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Gastrointestinal ` gastrointestinal—PatHology Gastrointestinal ` gastrointestinal—PatHology seCtion iii 381
Malabsorption Can cause diarrhea, steatorrhea, weight loss, weakness, vitamin and mineral deficiencies. Screen for
syndromes fecal fat (eg, Sudan stain).
Celiac disease Gluten-sensitive enteropathy, celiac sprue. mucosal absorption primarily affects distal
Autoimmune-mediated intolerance of duodenum and/or proximal jejunum.
A
gliadin (gluten protein found in wheat) d-xylose test: passively absorbed in proximal
malabsorption and steatorrhea. Associated small intestine; blood and urine levels with
with HLA-DQ2, HLA-DQ8, northern mucosa defects or bacterial overgrowth,
European descent, dermatitis herpetiformis, normal in pancreatic insufficiency.
bone density. Treatment: gluten-free diet.
Findings: IgA anti-tissue transglutaminase
(IgA tTG), anti-endomysial, anti-deamidated
gliadin peptide antibodies; villous atrophy,
crypt hyperplasia A , and intraepithelial
lymphocytosis. Moderately risk of
malignancy (eg, T-cell lymphoma).
Lactose intolerance Lactase deficiency. Normal-appearing villi, Lactose hydrogen breath test: ⊕ for lactose
except when 2° to injury at tips of villi (eg, viral malabsorption if post-lactose breath hydrogen
enteritis). Osmotic diarrhea with stool pH value rises > 20 ppm compared with baseline.
(colonic bacteria ferment lactose).
Pancreatic Due to chronic pancreatitis, cystic fibrosis, duodenal bicarbonate (and pH) and fecal
insufficiency obstructing cancer. Causes malabsorption of elastase.
fat and fat-soluble vitamins (A, D, E, K) as well
as vitamin B .
12
Tropical sprue Similar findings as celiac sprue (affects small mucosal absorption affecting duodenum and
bowel), but responds to antibiotics. Cause is jejunum but can involve ileum with time.
unknown, but seen in residents of or recent Associated with megaloblastic anemia due to
visitors to tropics. folate deficiency and, later, B deficiency.
12
Whipple disease Infection with Tropheryma whipplei PAS the foamy Whipped cream in a CAN.
(intracellular gram ⊕); PAS ⊕ foamy
B
macrophages in intestinal lamina propria
B , mesenteric nodes. Cardiac symptoms,
Arthralgias, and Neurologic symptoms are
common. Diarrhea/steatorrhea occur later in
disease course. Most common in older men.
FAS1_2019_09-Gastrointestinal.indd 381 11/7/19 4:42 PM
