Unique desmoplastic cerebral tumor in a patient with complex partial seizures

The origin of Rosenthal fibers and their contributions to astrocyte pathology in Alexander disease

Rosenthal fibers (RFs) are cytoplasmic, proteinaceous aggregates. They are the pathognomonic feature of the astrocyte pathology in Alexander Disease (AxD), a neurodegenerative disorder caused by heterozygous mutations in the GFAP gene, encoding glial fibrillary acidic protein (GFAP). Although RFs have been known for many years their origin and significance remain elusive issues. We have used mouse models of AxD based on the overexpression of human GFAP (transgenic, TG) and a point mutation in mouse GFAP (knock-in, KI) to examine the formation of RFs and to find astrocyte changes that correlate with the appearance of RFs. We found RFs of various sizes and shapes. The smallest ones appear as granular depositions on intermediate filaments. These contain GFAP and the small heat shock protein, alphaB-crystallin. Their aggregation appears to give rise to large RFs. The appearance of new RFs and the growth of previously formed RFs occur over time. We determined that DAPI is a reliable marker of RFs and in parallel with Fluoro-Jade B (FJB) staining defined a high variability in the appearance of RFs, even in neighboring astrocytes. Although many astrocytes in AxD with increased levels of GFAP and with or without RFs change their phenotype, only some cells with large numbers of RFs show a profound reconstruction of cellular processes, with a loss of fine distal processes and the appearance of large, lobulated nuclei, likely due to arrested mitosis. We conclude that 1) RFs appear to originate as small, osmiophilic masses containing both GFAP and alphaB-crystallin deposited on bundles of intermediate filaments. 2) RFs continue to form within AxD astrocytes over time. 3) DAPI is a reliable marker for RFs and can be used with immunolabeling. 4) RFs appear to interfere with the successful completion of astrocyte mitosis and cell division.

Clinical heterogeneity of desmoplastic infantile ganglioglioma: a case series and literature review

Desmoplastic infantile gangliogliomas (DIG) are intracranial tumors described in 1987 as benign lesions of infancy. A literature review and the clinical course of 3 patients reported herein suggest that the initial description should be amended. Nearly 23% of DIG cases occur in children older than 24 months. Approximately 40% of DIG cases require additional medical, radiation, and/or further surgical intervention, and 15% of infants and children develop leptomeningeal spread or die from DIG. Such adverse outcomes, combined with the recognition that DIG represents a heterogeneous disease, underscore the need for an expanded biological and molecular investigation.

Desmoplastic infantile and non-infantile ganglioglioma. Review of the literature

Desmoplastic gangliogliomas (DIG) are rare primary neoplasms that comprise 0.5-1.0% of all intracranial tumors. Clinically, there are two forms of DIG, the infantile and the non-infantile. These tumors invariably arise in the supratentorial region and commonly involve more than one lobe, preferentially the temporal and frontal. On neuroimaging are seen as large hypodense cystic masses with a solid isodense or slightly hyperdense superficial portion. The histologic diagnosis is characterized by the presence of three different cell lines: astrocytic, neuronal, and primitive neuroectodermal marker sites, which were demonstrable. The treatment of choice is radical surgical excision, and if this is done, achieved complete healing of the patient does not require additional treatment. A literature review of DIG was compiled through Medline/Ovid using the keywords "desmoplastic infantile ganglioglioma", "desmoplastic non-infantile ganglioglioma" covering the years 1984-2009. We present a review of a total of 113 cases of infantile (94) and non-infantile gangliogliomas (19) published to date, examining the clinical, radiologic, surgical, and pathological aspects, as well as the outcome. Desmoplastic gangliogliomas represent a rare tumor group with two well-defined age groups, the children and non-children. Desmoplastic infantile gangliogliomas are the most common and occur in children below 5 years of age, and the large majority of them present within the first year of life. Surgery is the treatment of choice and no complementary treatment is needed in cases of complete tumor resection.

Desmoplastic noninfantile ganglioglioma: report of a case

Desmoplastic infantile ganglioglioma is a rare superficial supratentorial tumor that occurs within the first two years of life. Despite the worrisome radiological and histological appearance, the tumors are often curable following gross total resection. Tumors with similar characteristics are exceedingly rare in the noninfantile population. We present a six-year-old boy with seizures, weakness, and unsteady gait. Radiographic imaging confirmed a very large, solid and cystic mass in the right temporal-parietal region. Pathological examination demonstrated a tumor with severe desmoplasia identical to those reported as "desmoplastic infantile ganglioglioma." This case adds to the limited data available for desmoplastic gangliogliomas in the noninfantile population. It is not clear, yet likely, that the noninfantile form of this neoplasm is biologically similar to the infantile form. It is also unclear whether the desmoplastic noninfantile ganglioglioma has characteristics similar to classical ganglioglioma. This rare case highlights the remarkable versatility of glioneuronal tumors in children.

Good clinical course in infants with desmoplastic cerebral neuroepithelial tumor treated by surgery alone

We investigated why surgery alone provides for a benign clinical course in patients with desmoplastic infantile ganglioglioma and astrocytoma (DIG/A). The clinical course of 4, less than six-month-old girls, surgically treated at our institutions, was evaluated retrospectively. All presented with the clinical symptom of increasing head circumference. CT and MRI scans revealed a solid tumor attached to the dura that was surrounded by large, multiple cysts, in fronto-temporo-parietal lobe. Gross total removal succeeded in all 4 cases because the solid components of the tumor were very firm in contrast to the soft adjacent brain tissue. Microscopically, the surgical specimens consisted almost entirely of dense fibrous connective tissue containing generally elongate cells with inconspicuous cytoplasm. Most of these cells were immunopositive for GFAP. There was no evidence of tumor cells in the cyst wall. In 3 cases, some small neurons were positive for neurofilament immunostain. A high proportion of undifferentiated small cells in a less demoplastic area far from the dura were immunopositive for MIB-1. All of the 4 patients have been free of recurrence for more than five years. In patients with DIG/A, there are 5 reasons for a good clinical course. [1] At surgery, the tumor margin is clearly discernible because of the difference between the solid tumor and the soft adjacent brain tissue. [2] The tumor is located in the superficial cerebral hemisphere. [3] Large, multiple cysts surround the tumor. [4] The growth point appears to be adjacent to the cysts. [5] The cyst walls are free of invading tumor cells.