Page 811 - Cote clinical veterinary advisor dogs and cats 4th

383.e2 Gastrointestinal Endocrine Disease

Gastrointestinal Endocrine Disease Client Education
Sheet
VetBooks.ir Advanced or Confirmatory Testing
PHYSICAL EXAM FINDINGS
BASIC INFORMATION
• Gastrinoma: weight loss, pale mucous • Definitive diagnosis occurs by histopathology
Definition membranes, abdominal pain, melena, fever, and immunostaining of the identified masses
Gastrointestinal (GI) endocrine disease results or dehydration and any metastatic tissue. Ancillary testing
from rare tumors of hormone-producing cells • Glucagonoma: skin lesions and ulceration may help to define the clinical syndrome.
in the GI tract. They are called amine precursor especially at the mucocutaneous junctions • Abdominal CT may be more likely than
uptake decarboxylase (APUD) tumors. and footpads, decreased muscle mass or ultrasound to identify a mass.
weight loss • Gastrinoma
Synonyms • Carcinoid tumors: no specific findings; weight ○ Serum gastrin levels are elevated, but this
• Gastrinoma (Zollinger-Ellison syndrome, loss or abdominal pain if GI obstruction can occur with other diseases or during use
delta-cell tumor) • Pancreatic polypeptidoma: usually no specific of drugs that inhibit gastric acid secretion.
• Glucagonoma (alpha-cell tumor) findings; possible abdominal pain ○ GI endoscopy may reveal esophagitis,
• Pancreatic polypeptidoma bleeding, or gastric ulceration.
• Carcinoid tumor Etiology and Pathophysiology • Glucagonoma
• Insulinoma (addressed elsewhere [p. 552]) • Specialized endocrine cells are located ○ Histopathology of ulcerative skin lesions
throughout the GI system. reveals necrolytic migratory erythema,
Epidemiology • Tumors of the endocrine cells cause unregu- although this is not a specific finding
SPECIES, AGE, SEX lated hypersecretion of hormones. (e.g., liver disease can cause same finding).
• Gastrinoma: middle- to older-aged dogs • Elevated hormone concentrations result in ○ Elevated serum glucagon levels (1.5-15
(mean age, 8 years) and cats processes (e.g., hypersecretion of gastric acid times higher than the reference range);
• Glucagonoma: middle- to older-aged dogs due to a gastrinoma) that cause the clinical assay may not be available.
and one cat (6 years old, male, neutered, signs. ○ Measurement of plasma amino acids may
domestic shorthair) • Some tumors do not produce hormones show lower levels of arginine, histidine,
• Carcinoid tumors: middle- to older-aged but cause clinical signs by their physical and lysine.
dogs and cats presence.
• Pancreatic polypeptidoma: two dogs (7-year- TREATMENT
old, female, spayed [FS] cocker spaniel, DIAGNOSIS
14-year-old, FS golden retriever) Treatment Overview
Diagnostic Overview Definitive treatment involves removal of the
ASSOCIATED DISORDERS Clinical signs are often nonspecific and slowly primary tumor. Identifiable metastatic tissue
• Gastrinoma: GI ulceration progressive. Abnormalities may not be noticed should be removed or debulked as it may be
• Glucagonoma: superficial necrolytic derma- until the disease is advanced. Clinical signs functional. Associated clinical signs may be
titis and diabetes mellitus should be evaluated with biochemical testing to managed symptomatically.
rule out more common diseases. Final diagnosis
Clinical Presentation is usually achieved through a combination of Acute General Treatment
DISEASE FORMS/SUBTYPES imaging, hormone measurement, histopathol- • Fluid and electrolyte therapy, as needed
• Gastrinoma: hypersecretion of gastrin from ogy, and immunostaining of the tumor. • Parenteral nutrition, if necessary
a pancreatic tumor • Gastrinoma: aggressive treatment for gastric
• Glucagonoma: hypersecretion of glucagon Differential Diagnosis hyperacidity and ulceration (p. 380); blood
from a pancreatic tumor Depends on the clinical signs. product transfusion if necessary (p. 1169)
• Carcinoid tumors: hypersecretion of sero- • Vomiting (pp. 1042 and 1294)
tonin from a tumor that may be located in a • Diarrhea (pp. 262 and 1213) Chronic Treatment
variety of GI organs; most are nonfunctional • Abdominal pain (p. 21) • Surgical removal of tumor and identifiable
• Pancreatic polypeptidoma: hypersecretion • Weight loss (pp. 1047 and 1295) metastases is preferred; severe GI ulcers due
of pancreatic polypeptide from a pancreatic • Uncontrolled diabetes mellitus (p. 251) to gastrinoma may be resected.
tumor • Ulcerative and erosive skin lesions (p. 952) • Gastrinoma
○ Gastric and esophageal protectants
HISTORY, CHIEF COMPLAINT Initial Database ■ Proton pump inhibitor (omeprazole
• Gastrinoma: vomiting, diarrhea, weight loss, • CBC, biochemical profile, and urinalysis 0.7-1.5 mg/kg q 24h)
abdominal pain, gastric outflow obstruction ○ Gastrinoma: normal, or may see anemia, ■ Sucralfate suspension (0.5-1 g q 8h,
from gastric mucosal hypertrophy, or GI leukocytosis +/− left shift, and hypopro- dogs; 0.25-0.5 g q 8h, cats)
bleeding teinemia if GI ulceration; elevation of liver ○ Somatostatin inhibitor (octreotide 2-
• Glucagonoma: nonhealing skin lesions and enzymes if metastatic disease; hypokale- 20 mcg SQ q 8h) may be tried.
ulcers (i.e., superficial necrolytic dermatitis mia, hypochloremia, hyponatremia, and • Glucagonoma
[p. 952]), polyuria, polydipsia, weight metabolic acidosis if severe vomiting ○ Amino acid supplementation:
loss, or uncontrolled diabetes mellitus ○ Glucagonoma: hyperglycemia, glucosuria, ■ Aminosyn 10% solution without
(p. 251) and elevated liver enzymes commonly electrolytes (25 mL/kg IV over 8 hours
• Carcinoid tumors: nonspecific or no clinical seen through a central line once per week
signs; may have abdominal pain, weight ○ Carcinoid tumors and pancreatic polypep- or as required to control clinical signs)
loss, anorexia, vomiting, or other signs of tidoma: usually no specific abnormalities ■ Egg yolk or high-protein supplementa-
GI obstruction • Thoracic and abdominal radiographs: usually tion powder (less effective)
• Pancreatic polypeptidoma: usually no clinical normal ○ Octreotide (see above)
signs; may have abdominal pain, chronic • Abdominal ultrasound: may reveal a pan- ○ Aggressive insulin therapy for resistant
vomiting, or diarrhea creatic mass or metastatic lesions. diabetes mellitus (p. 251)
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