LWBK1006-25 LWW-Govindan-Review December 12, 2011 19:21
Chapter 25•Cancer of the Endocrine System 363of malignancy. The diagnosis is based on measuring catecholamines and
metabolites in the serum and/or urine. Mutated RET proto-oncogene has
been associated with bilateral pheochromocytomas, but it has not been
associated with extra-adrenal pheochromocytoma.Answer 25.32. The answer is E.
Only limited evidence from retrospective reviews suggested improved
disease-free survival with adjuvant mitotane therapy. Mitotane is asso-
ciated with a wide range of side effects, especially gastrointestinal and
neurologic symptoms. Mitotane levels must be followed closely to guide
therapy.Answer 25.33. The answer is B.
Insulinomas are usually benign, with only 5% to 10% of cases being
malignant. Documentation of metastasis is the only definitive way to diag-
nose malignant disease.Answer 25.34. The answer is D.
Secretory diarrhea is commonly associated with all the listed hormones
except insulin.Answer 25.35. The answer is B.
The percentage of tumors of the endocrine pancreas that are malignant
ranges from 10% for insulinoma, to 50% for glucagonoma, and to at
least 65% for gastrinoma.Answer 25.36. The answer is B.
Papillary thyroid carcinomas are more common in women than men and
the median age at diagnosis is 40 and 41 years. Orphan Annie nuclei
are a characteristic histologic feature of papillary thyroid carcinomas.
The prognosis for follicular variant papillary thyroid cancer is similar to
papillary thyroid carcinomas.Answer 25.37. The answer is D.
Thyroid nodules less than 1 cm in size are not routinely biopsied; however,
there are specific situations where a biopsy may be indicated. Patients with
family history of thyroid cancer, neck irradiation, and nodules that are
positive on the PET scan are all indication for biopsy. A normal TSH level
is not indicative of malignancy.Answer 25.38. The answer is C.
Thyroid lymphomas are rare disease accounting for 1% of all lymphomas
and the vast majority is non-Hodgkin’s type. There is a female predomi-
nance with this disease and it is usually associated with hypothyroidism,
not hyperthyroidism.