pearljam59
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A 45-year-old woman has the recent onset of shortness of breath. She has had a cough and a 14-kg (30-lb) weight loss over the past 6 months. An x-ray of the chest shows a 4-cm mass in the middle lobe of the right lung. Examination of tissue obtained on biopsy shows a small cell, neuroendocrine lung carcinoma. Which of the following abnormalities is most likely to develop in this patient?
A. Hypocalcemia
B. Hypoglycemia
C. Hyponatremia
D. Polycythemia
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| skyhigh
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C
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| robin082006
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C, ADH secretion
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| ManuNastai
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well... I don't know about that. small cell ca can secrete both ACTH and ADH in the same extent.
what we know for sure is that he has developed a brochobstructive sindrome which in time will develop polycytemia (D) as a compensatory mecanism of hypoxemia.
PS: ADH doesn't do hyponatremia. it's action is on WATER channels and increases the water content of the organism by stimulating the reabsorbtion (anti-diuretic). if there was hyponatremia, due to a possible excretion of Na+ in urine, the Na+ would atract the water in the urine, so the body water would decrease.. this happens in diabetus insipidus which has LOW levels of ADH
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| doc179
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C is the ans ...ADH absorbs more free water and causes dilutional hyponatremia
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| pearljam59
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Hmmm all along I was thinking this was a CARCINOID tumor due to the presence of neuroendocrine cells. So the first thought that jumped in my head was serotonin, but that has nothing to do with the answer choices.
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| pearljam59
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Ohhhh I brought out the BIG Robbins book and read...
"Neoplasms of neuroendocrine cells in the lungh include...carcinoid and the highly aggressive small cell carcinoma of the lung."
So then the patient is secreting ADH which retains water causing a dilutional hyponatremia!
So simple yet I was completely on the wrong track.
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| druas
Forum Elite
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yes C
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| laura81
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if its dilutional Natremia, why not hypocalcemia also....i was thinking to the polycitemia...
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