Joseph C. Parker

Choroid Plexus Carcinoma

Choroid plexus carcinoma is an uncommon neoplasm of the central nervous system most commonly found in the pediatric population. It is associated with a dismal prognosis, especially if incompletely resected. Accurate histopathologic diagnosis is imperative, and this neoplasm should always be included in the differential diagnosis of a papillary intraventricular tumor. Histopathologic features include blurring of papillary architecture, layers of neoplastic choroid plexus epithelial cells with pleomorphic nuclei, increased nuclear-to-cytoplasmic ratio, increased mitotic activity, areas of necrosis, and brain invasion. Current accepted treatment is gross total surgical resection of the tumor as the goal. Use of adjuvant chemotherapy is controversial at this time; however, it is considered in some cases.

Aicardi Syndrome: A Morphologic Description with Particular Reference to Intracytoplasmic Inclusions in Cortical Astrocytes

Aicardi syndrome is characterized by agenesis of the corpus callosum, infantile spasms, and ocular anomalies. Very few morphologic descriptions have been made of the central nervous system of children with this syndrome. We performed a postmortem examination of the brain of a 13-year-old girl with clinically well-documented Aicardi syndrome. Gross examination revealed a small brain (745 g) with the right cerebral and cerebellar hemispheres smaller than the left. There was agenesis of the corpus callosum, and ectopic gray matter was scattered throughout the cerebral hemispheres. Both choroid plexus and arachnoid cysts were present. Microscopic examination revealed indistinct cortical layering and multiple foci of ectopic gray matter. The cerebellar sections were altered by focal atrophy with gliosis and Purkinje cell dropout. Multiple sections of cerebrum contained astrocytes with coarse, paranuclear, eosinophilic inclusions. Electron microscopy, immunohistochemistry, and special stains further defined these inclusions, which we speculate represent a degenerative process.

Atypical Central Neurocytoma With Sarcomatous Differentiation

We report a case of an intraventricular tumor with features of atypical central neurocytoma with a sarcomatous component in a 44-year-old woman who presented with headaches and vomiting. Magnetic resonance imaging revealed a 3.4-cm lobulated enhancing mass in the occipital horn of the left lateral ventricle, and the patient subsequently underwent a left occipital-parietal craniotomy for debulking. The tumor contained 2 cell populations: round cells with perinuclear halos in a fibrillary background, and spindle cells with oval nuclei arranged in interlacing fascicles with focal necrosis. The round cells had diffuse synaptophysin immunopositivity, while the spindle cells were diffusely immunopositive for vimentin and had intercellular reticulin. The mitotic activity (8 mitotic figures per 10 high-power fields) and the high Ki-67 proliferation index (15.0%) were consistent with atypical central neurocytoma with a sarcomatous component. Although different histologic variants have been described, this is the first reported case, to our knowledge, of central neurocytoma with spindle cell sarcomatous features.

46-YEAR-OLD MAN WITH A SPINAL CORD MASS

Medulloblastoma accounts for only 1% of all adult CNS tumors. Likewise, recurrence of adult medulloblastoma greater than 20 years after initial diagnosis is extremely rare.We describe a case of adult medulloblastoma with late relapse of disease. The patient was 24 years old when first diagnosed and was treated with total tumor resection and craniospinal radiation. At the age of 45, an enhancing 1.3 cm intradural extramedullary spinal cord lesion at T5 was discovered on MRI. This was presumed to be recurrent medulloblastoma in the form of drop metastasis and the patient was treated with spinal radiation. Several months following treatment, at the age of 46, a follow-up MRI demonstrated an enhancing 1.4 cm intradural extramedullary spinal cord lesion at T7. The lesion was resected and histopathologic examination was most consistent with medulloblastoma, late drop metastasis. Although rare, adult medulloblastoma recurring 20 years after initial diagnosis should always be considered in the main differential diagnosis when working up CNS lesions at or outside the primary tumor site.