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John M Petersen

Publications and source records attributed to John M Petersen.

4 recordsLinked to original sources

Tropical pancreatitis.

Tropical pancreatitis is an uncommon cause of acute, and often chronic, relapsing pancreatitis. Patients present with abdominal pain, weight loss, pancreatic calcifications, and glucose intolerance or diabetes mellitus. Etiologies include a protein-calorie malnourished state, a variety of exogenous food toxins, pancreatic duct anomalies, and a possible genetic predisposition. Chronic cyanide exposure from the diet may contribute to this disease, seen often in India, Asia, and Africa. The pancreatic duct of these patients often is markedly dilated, and may contain stones, with or without strictures. The risk of ductal carcinoma with this disease is accentuated. Treatment may be frustrating, and may include pancreatic enzymes, duct manipulations at endoscopic retrograde cholangiopancreatography, octreotide, celiac axis blocks for pain control, or surgery via drainage and/or resection.

Adult↗

Role of endoscopic ultrasound (EUS) and EUS-guided fine needle aspiration in the diagnosis and treatment of cystic lesions of the pancreas.

INTRODUCTION AND AIMS: Cystic neoplasms of the pancreas may be inadvertently treated as benign pseudocysts in clinical practice, often without the use of cytology, cyst tumor markers, or histopathology. We assessed the utility of EUS-guided fine-needle aspiration (EUS-FNA) to assist in the diagnosis and management of pancreatic cysts. METHODOLOGY: All patients who had pancreatic cysts detected by EUS over a 24-month period were analyzed. Preoperative diagnosis was derived from an algorithm combining clinical history and endosonographic features. In selected cases, EUS-FNA was performed and cyst fluid aspirates were analyzed. Surgical specimens served as diagnostic standard. RESULTS: A total of 43 patients with pancreatic cysts underwent 45 EUS examinations. Surgical specimens were obtained from 9 patients (mucinous cystadenocarcinoma, 3; adenocarcinoma, 3; pancreatic endocrine tumor, 2; and benign cyst, 1); diagnostic EUS correctly predicted malignant cysts in 8/9 (88.9%). One case inaccurately interpreted by EUS as cystic neoplasm turned out to be a benign cyst on resection. Twenty-one patients underwent EUS-FNA. The cytologic interpretation was adenocarcinoma in 9.5% (2/21); suspicious for malignancy or atypical cells in 19.0% (4/21); benign in 66.6% (14/21); and insufficient cells in 4.8% (1/21). CONCLUSION: The information gathered from clinical history and EUS, complemented by fluid analysis after EUS-guided FNA, predicts neoplastic pancreatic cysts and assists in decision-making for medical or surgical approach.

Algorithms↗

Chronic pancreatitis and maldigestion.

Patients with chronic pancreatitis may suffer from maldigestion and malnutrition. Longstanding inflammation and fibrosis in the gland can destroy exocrine tissue, leading to inadequate delivery of digestive enzymes to the duodenum in the prandial and postprandial period and subsequent maldigestion. Maldigestion is augmented by inadequate bicarbonate delivery to the duodenum, with secondary inactivation of enzymes and bile acids by gastric acid. Abdominal pain, sitophobia, nausea, vomiting, postprandial satiety, and on-going alcohol abuse may contribute to poor oral intake. Gastric dysmotility and mechanical gastric outlet obstruction from fibrosis in the pancreatic head may contribute to malnutrition and clinical decline. Patients with chronic pancreatitis may at times experience profound steatorrhea and weight loss. In this article, we examine the natural history of exocrine insufficiency in chronic pancreatitis, outline the important nutritional issues in these patients, review the methods of diagnosis of maldigestion, and discuss the approach to therapy.

Chronic Disease↗