located in the second and third layers of the duodenum wall with an irregular margin. Cystic areas are also seen within the lesions.

What Is the Differential Diagnosis for Brunners Gland Hyperplasia?

Since the lesion is asymptomatic, providing a diagnosis based on symptoms alone is difficult. The differential diagnosis includes

• Adenomatous Polyps- These are benign growths inside of the tissue and organs.

• Leiomyoma- These are non-cancerous growths that appear in the uterus.

• Gastrointestinal Stromal Tumor- It is a cancer of the small intestine that mainly affects the stomach and small intestine.

• Pancreatic Tumor- Tumor of the pancreas.

What Is the Treatment for Brunners Gland Hyperplasia?

Treatment options for Brunner's gland hyperplasia include endoscopic, laparoscopic, or laparotomy resection of the gland. Endoscopic resection is the most helpful method; however, the anatomical location of the gland limits the endoscopic removal of the lesion. Recurrence of the lesion in Brunner's gland hyperplasia has not been reported.

• Upper Gastrointestinal Endoscopy With Polypectomy (removal of the polyp or growth inside the organ) - It is considered the best treatment option. It is a minimally invasive, cost-effective technique. In addition, the endoscopic polypectomy's success depends on the lesion's location, size, and clinical presentation in the patient.

• Laparoscopic Polypectomy- Laparoscopy is a procedure where abdominal access is made without making a large incision in the skin of the abdomen. It is a minimally invasive technique. Laparoscopic polypectomy is the removal of polyps from Brunner's gland hyperplasia.

• Laparotomy- Laparotomy is the procedure where a surgical incision is made in the abdominal cavity. It is mainly done for large and sessile (immobile and without a stalk) lesions. It is also the treatment of choice where endoscopic removal is impossible and in patients unstable due to excessive bleeding from Brunner's gland hyperplasia.

• Pancreaticoduodenectomy- In rare cases, pancreaticoduodenectomy is the treatment choice. This surgical process involves removing the head of the pancreas, the duodenum, the gall bladder, and the bile duct. It is performed to obtain wide and clear margins of the healthy tissue in cases of suspected malignancy.

Conclusion

Brunner's gland hyperplasia is an incidental endoscopic finding. These rare benign lesions can cause gastrointestinal bleeding and obstructive gastrointestinal symptoms. They rarely show malignant transformation. The best management plan needs a thorough assessment of the patients. Endoscopic resection of the lesion is the preferred treatment choice. Both pre-operative and intra-operative (performed during the course of surgery) assessment is important to set up the treatment plan. An extensive examination of the duodenum intra-operatively by the surgeon reduces the extent of surgery.