drstepbystep
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This are very board-like questions. I will realease the explanations tomorrow or when 5 of you give their answers. It will be enriching if you give the rationale for your answers EVEN IF THEY IMPLY GUESSING OR PLAYING WITH THE DISTRACTORS.  /
1. A 42 y-o white man has consulted several physicians for long-standing mild joint pain, large-sized, foul-smelling stools and weight loss. All the physicians have consistently found a heart murmur and lymphadenophaties, but they haven't achieved a diagnosis. He has been receiving antibiotics for one month, with a partial remission of the symptoms. He reports a trip to Colombia prior to the onset of the disease. Which of the following findings are more likely to be observed under optic microscopy of the small intestine?
A. No change or blunting of the mucosal villi.
B. Bacterial inclusions in the mucosal macrophages.
C. Noncaseating granulomas.
D. PAS-positive granuli in the macrophages.
E. Dilation of the submucosal lymphatics
2. A 15-months-old boy is brought to consultation by his grandmother, who hadn’t seen him in a year. Although well fed by his parents, the child has been presenting large, frothy, foul smelling stools and is under the 3rd percentile of weight for his age. He is unable to walk. The examination of the retina reveals a dark pigment. A blood test reveals acanthocytes. What is most likely true about the underlying defect of his disease?
a. It is located in the brush border of the intestinal mucosa.
b. It is explained by an incapacity to break down lactose.
c. It is due to an exaggerated immune response elicited by gliadin
d. It is due to an abnormality in the production of chilomycrons
e. It is related to a protozoan infestation of the duodenum
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Ricardo
Life is what happens to you while you're busy making other plans. (Lennon)
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| Malaysian
Forum Guru
Topics: 28
Posts: 778
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1.B(I have done a very similar Q. to this just last night but I'm not sure what the answer is as I haven't read the answer for it which I will be doing it tonight....if my answer differs I'll change it!!!)
2.D
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| MLF
Forum Elite
Topics: 36
Posts: 386
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!)B - Whipple disease, which has PAS positive macrophages in mucosa. Bug is Tropheryma whippelii.
2)D - This is Abetalipoproteinemia - acanthocytes are prominent and they are basically red cells with spiny projections.
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| mani
Forum Guru
Topics: 104
Posts: 1,403
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agree with answers
1-B
2-D
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| monica76
Forum Senior
Topics: 13
Posts: 151
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yup.. 1. whipples
2. abetalipoproteinemia
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| sanjeevchoubey
Forum Newbie
Topics: 0
Posts: 1
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i think b part is the write answer of this q
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i am medical student .& studing in st andrews,pune
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| drstepbystep
Forum Junior
Topics: 12
Posts: 36
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OK, kids, CONGRATULATIONS. Here are the Kaplan-style discussions: :icon_thumb:
1. A 42 y-o white man has consulted several physicians for long-standing mild joint pain, large-sized, foul-smelling stools and weight loss. All the physicians have consistently found a heart murmur and lymphadenophaties. He has been receiving antibiotics for one month, with a partial remission of the symptoms. He reports a trip to Colombia prior to the onset of the disease. Which of the following findings are more likely to be observed under optic microscopy of the small intestine?
A. No change or blunting of the mucosal villi.
B. Bacterial inclusions in the mucosal macrophages.
C. Noncaseating granulomas.
D. Periodic Acid Shiff-positive granuli in the macrophages.
E. Dilation of the submucosal lymphatics
The correct answer is D.
This patient is most probably suffering Whipple’s disease. Large-sized, foul smelling stools and weight loss are a typical finding in all malabsorption syndromes; however, the clue to the diagnosis is the concept that Whipple’s disease is a SYSTEMIC disease of INFECTIOUS cause. Systemic features found in Whipple’s disease are arthritis, lymphadenopathies and rarely, heart and nervous system involvement (the latter of which was not present in this case). The infectious agent is Tropheryma whippleii and the patients better with antibiotics (usually long-term, as stated in the vignette, but you don’t need to learn this for Step 1). The typical finding in OPTIC MICROSCOPY is macrophages in the intestinal mucosa, showing PAS positive inclusions, which, when further observed by ELECTRON MICROSCOPY turn to be rod-shaped bacteria. (OPTION B)
C
Noncaseating granulomas are observed in Crohn’s disease of the small intestine, which is often complicated by malabsorption. This is a good distractor, since migratory polyarthritis is a common extra-intestinal manifestation; however, lymphadenopathies and heart involvement are not features of inflammatory bowel disease.
A
In Tropical Sprue, the mucosa may be normal, may have unspecific changes or may resemble that seen in celiac sprue: blunting of the mucosal villi with lymphocytic infiltration of the mucosa. Tropical Sprue affects people living in or travelling to the tropics and responds to antibiotics (as in this patient), therefore being suspected to be an infectous disease with an unidentified agent. However, joint and heart involvement are not present.
E
Dilation of intestinal lymphatics can occur primarily in INTESTINAL LYMPHANGIECTASIA or secondary to obstruction of intestinal lymphatics by trauma or neoplasia. Systemic features and response to antibiotics make Whipple’s disease a better diagnosis. Furthermore, lymphatic obstruction leads mainly to the loss of proteins and lymphocytes, with a fairly preserved absorption of fats and carbohydrates, hence presenting with edema and lymphocytopenia, rather than with esteatorrhea (Protein-losing enteropathy)
A 15-months-old boy is brought to consultation by his grandmother, who hadn’t seen him in a year. Although well fed by his parents, the child has been presenting large, frothy, foul smelling stools and is under the 3rd percentile of weight for his age. He is unable to walk. The examination of the retina reveals a dark pigment. A blood test reveals acanthocytes, What is most likely true about the underlying defect of his disease?
a. It is located in the brush border of the intestinal mucosa.
b. It is explained by an incapacity to break down lactose.
c. It is due to an exaggerated immune response elicited by gliadin
d. It is due to an abnormality in the production of chilomycrons
e. It is related to a protozoan infestation of the duodenum
The correct answer is D
This child has ABETALIPOPROTEINEMIA, the autosomal recessive deficit of Beta-lipoprotein. This deficiency leads to the inability to build a kind of chylomicrons and to the laboratorial hallmark of the disease: ACANTHOCYTES, which are spur-shaped red cells (red cells with spins, not exclusive, but characteristic). The other clinical features (not found in the review books for Step 1, but stressed in Robbin’s Pathology and Harrison’s) are ATAXIA and PIGMENTOUS RETINITS. The inability to walk in this boy can be due both to the ataxia or to severe malnutrition, but the findings in the retina are highly suggestive of abetalipoproteinemia, in the context presented.
A -B
Dissacaridases are located in the microvilli of the cells of the small intestine, which, altogether are known as the “brush border”. Lactase defficiency, leading to lactose intolerance is the most common form of dissacaridase defficiency.
C
Gliadin is the component of gluten that elicits the abnormal inmune response in celiac disease (also known as celiac sprue or gluten sensitivity)
E
Giardia lamblia is a protozoan causing malabsorption.
The clue to the answer was identifying at least one of the classical findings in Abetalipoproteinmenia (acanthocytosis would have been enough)
I'll post new questions soon.
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Ricardo
Life is what happens to you while you're busy making other plans. (Lennon)
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