Insulinoma - Pancreatic cancers
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An insulinoma is a rare pancreatic β-cell tumor that hypersecretes insulin. The main symptom is fasting hypoglycemia. Diagnosis is by a 48- or 72-h fast with measurement of glucose and insulin levels, followed by endoscopic ultrasound. Treatment is surgery when possible. Drugs that block insulin secretion (eg, diazoxide, octreotide, Ca channel blockers, β-blockers, phenytoin) are used for patients not responding to surgery.
Of all insulinomas, 80% are single and may be curatively resected if identified. Only 10% of insulinomas are malignant. Insulinoma occurs in 1/250,000 at a median age of 50 yr, except in multiple endocrine neoplasia (MEN) type I (about 10% of insulinomas), when it occurs in the 20s. Insulinomas associated with MEN type I are more likely to be multiple.
Surreptitious administration of exogenous insulin can cause episodic hypoglycemia mimicking insulinoma.
Zollinger-Ellison Syndrom - Pancreatic cancers
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Zollinger-Ellison Syndrom -(Z-E Syndrome; Gastrinoma)
Zollinger-Ellison syndrome is caused by a gastrin-producing tumor usually located in the pancreas or the duodenal wall. Gastric acid hypersecretion and peptic ulceration result. Diagnosis is by measuring serum gastrin levels. Treatment is proton pump inhibitors and surgical removal.
Gastrinomas occur in the pancreas or duodenal wall 80 to 90% of the time. The remainder occur in the splenic hilum, mesentery, stomach, lymph node, or ovary. About 50% of patients have multiple tumors. Gastrinomas usually are small (< 1 cm in diameter) and grow slowly. About 50% are malignant. About 40 to 60% of patients with gastrinoma have multiple endocrine neoplasia.
Vipoma - Pancreatic cancers
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A vipoma is a non-β pancreatic islet cell tumor secreting vasoactive intestinal peptide (VIP), resulting in a syndrome of watery diarrhea, hypokalemia, and achlorhydria (WDHA syndrome). Diagnosis is by serum VIP levels, and tumor is localized with CT and endoscopic ultrasound. Treatment is surgical resection.
Of these tumors, 50 to 75% are malignant, and some may be quite large (7 cm) at diagnosis. In about 6%, vipoma occurs as part of multiple endocrine neoplasia.
Glucagonoma - Pancreatic cancers
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A glucagonoma is a pancreatic α-cell tumor that secretes glucagon, producing hyperglycemia and a characteristic skin rash. Diagnosis is by elevated glucagon levels and imaging studies. Tumor is localized with CT and endoscopic ultrasound. Treatment is surgical resection.
Glucagonomas are very rare but similar to other islet cell tumors in that the primary and metastatic lesions are slow-growing: 15-yr survival is common. Eighty percent of glucagonomas are malignant. The average age at symptom onset is 50 yr; 80% of patients are women. A few patients have multiple endocrine neoplasia type I.
Gastrointestinal stromal tumors
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Gastrointestinal stromal tumors (GIST) are tumors of the GI tract derived from mesenchymal precursor cells in the gut wall. They result from mutations of a growth factor receptor gene, C-KIT. Some are caused by previous radiation therapy to the abdomen for other tumors.
Tumors are slow growing, and malignant potential varies from minimal to significant. Most (60 to 70%) occur in the stomach, 20 to 25% in the small bowel, and a small number in the esophagus, colon, and rectum. Average age at presentation is 50 to 60.
Small-bowel tumors
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Small-bowel tumors account for 1 to 5% of GI tumors.
Benign tumors include leiomyomas, lipomas, neurofibromas, and fibromas. All may cause abdominal distention, pain, bleeding, diarrhea or, if obstruction develops, vomiting. Polyps are not as common as in the colon.
Polyps of the Colon and rectum
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An intestinal polyp is any mass of tissue that arises from the bowel wall and protrudes into the lumen. Most are asymptomatic except for minor bleeding, which is usually occult. The main concern is malignant transformation; most colon cancers arise in a previously benign adenomatous polyp. Diagnosis is by endoscopy. Treatment is endoscopic removal.
Polyps may be sessile or pedunculated and vary considerably in size. Incidence of polyps ranges from 7 to 50%; the higher figure includes very small polyps (usually hyperplastic polyps or adenomas) found at autopsy. Polyps, often multiple, occur most commonly in the rectum and sigmoid and decrease in frequency toward the cecum. Multiple polyps may represent familial adenomatous polyposis. About 25% of patients with cancer of the large bowel also have satellite adenomatous polyps.
Adenomatous (neoplastic) polyps are of greatest concern. Such lesions are classified histologically as tubular adenomas, tubulovillous adenomas (villoglandular polyps), or villous adenomas. The likelihood of malignancy in an adenomatous polyp at the time of discovery is related to size, histologic type, and degree of dysplasia; a 1.5-cm tubular adenoma has a 2% risk of containing a malignancy, vs. 35% risk in 3-cm villous adenomas.
Familial adenomatous polyposis
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Familial adenomatous polyposis is a hereditary disorder causing numerous colonic polyps and resulting in colon carcinoma by age 40. Patients are usually asymptomatic but may have heme-positive stool. Diagnosis is by colonoscopy and genetic testing. Treatment is colectomy.
Familial adenomatous polyposis (FAP) is an autosomal dominant disease in which ≥ 100 adenomatous polyps carpet the colon and rectum. The disorder occurs in 1 in 8,000 to 14,000 people. Polyps are present in 50% of patients by age 15, and 95% by 35. Malignancy develops before age 40 in nearly all untreated patients.
Patients also can develop various extracolonic manifestations (previously termed Gardner’s syndrome), both benign and malignant. Benign manifestations include desmoid tumors, osteomas of the skull or mandible, sebaceous cysts, and adenomas in other parts of the GI tract. Patients are at increased risk for malignancy in the duodenum (5 to 11%), pancreas (2%), thyroid (2%), brain (medulloblastoma in < 1%), and liver (hepatoblastoma in 0.7% of children < 5).
Stomach cancer
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Etiology of stomach cancer is multifactorial, but Helicobacter pylori plays a significant role. Symptoms include early satiety, obstruction, and bleeding but tend to occur late in the disease. Diagnosis is by endoscopy, followed by CT and endoscopic ultrasound for staging. Treatment is mainly surgery; chemotherapy may provide a temporary response. Long-term survival is poor except for those with local disease.
Stomach cancer accounts for about 21,000 cases and 12,000 deaths in the US annually. Gastric adenocarcinoma accounts for 95% of malignant tumors of the stomach; less common are localized gastric lymphomas and leiomyosarcomas. Stomach cancer is the 2nd most common cancer worldwide, but the incidence varies widely; it is extremely high in Japan, Chile, and Iceland. In the US, incidence has declined in recent decades to the 7th most common cause of death from cancer. In the US, it is most common in blacks, Hispanics, and American Indians. Its incidence increases with age; > 75% of patients are > 50 yr.
Esophageal tumor
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The most common malignant esophageal tumor is squamous cell carcinoma, followed by adenocarcinoma. Symptoms are progressive dysphagia and weight loss. Diagnosis is by endoscopy, followed by CT and endoscopic ultrasound for staging. Treatment varies with stage and generally includes surgery with or without chemotherapy and radiation. Long-term survival is poor except for those with local disease.
Esophageal cancer accounts for about 13,500 cases and 12,500 deaths in the US annually.
Penile and Urethral Carcinoma
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Penile and urethral carcinomas are rare. Most physicians will never be involved in the management of such a case. Because of their rarity, delay in diagnosis secondary to both patient and physician factors are a constant threat. Any lesion of the penis that cannot be definitively diagnosed must be considered cancer until otherwise proven. Steps must then be taken to establish a definitive diagnosis or the patient should be referred to an appropriate consultant. Urethral cancer in men frequently masquerades as a urethral stricture.
The annual meeting of the American Urological Association was held in San Antonio, Texas, May 21-26, 2005. At this meeting, a number of papers were presented on these topics.
Study children and cellphones, US experts advise
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Researchers should study more children and pregnant women in trying to figure out if cell phones or other wireless devices could damage health, the U.S. National Research Council advised on Thursday.
A few studies have indicated a possible link between mobile telephone use and brain tumors, although far more show no connection. But because wireless devices have become almost ubiquitous, researchers wants to ensure their safety.
The U.S. Food and Drug Administration asked the National Research Council to recommend some future lines of study. The Council, which advises Congress and the federal government on scientific matters, held a meeting of experts including engineers and biologists and has now released the full report.
Diabetes narrows gender gap in heart disease death
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Eighteen years of follow-up shows that men are twice as likely to die from heart disease as women. However, this gender gap is markedly reduced when only patients with diabetes are considered.
The reason? Diabetes is a stronger risk factor for heart disease death in women than in men.
In the European Heart Journal, Dr. Ane Cecilie Dale, of the Norwegian University of Science and Technology in Trondheim, and colleagues report data from HUNT 1, a large study in which all adults of Trendelag County, Norway, were invited to participate.
High BP-obesity link varies among Africans: study
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Excess fat may not be the only factor that increases the risk of high blood pressure (hypertension) among obese people of African descent, according to an international research team.
They found that while blood pressure increased with body weight in 13 different groups of Africans or people of African heritage living in the UK, United States, or the Caribbean, the degree to which blood pressure rose with body weight varied among the groups.
Evidence is strong that an increase in blood pressure as body mass index (BMI) rises is universal across the world’s populations, but there has been some research suggesting that the relationship might vary “in populations at the extremes of the BMI distribution,” Dr. Francesco P. Cappuccio of Warwick Medical School in Coventry, UK, and colleagues explain in the medical journal, Epidemiology.
Post-concussion depression more than emotional
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Post-concussion symptoms of depression may stem from an underlying neurological abnormality caused by the concussion, results of a Canadian study suggest.
Depression after a blow to the head may not simply be the individual’s emotional or psychological reaction to the injury and their subsequent loss of playing time, as is commonly thought, investigators note in the medical journal, Archives of General Psychiatry.
“It seems there is a cerebral dysfunction caused by the injury,” Dr. Alain Ptito, of the Montreal Neurological Institute and Hospital at McGill University in Quebec, told Reuters Health. The injury manifests itself as symptoms of depression, he added.
