Table 16.3 Primary Brain Tumors in Children
Supratentorial tum ors
Cerebral neuroblastoma (PNET)
Tum ors o f the pineal region
Endodermal sinus tumor
Cerebellar tum ors
Brainstem tum ors
Intraventricular tum ors
Choroid plexus papilloma
Choroid plexus carcinoma
PNET = primitive neuroectodermal tumor.
markers, and many tumors contain neurofilament protein,
negating their value in distinguishing these tumors from one
another. The absence of GFAP, however, is useful in differen-
tiating these tumors from malignant gliomas, and the lack of
lymphoid antigens and markers of epithelial and mesenchymal
cells helps distinguish these tumors from lymphoma, carci-
noma, and sarcoma.
Diagnostic Accuracy of Needle Aspiration
Comparison of diagnoses of intracranial masses sampled by
needle aspiration with histologically processed biopsy speci-
mens has shown a diagnostic accuracy of 87.5-90% .3,4 In one
series of 56 tumors, the precise histologic diagnosis was made
cytologically in 43 cases (77%).4 A major problem was pro-
duced by non-representative sampling. Thus, a common pitfall
in needle aspiration of cerebral masses is the misinterpretation
of reactive astrocytes as representing low-grade glioma. Reac-
tive gliosis is commonly present around abscesses, infarcts,
and metastases. If the needle fails to sample the lesion itself
and instead touches the periphery, reactive gliosis may be
Another pitfall is misclassification of primary CNS tumors.
In the absence of necrosis, one cannot confidently distinguish
glioblastomas from anaplastic astrocytomas, and oligodendrog-
liomas can be confused with anaplastic astrocytomas. Although
the distinction between metastases and high-grade gliomas may
occasionally be difficult on routine cytologic preparations, anti-
body panels are helpful in this situation.
and retinoblastomas, being composed of small cells with round,
hyperchromatic nuclei, inconspicuous nucleoli, and scant cyto-
plasm occurring in diffuse sheets.4 Rosettes can be seen in any
of these tumors but are less commonly seen in medulloblasto-
mas than in the other tumor types. As discussed previously, this
group of neoplasms typically expresses panneuroectodermal
CSF examination will continue to be a direct and effective
means to diagnose those conditions that primarily involve the
subarachnoid space, as well as those disorders located within
the parenchyma of the central nervous system. CSF cytology is
not without diagnostic problems and pitfalls. Thus, knowledge
of the clinical findings of the patient, tumor location, and dif-
ferential diagnosis of lesions within a location is required for
complete cytologic evaluation of the CSF sample.
Kish JK, Vallera DU, Ruby SG, et al.
Comparative study of non-gynecologic
processing by thinprep vs. conventional
methodology: Rationale for the use of
Bigner SH, Johnston WW.
of the Central Nervous System.
Masson 1981;75-124, 39-44, 59-62, 65-70.
Mouriquand C, Benabid AL, Breyton M.
Stereotaxic cytology of brain tumors.
Review of an eight-year experience.
Nguyen GK, Johnston ES, Mielke
BW. Cytology of neurorectodermal
tumors of the brain in crush prepara-
Trojanowski JQ, Atkinson B, Lee VM. An
immunocytochemical study of normal
and abnormal human cerebrospinal
fluid with monoclonal antibodies to
glial fibrillary acidic protein.
Wilkins RH, Odom GL. Ependymal-
choroidal cells in cerebrospinal fluid:
Increased incidence in hydrocephalic
Borowitz MJ, Bigner SH, Johnston
WW. Diagnostic problems in the
cytologic evaluation of
cerebrospinal fluid for lymphoma
Bigner SH, Johnston WW. The cytopa-
thology of cerebrospinal fluid. I. Non-
neoplastic conditions. Lymphoma and
Granter SR, Doolittle MH, Renshaw AA.
Predominance of neutrophils in the
cerebrospinal fluid of AIDS patients with
Am J Clin
10. Gupta PK, Gupta Pc, Roy S, et al. Herpes
simplex encephalitis cerebrospinal fluid
cytology studies — two case reports.
11. Katz RL, Alappattu C, Glass PJ, et al.
Cerebrospinal fluid manifestations of
the neurologic complications of human
immunodeficiency virus infection.
12. Grover D, Newsholme W, Brink N, et al.
Herpes simples virus infection of the cen-
tral nervous system in human immuno-
deficiency virus-type 1-infected patients.
Int J STD AIDS