Metabolic syndrome or Syndrome X | Renal, endocrine and reproductive system | Pathology

The WHO defines metabolic syndrome as high insulin levels along with any two of the following - abdominal obesity (increased waist circumference, BMI > 30), dyslipidemia ( triglycerides > 150 mg/dl, HDL < 35 mg/dl in males and < 39 mg/dl in females), hypertension and microalbuminuria. Some organizations also use a fasting plasma glucose > or = 110 mg/dl, insulin resistance and impaired glucose tolerance as criteria. Metabolic syndrome is associated with increased risk of type 2 DM, cardiovascular disease and mortality. Physical inactivity, cigarette smoking, family history of premature CAD, obesity and diets high in carbohydrates and fats are risk factors. It is a proinflammatory and prothrombotic condition. CRP or C reactive protein may be elevated. Weight reduction, increasing physical activity, use of drugs like metformin or thiazolidinediones to increase insulin sensitivity, low dose aspirin and optimal management of dyslipidemias and HT are recommended to treat metabolic syndrome. 3. Islet cell tumors: They are neuroendocrine tumors and may be functional or non-functional tumors. Functional tumors are symptomatic from the hormones produced by them like insulin, glucagon , somatostatin etc while non-functional tumors do not produce hormones and hence, present at a later stage. Cushing’s syndrome due to increased ACTH secretion may be seen.

Common islet cell tumors

Type	Characteristics
Insulinoma	Most common, present with hypoglycemia, high levels of insulin and C peptide, 10% are malignant, 10% are multiple, associated with MEN 1
Gastrinoma	Cause Zollinger Ellison syndrome with multiple peptic ulcers, diarrhea, increased gastric acid secretion, raised serum gastrin levels, high basal gastric output, most found in “gastrinoma triangle” bounded by third part of the duodenum, neck of the pancreas and porta hepatis. Some are extra-pancreatic, in duodenum e.g., most are malignant, associated with MEN 1.
Glucagonoma	Most are malignant, cause non-ketogenic DM, migrating, necrolytic rash, stomatitis, diarrhea, venous thrombosis
VIPomas	Cause watery diarrhea, hypokalemia, achlorhydria (Verner-Morrison syndrome), most are intrapancreatic, others are found in adrenal medulla or sympathetic chain, can be benign or malignant
Somatostatinoma	Rare, slow-growing, cause gallstones, DM and steatorrhea, may occur in pancreas or duodenum, may be seen in neurofibromatosis

Transabdominal ultrasound is less sensitive in detecting islet cell tumors. Endoscopic and intraoperative ultrasound gives better results. CT scan with contrast is the preferred investigation for diagnosing islet cell tumors. MRI can detect very small tumors as well. ERCP helps to detect tumors blocking the pancreatic ducts. Somatostatin receptor positive tumors can be detected by scintigraphy with radiolabeled somatostatin analogue like pentetreotide. Chromogranin A may be elevated in some tumors. Treatment is with enucleation if the tumor is located to the pancreas, pancreatoduodenectomy or Whipple procedure, distal pancreatectomy, gastrectomy, radiofrequency ablation, cryosurgical ablation, chemotherapy and chemoembolization. Somatostatin analogues like octreotide and lanreotide can control tumor growth. Interferon alpha, everolimus and sunitinib are other agents used in therapy.