Devita, Hellman, and Rosenberg's Cancer

LWBK1006-36 LWW-Govindan-Review November 24, 2011 7:39

Chapter 36•Benign and Malignant Mesothelioma 485

ANSWERS

Answer 36.1. The answer is A.

Epithelial is the most common subtype of malignant mesotheliomas, com-

prising approximately 50% to 60% of cases. Biphasic and sarcomatoid

mesotheliomas are less frequent and the uncommon tumors that cannot

be categorized morphologically are called poorly differentiated.

Answer 36.2. The answer is D.

Mesothelioma cells are diffusely positive for pankeratin, keratin 5/6, cal-

retinin, andWT1.CEA, a nonspecific marker, Moc-31, which is com-

monly seen in adenocarcinomas, and TTF-1, which is seen in primary

tumors of the lung and thyroid, are negative in mesotheliomas.

Answer 36.3. The answer is C.

The established poor prognostic factors in malignant mesothelioma are

poor performance status, male gender, anemia, thrombocytosis, leukocy-

tosis, elevated LDH, and nonepithelial histology including sarcomatoid

and biphasic subtypes.

Answer 36.4. The answer is A.

Locally advanced and technically unresectable tumor (T4) is defined by

a tumor involving all the ipsilateral pleural surfaces and extension of the

tumor to the peritoneum, contralateral pleura, mediastinal organs, spine,

chest wall, or internal surface of the pericardium with or without effusion.

Involvement of the endothoracic fascia describes a locally advanced but

potentially resectable disease.

Answer 36.5. The answer is B.

Extension of the tumor to the underlying lung parenchyma and involve-

ment of an ipsilateral bronchopulmonary or hilar lymph node make the

tumor T2 and N1, respectively. T2N1M0 represents a stage III disease.

Answer 36.6. The answer is C.

Solitary FTPs are usually benign, with the malignant variant present in

approximately 10% of cases. The benign variant, however, may relapse

with malignant features. Benign FTPs are associated with clubbing and

osteoarthropathy in 20% to 50% of cases but rarely with effusions.

Answer 36.7. The answer is D.

The incidence of peritoneal mesothelioma is increasing and it currently

accounts for 25% to 33% of all mesotheliomas. This disease has a median

age at presentation of 60 years and is more common in men with a ratio

of 3 to 1. There is a clear relationship between peritoneal mesothelioma

and heavy exposure to airborne asbestos fibers, and approximately 50%

of patients have pleural plaques.