Internal-Medicine

56 3: Endocrinology
23. A 19-year-old man has early fatigue and muscle
cramps while playing sports. He is fine when
walking or doing light levels of work. On
examination, he appears well and the muscle
strength in the proximal muscles is normal.
There is no muscle fatigue with repetitive arm
grip exercises. After an exercise stress test, his
serum creatine kinase (CK) is elevated and lactate
level is normal. Which of the following is
the most likely diagnosis?
(A) Gaucher’s disease
(B) Tay-Sachs disease
(C) McArdle’s disease (glycogen storage
disease)
(D) hemochromatosis
(E) myasthenia gravis
24. A 33-year-old man develops severe left flank
pain that radiates to the front inguinal region.
The pain eventually subsides after the passage
of “sand-like” urine. A urinalysis reveals flat
hexagonal plate like crystals (cystine). Which of
the following statements about this condition is
most likely true?
(A) commonest cause of renal stones
(B) stones are radiolucent on x-ray
(C) increased cystine concentration in the
urine
(D) decreased cystine concentration in the
urine
(E) acquired disorder of cystine metabolism
25. A 50-year-old man presents with feeling tired
and unsteady on his feet. He has a poor appetite
and has lost 10 lb. On examination, he appears
cachectic, his heart and lungs are normal, but
his liver span is 18 cm. His lab tests show a
very low magnesium level (0.7 mEq/L). On
further questioning, he reports drinking heavily
since losing his job. Which of the following is
the most likely explanation for his low magnesium
level?
26. A 27-year-old woman presents with feeling
unwell ever since going on a high vitamin diet.
She has dry skin, vomiting, headaches, and
amenorrhea. Her examination and lab data are
positive for hepatomegaly, splenomegaly,
leukopenia, anemia, periosteal changes, sparse
and coarse hair, and increased serum lipids.
Which of the following is the most likely diagnosis?
(A)
(B)
(C)
(D)
(E)
vitamin D intoxication
vitamin D deficiency
vitamin A deficiency
vitamin A intoxication
carotenemia
27. The patient whose hands are shown in Fig. 3–4
is developmentally delayed with a short,
stocky build. Which of the following is the most
likely diagnosis?
(A)
(B)
(C)
(D)
(E)
achondroplastic dwarf
Down syndrome
Klinefelter’s syndrome
pseudohypoparathyroidism
Turner’s syndrome
Figure 3–4.
(A)
(B)
(C)
(D)
(E)
alcoholism
chronic malabsorption
DM
kwashiorkor
hypervitaminosis E
28. Which of the following laboratory values is
consistent with the patient shown in Fig. 3–4?
(A)
(B)
hypercalcemia, hypophosphatemia
hypocalcemia, low PTH