What is a gastrinoma
Gastrinomas are rare endocrine tumors and commonly present with severe recurrent peptic ulcer disease. More than 60% of gastrinomas are cancerous and the tumor eventually spreads to the liver and other parts of the body.
How are gastrinomas diagnosed?
A diagnosis of a gastrinoma should be considered in a patient with peptic ulcers that recur frequently and are resistant to treatment. A biochemical study to measure the level of gastrin and its response to a hormone called secretin is utilized to make the diagnosis.
Once a diagnosis is made, localizing the tumor is important. Most gastrinomas are small lesions and therefore, localizing the tumor may be difficult. Some of the tests that are performed to localize the tumor include a CT scan, octreotide scan and MRI and an endoscopic ultrasound.
An experienced surgeon will detect these tumors at surgery even when they are not visible on preoperative imaging tests.
How are gastrinomas treated?
Treatment of choice for gastrinoma is to remove the surgically where possible. Peptic ulcers must be aggressively treated and controlled prior to surgery. The type of surgery for gastrinomas depends on the location of the tumor. Since these tumors may frequently occur at more than one spot in the pancreas and the surrounding tissues more than one procedure may be required. The following operative procedures may be utilized to treat gastrinomas.
Other islet cell tumors of the pancreas
- Enucleation: Many small gastrinomas in the pancreas may be treated by enucleation alone. This is a procedure of choice for patients that have small tumors (less than 1cm) where the tumor is located on the surface of the pancreas.
- Resection of the pancreas: in patients with large tumors a distal pancreatectomy or a Whipple operation may be indicated depending on where the tumor is located in the pancreas.
- Duodenal exploration: Gastrinomas often occur in the wall of the duodenum (first part of the intestine) and therefore opening duodenum and carefully feeling it to remove any tumors in this area is important.
- Lymph nodes: In some patients the tumor may be located in the lymph glands outside the pancreas therefore careful palpation and removal of these glands is important at the time of surgery
Other neuroendocrine tumors such as glucagonoma, VIPoma and somastatinoma are extremely uncommon tumors. These tumors are malignant in the vast majority of patients and may present as large tumors at the time of diagnosis. Up to 70% of patients have evidence of spread of the tumor at the time of the diagnosis? Aggressive surgical removal of as much tumor as possible is often indicated to relieve some of the severe symptoms that these tumors may cause because of secretion of hormones from these tumors.