Case 1

submitted by:
Daniel J. Brat
Emory University Hospital
Atlanta, Georgia

Clinical Summary:

Over a period of 6 months, a 31-year-old female developed headaches, nausea and vomiting and experienced short periods of unconsciousness. An MRI scan revealed a homogeneously contrast-enhancing tumor in the third ventricle, measuring 3 cm in greatest diameter, which appeared to arise in the hypothalamic/suprasellar region.

Case 1 - Figure 1 - Chordoid glioma of the third ventricle. T1-weighted magnetic resonance image following contrast injection demonstrating a sharply demarcated, solid and homogeneously enhancing mass in the third ventricle.

Case 1 - Figure 2 - Chordoid glioma of the third ventricle. Cords of epithelioid tumor cells are disposed in a basophilic, myxoid matrix.

Case 1 - Figure 3 - Chordoid glioma of the third ventricle. Note conspicuous lymphoplasmacellular infiltration of the lesion - a consistent histologic feature of chordoid gliomas.

Case 1 - Figure 4 - GFAP - Chordoid glioma of the third ventricle. As demonstrated in this immunohistochemical preparation, chordoid gliomas exhibit diffuse cytoplasmic labeling for glial fibrillary acidic protein.

Case 2

submitted by:
Peter C. Burger
Johns Hopkins Hospital
Baltimore, Maryland

Clinical Summary:

A 37-year-old-woman was evaluated two days after a seizure. A large, intra-axial, non-enhancing mass was found in the left frontal lobe.

Case 2 - Figure 1 - Astrocytoma. Note somewhat elongated, oval and mildly pleomorphic nuclei in this cytologic preparation. (A) A large, expansile, intra-axial left frontal lobe mass is present in a T2-weighted MR image.

Case 2 - Figure 2 - Astrocytoma. Characteristic of the fibrillary astrocytomas are a patternless infiltrate, nuclear pleomorphism with angulated and oval contours, and eosinophilic cytoplasmic processes. (B) The lesion does not enhance (T1-weighted, post contrast image).

Case 2 - Figure 3 - Astrocytoma. Many diffuse fibrillary astrocytomas exhibit nuclear immunolabeling for p53. Widespread labeling of this sort is encountered in only a small minority of oligodendrogliomas. (C) Photomicrograph.

Case 3

submitted by:
Thomas J. Cummings
Duke University Medical Center
Durham, North Carolina

Clinical Summary:

A 1-year-old Caucasian female presented with a seizure. Neurological examination showed no deficits. Magnetic resonance imaging (MRI) of the brain showed a large cystic lesion with contrast enhancement in the right temporal lobe. She underwent a right temporal craniotomy and gross total resection of the lesion, which intraoperatively appeared to have a distinct margin with the surrounding brain. She did not receive any postoperative chemotherapy or radiation therapy. Two years postoperative she is seizure-free, has no focal deficits, and has no evidence of tumor recurrence.

Case 3 - Figure 1 - Desmoplastic Infantile Ganglioglioma. T1-weighted coronal magnetic resonance image (MRI) shows a large cyst-enhancing lesion in the right temporal lobe typical of the DIG.

Case 3 - Figure 2 - Desmoplastic Infantile Ganglioglioma. Prominent desmoplasia and a spindled appearance is a characteristic feature of this neoplasm (H&E).

Case 3 - Figure 3 - Desmoplastic Infantile Ganglioglioma. A neoplastic neuronal component separates DIG from the desmoplastic infantile astrocytoma (H&E).

Case 3 - Figure 4 - Desmoplastic Infantile Ganglioglioma. Focal areas of small primitive neuroblastic appearing cells are typically seen (H&E).

Case 3 - Figure 5 - Trichrome - Desmoplastic Infantile Ganglioglioma. A Masson trichrome histochemical stain shows the prominent green-staining collagen content.

Case 3 - Figure 6 - Reticulin - Desmoplastic Infantile Ganglioglioma. A histochemical stain for reticulin shows a dense pericellular reticulin network.

Case 4

submitted by:
Gregory N. Fuller
Anderson Cancer Center
Houston, Texas

Clinical Summary:

In the late summer of 2002 a 71-year-old man with a history of myelodysplasia five months out from a matched unrelated donor stem cell transplant developed progressively increasing weakness and was noted to have a fever of 38.3°C. The patient had been receiving regular blood product transfusions for anemia and thrombocytopenia. He was admitted to an outside hospital for presumed infection and was started on multiple antibiotics. Following several family-witnessed seizure-like episodes the patient was started on phenytoin and transferred to MDACC. Upon admission, an EEG showed marked diffuse generalized slowing that was non-reactive to exogenous stimulation, consistent with severe encephalopathy. An MRI showed multiple bright signal intensities on T2-weighted and FLAIR sequences throughout the brain stem, including the medulla, pons and midbrain. Lumbar puncture showed normal glucose with elevated protein (147 mg per deciliter). A Gram stain for bacteria, India ink preparation for cryptococcus and bacterial cultures were negative. Serum samples were sent to the CDC for viral pathogen PCR testing. The patient developed progressive liver failure, attributed to graft-versus-host disease, and became increasingly obtunded. He died one week after admission and an autopsy was performed.

Case 4 - Figure 1 - West Nile Encephalitis. Although non-specific, the most distinctive morphologic feature of West Nile encephalitis is the microglial nodule. At the low scanning magnification shown here (40x), a microglial nodule is recognized as a localized area of hypercellularity in an otherwise evenly distributed neuropil, inviting closer inspection. (H&E)

Case 4 - Figure 2 - West Nile Encephalitis. At higher magnification (100x), microglial nodules consist of a heterogeneous mixture of cellular elements, including microglia, reactive astrocytes and lymphocytes. Microglial nodules can be seen in both the gray matter and the white matter in West Nile encephalitis. (H&E)

Case 4 - Figure 3 - West Nile Encephalitis. Some microglial nodules incorporate degenerating neurons and, occasionally, frank neuronophagia. (H&E, 100x)

Case 4 - Figure 4 - West Nile Encephalitis. Perivascular lymphocytic infiltrates are also commonly seen in West Nile encephalitis. (H&E, 100x)

Case 5

submitted by:
Anthony T. Yachnis
University of Florida Medical College
Gainesville, Florida

Clinical Summary:

The patient is a 1-year-old male who presented with failure to thrive and recent onset of vomiting. His weight was in the 10 percentile on admission despite an apparently normal caloric intake. Birth history was unremarkable. Imaging studies revealed a 3.3 x 2.4-cm contrast-enhancing mass in the region of the hypothalamus and optic chiasm. A bifrontal craniotomy was performed and extensive internal debulking of the mass was accomplished by a transventricular approach.

Case 5 - Figure 1 - Astrocytoma, pilomyxoid variant. Low magnification photomicrograph showing loose, monomorphous cytoarchitecture. 500X.

Case 5 - Figure 2 - Astrocytoma, pilomyxoid variant. Angiocentric pseudorosette-like arrangement of tumor cells and microcystic, focally myxoid background. 1000X.

Case 5 - Figure 3 - GFAP - Pilomyxoid astrocytoma immunostained for glial fibrillary acidic protein showing strong reactivity of piloid tumor cell processes, especially in perivascular regions. 1000X.