1.D. Nelson p.51.Microaerophilic and anaerobic streptococci are the most frequently identified organisms in brain abscesses

2.A. For questions 2–9 see CNBR p.283.

3.C.

4.D.

5.B.

5.C.

7.D.

8.B.

9.B.

10.D. For questions 10–14 see Nelson pp.240–242.Neurofibrillary tangles and neuritic

11.D. plaques are both intracytoplasmic; both contain paired helical filaments and

12.C. are revealed with silver stains.The central core of the plaque is composed of

13.A. P/A4, not a protein.The tangles are immunoreactive for x protein.

14.C.

15.E. Nelson p.338.Vimentin and epithelial membrane antigen are expressed by the majority of meningiomas.

16.D. Nelson pp.316–317.Gangliogliomas are usually well circumscribed and can be partially cystic.

17.B. Friede pp.310, 390–391.Hypotelorism, not hypertelorism, is associated with trisomy 13.

19.A. For questions 19–28 see CNBR p.283.Diets heavy in corn lack tryptophan that

20.A. is used to synthesize niacin.Diets heavy in refined rice are more likely to lack

21.B. sufficient thiamine.Vitamin A toxicity may cause cerebral edema with a

22.A. pseudotumor presentation.Pernicious anemia can lead to a B12 deficiency with

23.A. megaloblastic anemia and subacute combined degeneration of the spinal cord.

24.B.

25.E.

26.C.

27.C.

28.D.

29.A. Nelson pp.352–354.Meningeal infiltration is the most common lesion in secondary lymphomas, and parenchymal lesions are the most common lesion in primary lymphomas.Most are of B-cell lineage and are radiosensitive.Nodular lymphomas are not seen in the central nervous system (CNS); all show a diffuse histology.

30.A. V&A p.1078.Cortical arteriovenous malformations (AVMs) are not characteristic of the Sturge-Weber syndrome.

31.B. Nelson p.196.The demyelination, spongiosis, and gliosis seen in vitamin B12 deficiency are most common at lower cervical and thoracic levels.

32.B. Nelson pp.87–88.Progressive multifocal leukoencephalopathy is caused by a papovavirus (notably the JC virus).Lesions occur mainly in the white matter and consist of foci of myelin and oligodendroglial cell loss with minimal inflammatory infiltrate.Hyperchromatic enlarged oligodendroglial nuclei are found at the margin of the lesions.

33.E. Mer p.375.Other associations are retinal hemangioblastomas, adrenal tumors, and polycythemia.The latter results from the production of a hematopoietic factor by the tumor.

34.B. For questions 34–38 see Nelson pp.428, 431–433.Schwannomas are charac-

35.B. terized by a biphasic cellular pattern composed of compact spindle cells

36.B. (Antoni A areas) and loosely arranged stellate cells (Antoni B areas).Also seen

37.A. are Verocay bodies, which result from the palisading of elongated nuclei

38.A. alternating with anuclear fibrillar material.Neurofibromas incorporate the parent nerve and hence have axons in their midst.The plexiform type is considered pathognomonic for neurofibromatosis type 1.

39.B. Nelson p.352.Hemorrhage is also common in melanoma, renal cell carcinoma, and lung carcinoma.

41.E.

42.D.

43.B.

44.A.

45.D. V&A pp.1185–1186.Acquired hepatocerebral degeneration is associated with gliosis with a predilection for the cortex.It tends to spare the hippocampus, globus pallidus, and deep folia of the cerebellar cortex.Widespread hyper-plasia of protoplasmic astrocytes is visible in the deep layers of the cerebral and cerebellar cortex and in deep nuclear structures.

46.E. V&A pp.1193–1195.Vitamin A excess has not been associated with central pontine myelinolysis.

47.A. Nelson pp.16, 261, 311.Rosenthal fibers, eosinophilic masses observed in astrocytic processes, are associated with pilocytic astrocytomas (neoplastic), and astrocytosis and Alexander’s disease (nonneoplastic).

48.D. Nelson pp.450–451.Neurofibromas and café au lait spots occur less commonly in neurofibromatosis type 2 (NF-2) than in NF-1.Bilateral acoustic neuromas are the hallmark of NF-2.Lisch nodules are rare in NF-2.

49.A. CNBR p.285

50.A. Nelson p.234.The motor nuclei of cranial nerves V, VII, IX, and XII as well as the motor cortex may be affected.

51.C. Nelson pp.131–34.Cavernous hemangiomas are composed of large, thin-walled vessels without interposed brain parenchyma.

52.E. For questions 52–57 see Nelson p.504.

53.A.

54.D.

55.C.

56.B.

57.A.

58.B. Burg p.17.Glomus jugulare tumors originate from foci of paraganglionic tissue around the jugular bulb.These invasive tumors contain neurosecretory granules similar to those in the carotid body.Some of them produce clinically detectable amounts of catecholamine.

59.D. Nelson pp.14, 82.The viral inclusions of herpes simplex type 1 (Cowdry type A) are dense, intranuclear, eosinophilic bodies found in neurons, astrocytes, and oligo-dendrocytes.They are more likely to be found early in the course of the disease.

60.A. Nelson p.362.High levels of human chorionic gonadotrophin are associated with choriocarcinomas, and high levels of alpha-fetoprotein are associated with endodermal sinus tumors (yolk sac tumors).

62.C. For questions 62–65 see Nelson pp.351–352.

63.B.

64.D.

65.E.

66.A. For questions 66–69 see CNBR pp.286, 376.

67.C.

68.A.

69.B.

70.C. Nelson 1 p.298.Subependymal giant-cell astrocytomas are characteristic of tuberous sclerosis.

71.A. Nelson p.362.

72.B. Nelson p.409.

73.C. For questions 73–83 see Nelson pp.197–202, 261–262.

74.D.

75.B.

76.E.

77.A.

78.A.

79.D.

80.C.

81.A.

82.A.

83.E.

84.B. For questions 84–88 see Nelson pp.205–206.

85.C.

86.D.

87.A.

88.E.

89.D. For questions 89–95 see Nelson pp.207–210.

90.A.

91.B.

92.E.

93.A.

94.D.

95.A.

97.C. For questions 97–100 see V&A pp.1128–1137.Both idiopathic Parkinson’s

98.B. disease and the Shy-Drager syndrome (a form of striatonigral degeneration)

99.A. are characterized by loss of cells in the zona compacta of the substantia

100.B. nigra, but in the latter disease is also found significant cell loss in the putamen and the intermediolateral column.Lewy bodies are not found in the Shy-Drager syndrome.Patients with this syndrome suffer from parkinsonian symptoms and orthostatic hypotension.

101.A. V&A p.802; Nelson p.96.Dementia, characterized by cognitive dysfunction, behavioral disturbance, and motor impairment, occurs in one-third to two-thirds of patients with AIDS.Myelopathy occurs in less than 10%, inflammatory polymyositis in 20%, toxoplasmosis in 10%, and lymphoma in 5% of AIDS patients.

102.B. V&A pp.1069–1072.The triad of adenoma sebaceum (actually angiofibromas), epilepsy, and mental retardation characterizes tuberous sclerosis.Although benign tumors (angiomyolipomas) of the kidney and other organs are seen, renal cell carcinomas are not.The other lesions listed are associated.

103.C. V&A pp.1074–1076.Hamartomas (not neurofibromas) of the iris (Lisch nodules) are seen in NF-1.

104.C. Nelson pp.130, 517.Cerebral amyloid angiopathy is confined to intracranial arteries and arterioles in the leptomeninges and superficial cortex.

105.B. V&A pp.1382–1383.The CSF in Guillain-Barré syndrome is under normal pressure, is acellular in 90% of patients, and demonstrates an increased protein level that peaks at 4 to 6 weeks after onset.Responses D and E are characteristic findings.

106.C. CNBR Fig.3-139, p.253.This is lymphoma with diffuse perivascular lymphocytic infiltration into the Virchow-Robin space around a blood vessel.Such lymphomas are often multiple, respond initially to steroids (but invariably recur), and are associated with immunosuppression in younger men.They also occur in immunocompetent males over 60 years.

107.B.

108.B. CNBR Fig.3-37.The inclusion bodies of HSV (dense, eosinophilic, and surrounded by a clear halo) and SSPE are intranuclear.The inclusion bodies seen in the other responses are intracytoplasmic.Smaller eosinophilic intracytoplasmic inclusions may also be seen in SSPE.

109.D. Pick’s bodies (rounded intracytoplasmic masses) are visible in the pyramidal neurons of the hippocampus.

111.B CNBR Fig.3-1.Alzheimer’s type II astrocytes (large vesicular nuclei and little visible cytoplasm) are present.These are found in hepatic encephalopathy and Wilson’s disease.

112.B. Nelson 1, Fig.7-26, p.139.The cells of this variant of astrocytoma have prominent eosinophilic cytoplasm, short processes, and eccentric nuclei.

113.D. Nelson Fig.5-1, p.83.The hemorrhagic appearance of the medial temporal lobe is characteristic of HSV-1.

114.E. CNBR Fig.3-43.Demyelination and oligodendroglial cell loss are seen.Residual oligodendroglial nuclei are large and bizarre.

115.D. CNBR Fig.3-44.Numerous vacuoles give a spongiform appearance.

116.B. CNBR Fig.3-173.The iris hamartomas (Lisch nodules) of NF-1 are seen.

117.A. CNBR Fig.3-45.Perivascular foci of inflammation with prominent multinu-cleated giant cells are typical.

118.C. CNBR Fig.3-79.The finding of abnormal ganglion cells (including binucleate forms) is key to the diagnosis of ganglioglioma.

119.D. CNBR Fig.3-68.A “chicken wire” vascular pattern and a monotonous nuclear array are seen.

120.C. CNBR Fig.3-85.Dense, hyperchromatic cells are radially arranged in Homer-Wright rosettes with central granulofibrillar material.

121.E. CNBR Fig.3-71.Mucinous material accumulating about a hyalinalized vessel wall is characteristic.

122.B. CNBR Fig.3-102.Palisading epithelial cells with keratinization and calcification are prominent.

123.C. CNBR Fig.3-100.Vacuolated “stromal” cells in a complex capillary network are seen.

124.D. Ok Fig.7-64A, p.257.Lipoma of the corpus callosum.

125.A. Nelson fig.10-3, p.178.Selective necrosis of the globus pallidus is noted.

126.B. CNBR Fig.3-59.Necrosis with pseudopalisading is well illustrated in this GBM.

127.D. CNBR fig.3-177.The adenoma sebaceum of tuberous sclerosis is seen.

128.C. CNBR Fig.3-93.Meningotheliomatous (syncytial) type of meningioma.

129.C. CNBR Fig.3-94.Fibrous type of meningioma.

130.D. CNBR Fig.3-149.Bundles of elongated Schwann’s cells with characteristic wavy nuclei in a loose mucinous or collagenous matrix are features of the neurofibroma.

131.B. CNBR Fig.3-152.Malignant peripheral nerve sheath tumors are composed of spindle cells in fascicles with occasional mitoses and foci of necrosis.

132.E. CNBR Fig.3-145.Verocay bodies, palisading elongated nuclei encircling anuclear fibrillary material, are hallmarks of schwannomas.

133.C. CNBR Fig.3-130.Chordomas feature “physaliferous” or “bubbly” cells surrounding pools of mucin.

135.C. CNBR Fig.3-189.Neuritic (“senile”) plaques (composed of degenerating nerve cell processes surrounding a central core of amyloid composed of â/A4 protein) and neurofibrillary tangles are seen.

136.C. Nelson Fig.13-41, p.262.Numerous Rosenthal fibers (eosinophilic material in cell processes) in areas of astrocytosis are noted.

137.D. Nelson Fig.8-10a, p.127.A massive basal ganglia hypertensive hemorrhage is noted.

138.A. CNBR Fig.3-91.A dense array of uniform undifferentiated cells with small blue nuclei and perinuclear halos is found in neurocytomas.The findings are similar to oligodendrogliomas, but central neurocytomas stain with synap-tophysin and neuron-specific enolase (NSE).

139.B. CNBR Fig.3-279.Posterior columns, spinocerebellar tracts, and corticospinal tracts are affected.

140.E. Ok Fig.6-12A, p.195.There is a spongiform and gliotic appearance of the cord primarily affecting the posterior and lateral columns.

141.D. Ok Fig.6-16B, p.198.There is an irregular area of coagulation necrosis involving both gray and white matter.

142.C. CNBR Fig.3-282.Well-defined plaques are seen.

143.A. CNBR Fig.3-276.The anterior horn and corticospinal tract are affected.

144.E. Nelson Fig.20-10, p.453.Cortical tubers are seen in the frontal and temporal lobes.

145.B. CNBR Fig.3-70.The histologic appearance of ependymomas is highly variable.A cellular variety with sheetlike growth of oval to polygonal cells arranged in a pseudovascular rosette is illustrated.

146.E. Nelson Fig.16-161, p.365.Cartilage, mucin-producing epithelium, and immature spindle cell stroma are all part of this immature teratoma.

147.C. Ok fig.7-72A, p.264.Atrophy of the hemisphere and leptomeningeal venous angioma are present in this specimen with Sturge-Weber syndrome.

148.A. CNBR Fig.3-143.Dense Antoni A areas (with compact spindle cells) and looser Antoni B areas (with stellate cells) are typical of an acoustic neuroma (schwannoma).

149.D. CNBR Fig.3-137.Epitheloid cells with melanin inclusions are seen.

150.B. CNBR Fig.3-57.Cellular pleomorphism, hypercellulaity, and mitotic activity characterize this anaplastic astrocytoma.

151.D. The periventricular plaques of multiple sclerosis are seen.

152.C. CNBR Fig.3-188.Large confluent areas of dysmyelination with U-fiber sparing is typical of metachromatic leukodystrophy.

153.A. Ok Fig.7-62A, p.255.A large cerebellopontine angle epidermoid with white flaky, keratinous debris is illustrated.

154.B. CNBR Fig.3-139.A perivascular infiltration of cells with pleomorphicnuclear features characterizes this lymphoma.

156.C. Nelson Fig.9.18A, p.149.Extensive bilateral contrecoup contusions of the orbital surfaces and frontal poles are illustrated.

157.A. CNBR Fig.3-204A.The arterioles of the leptomeninges and superficial cortex are dilated, and amorphous material infiltrates the wall.

158.E. Nelson Fig.11.7, p.228.Selective atrophy of the frontal and temporal lobes consistent with Pick’s disease is noted.

159.C. Ok Fig.7-48A, p.245.The vascular mural nodule in the left cerebellar hemisphere and the associated cyst (midline) is consistent with a cerebellar hemangioblastoma.

160.D. CNBR Fig.3-112.The normal acinar, heterogenous appearance of the pituitary is replaced by a diffuse sheet of polygonal cells.

161.D. CNBR Fig.3-308.A section from normal sural nerve is illustrated.