What Is an Islet Cell Tumor?
Tumors of pancreatic islet cell tumor are also called islet cell adenoma.
Islet cell tumor
Basic overview of islet cell tumor
- Tumors of pancreatic islet cell tumor are also called islet cell adenoma.
- A tumor that develops in islet cells.
- Pancreatic islet cell tumors are divided into two categories, functional and non-functional. Functional islet cell tumors are mainly insulinomas, formed by beta cells, which are rarely seen clinically. According to foreign statistics, the incidence is (3 ~ 4) / million.
Islet cell tumor symptoms
- The most common sites are pancreatic tail, body, and head, and ectopic pancreas can also occur. Common in 20 to 50 years old.
Clinical manifestations of islet cell tumor
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Islet cell tumor pathology
- Pathological changes: (1) Macroscopic view: Most tumors are single, small in size, about 1cm to 5cm or larger, can weigh up to 500g, round or oval, with a clear state, complete or incomplete capsule, light gray Red or dark red, soft and homogeneous, secondary to fibrous tissue hyperplasia, calcification, starch or mucus-like degeneration, and cystic changes; (2) Microscopically: tumor cells are arranged in various forms, and some are arranged in islands ( Like giant islets) or clumps, and some of them are cerebral gyrus, beam-like, cord-like, acinar, and glandular or chrysanthemum-like structures. They can also be solid, diffuse, irregularly arranged, and various The structures are mixed or arranged individually. Capillary blood vessels are present during this period, and it can be seen how many collagen fibers separate the tumor tissue, and there may be secondary changes such as mucus, amyloidosis, and calcification. Tumor cells resemble pancreatic islet cells, with small round, short spindle or polygonal shapes, with more consistent morphology. The nucleus is round or oval, short spindle, fine chromatin, small nucleoli visible, rare mitosis, and occasionally giant cell.
Islet cell tumor diagnosis
- Insulinoma secretes excessive amounts of insulin into the blood, causing a series of symptoms, mainly hypoglycemia. Patients may present with a paroxysmal hypoglycemia coma, which will damage brain tissue and cause disturbance of consciousness and mental disorders. The main clinical manifestations are hypoglycemia syndrome and elevated plasma insulin levels. Hypoglycemia episodes often become frequent with the course of the disease, the duration of the episodes is prolonged, and the severity of the episodes is often accompanied by gradual obesity of the body and decreased memory and response. Because the clinical manifestations of insulinomas are complex and diverse, cases are rare and often misdiagnosed. Statistics abroad show that the average time from onset to diagnosis is 3 years.
Qualitative diagnosis of islet cell tumor
- The qualitative diagnosis of insulinoma relies on the Whipple triad and the determination of plasma insulin levels. The first step in diagnosing insulinoma is to determine if the symptoms are caused by hypoglycemia. The classic Whipple triad is still of great significance for diagnosis, that is, the onset of symptoms on an empty stomach; the blood glucose level on an empty stomach or onset is <2.78mmol / L (50mg / dl); eating or intravenous bolus glucose can quickly relieve the symptoms. More than 90% of patients can be correctly diagnosed based on the Whipple triad.
Islet cell tumor localization diagnosis
- Currently, the main challenge in the diagnosis of insulinoma is localization. More than 80% of insulinomas are less than 2 cm in diameter and generally do not cause changes in the outline of the pancreas. Conventional morphological localization methods such as ultrasound, CT, and magnetic resonance (MRI) are difficult to find. The diagnosis of insulinoma localization is generally divided into two categories: morphological localization and functional localization. The main morphological locations are: (1) abdominal ultrasound, the overall diagnosis rate is not high, about 35.1%. The reason is that the pancreas is deep and susceptible to intestinal gas, abdominal fat and spleen. (2) The accuracy of localized CT scan is relatively low, ranging from 40.0% to 67.9%; while the positive rate of spiral CT thin scan and arterial enhanced CT scan is above 90%. (3) Other morphological examinations include MRI, color Doppler endoscopy (ECDUS), laparoscopic ultrasound, and intraoperative ultrasound (IOS). Among them, ECDUS and laparoscopic ultrasound are new technologies for localization of insulin tumors in recent years. It is reported that its detection rate is higher than that of CT and abdominal ultrasound. Intraoperative ultrasound can effectively find tumors that cannot be touched during the operation, such as small tumors in the deep part of the head of the pancreas and the uncinate process. This improves the accuracy of intraoperative positioning and reduces blindness.
- Although islet cell tumors are rare in the clinic, their qualitative diagnosis is not difficult. With the development of imaging, the level of localized diagnosis of islet cell tumors has also increased. The diagnosis is clear and the prognosis of most patients with surgical treatment is good.
Islet Cell Tumor Therapy
- The treatment is mainly to remove the tumor by surgery. If the tumor is not found or the tumor has metastasized by surgical exploration, drug treatment is feasible, such as metformin for gastrinoma, meclizine for insulinoma, and somatostatin (SMS- 201 995) for glucagon tumors, adriamycin for somatostatin tumors, etc. 5-Fluorouracil, azolidamine or streptozotocin can also be used for the medical treatment of islet cell tumors.