Desmoplastic cerebral astrocytoma of infancy. A case report with immunohistochemical, ultrastructural and proliferation studies

RELA fusion-positive ependymoma accompanied by extensive desmoplasia: a case report

We report a case of 33-year-old Japanese male who presented with a headache and visual disturbances. Magnetic resonance imaging revealed a large tumor in the left frontal lobe, measuring 7 cm in diameter, which was diagnosed as supratentorial anaplastic ependymoma accompanied by extensive desmoplasia. The patient underwent a gross total resection. Histologically, the tumor cells had oval or short, spindle-shaped nuclei, and proliferating cells in perivascular pseudorosettes with anucleate zones and mitotic figures. Desmoplasia with abundant collagen fibers among the tumor cells was detected at numerous sites, and perinuclear dot- or ring-like immunoreactivity for epithelial membrane antigen was identified. Five years and six months after the initial procedure, a small recurrent tumor was identified at the removal site. The patient underwent a second total resection. The histology of the resected tumor showed decreased collagen production and more apparent anaplastic features as compared to those of the initial tumor. In addition to the histological findings, molecular examinations revealed ependymoma, RELA fusion positive. Although not commonly observed, this case suggests that desmoplasia could be associated with ependymomas, including RELA fusion-positive variant. Moreover, our findings indicate that high-grade ependymoma requires careful, long-term follow-up even if gross total resection is performed.

Desmoplastic Infantile Ganglioglioma/Astrocytoma (DIG/DIA) Are Distinct Entities with Frequent BRAFV600 Mutations

Desmoplastic infantile ganglioglioma (DIG) and desmoplastic infantile astrocytoma (DIA) are extremely rare tumors that typically arise in infancy; however, these entities have not been well characterized in terms of genetic alterations or clinical outcomes. Here, through a multi-institutional collaboration, the largest cohort of DIG/DIA to date is examined using advanced laboratory and data processing techniques. Targeted DNA exome sequencing and DNA methylation profiling were performed on tumor specimens obtained from different patients (n = 8) diagnosed histologically as DIG/DIGA. Two of these cases clustered with other tumor entities, and were excluded from analysis. The remaining 16 cases were confirmed to be DIG/DIA by histology and by DNA methylation profiling. Somatic BRAF gene mutations were discovered in 7 instances (43.8%); 4 were BRAFV600E mutations, and 3 were BRAFV600D mutations. Three instances of malignant transformation were found, and sequencing of the recurrence demonstrated a new TP53 mutation in one case, new ATRX deletion in one case, and in the third case, the original tumor harbored an EML4-ALK fusion, also present at recurrence. DIG/DIA are distinct pathologic entities that frequently harbor BRAFV600 mutations. Complete surgical resection is the ideal treatment, and overall prognosis is excellent. While, the small sample size and incomplete surgical records limit a definitive conclusion about the risk of tumor recurrence, the risk appears quite low. In rare cases with wild-type BRAF, malignant progression can be observed, frequently with the acquisition of other genetic alterations.Implications: DIG/DIA are a distinct molecular entity, with a subset frequently harboring either BRAF V600E or BRAF V600D mutations. Mol Cancer Res; 16(10); 1491-8. ©2018 AACR.

Desmoplastic astrocytoma: new insights into its clinical profile, diagnosis, and treatment

BACKGROUND

Desmoplastic astrocytoma (DA) is a rare intracranial tumor which usually affects pediatric patients. The aim of this study is to describe the clinical features and management of DA based on a joint analysis of the cases reported in the scientific literature.

MATERIAL AND METHODS

A thorough review was carried out, gathering those pathologically proven DAs reported since the first description of this entity. Two new own cases were included in order to illustrate this review. Epidemiological, clinical, radiological, therapeutic, and follow-up data were analyzed with the software SPSS version 20.

RESULTS

A total of 52 DAs were recorded. Most cases occurred in the first 2 years of life, although older patients were also reported. Patients mainly presented symptoms and signs of elevated intracranial pressure. According to their radiological features, we were able to classify DAs in four main groups, with distinct differential diagnosis and prognosis. After treatment, 14.2 % of patients presented persistent neurological impairment and the mortality rate was close to 10 %.

CONCLUSION

DAs can be diagnosed at any age from birth to adolescence. These neoplasms can show up a wider range of radiological morphologies than previously thought. Surgery represents the treatment of choice for DAs, although chemotherapy can also be useful in the setting of recurrence or progression of the disease. Those DAs lacking classic radiological features, especially type 4 tumors, were linked with a poorer clinical outcome.

Desmoplastic infantile astrocytoma and characteristics of the accompanying cyst. Case report

A desmoplastic infantile astrocytoma (DIA) is an extremely rare tumor that comprises a solid astrocytic tumor accompanied by a large cyst and involves the superficial cerebral cortex and leptomeninges in infants. The solid part of this type of tumor has been well described in various reports and books, but characteristics of the cystic portion have remained unclear. Because adequate resection is required to ensure a favorable prognosis, information about the cyst is very important for diagnostic purposes and surgical planning. The authors report on the clinical and histological features of the cyst in a case of a DIA. A 12-month-old boy presented with vomiting. Contrast-enhanced magnetic resonance imaging revealed a strongly enhancing single-lobed large cyst located in the deep white matter, under the solid part of the tumor attached to the dura mater of the left frontal lobe. Both the solid and cystic portions of the tumor were surgically removed. The border between the cyst wall and surrounding white matter was unclear. Histologically, the cyst wall was composed of gliosis representing a rough accumulation of reactive astrocytes, lymphocytes, and small capillary vessels in edematous parenchyma, but no tumor cells. The present case and previous reports suggest that the cyst does not contain tumor cells, even if strongly depicted on contrast-enhanced neuroimaging, and that a thickly enhancing cyst wall indicates gliosis with accumulation of numerous small vessels.

MR findings of desmoplastic cerebral astrocytoma of infancy

Desmoplastic cerebral astrocytoma of infancy (DCAI) presents as a large supratentorial mass consisting of a central cystic component and an enhancing solid component associated with peripheral dural attachment. We report the unusual MR findings of a DCAI that differed from previously reported cases in terms of the presence of calcification, which is not considered a feature of this tumor, and the absence of an enhancing peripheral dural component.

I. Perinatal brain tumors: a review of 250 cases

Central nervous system tumors occur considerably less often in the fetus and neonate than in the older child. These tumors are not entirely the same as those found later in life. Their location, biologic behavior, response to therapy, and histologic types are different. Reports of 250 fetal and neonatal brain tumors were collected from the literature and studied for this review. The overall survival rate was 28%. The entire cranial cavity may be filled with tumor, and stillbirth is not uncommon. Macrocephaly was the most frequent presentation regardless of histology. Outcome is related to the size and location of the tumor, the histologic type, surgical resectability, and the condition of the infant at the time of diagnosis. Neonates with choroid plexus papillomas, gangliogliomas, and low-grade astrocytomas have the best prognosis, whereas those with teratomas and primitive neuroectodermal tumors have the worst prognosis.

Desmoplastic cerebral astrocytoma of infancy intermingling with atypical glial cells

Despite the rarity of desmoplastic cerebral astrocytoma of infancy (DCAI), it has distinct clinical and pathological features. The present case is a typical DCAI except for its detection and operational age and intermingling with pleomorphic glial cells. In this case, although a cystic lesion of the right temporal lobe was noticed when the patient was 6 months old, it was not regarded as a tumor and wasn't removed until he was 9 years old. It is quite unusual that a DCAI was able to exist in the cerebrum for 9 years. However, no metastasis occurred and distinct macroscopic and microscopic features of the tumor were not different from typical DCAI except for an intermingling with pleomorphic glial cells. Furthermore, even in the pleomorphic areas, the absence of necrosis and an MIB-1 index of 2.9% indicated non-aggressive growth. These features of the present case may provide additional information as to the character of DCAI, which generally has a favorable prognosis.

Unique desmoplastic cerebral tumor in a patient with complex partial seizures

Primary brain tumors with prominent desmoplasia include the gliofibroma, desmoplastic infantile ganglioglioma (DIG), pleomorphic xanthoastrocytoma (PXA), and desmoplastic cerebral astrocytoma. In the present report, we describe unusual pathological appearances in two successive resections of a left temporal tumor in a patient with complex partial seizures. Both tumors showed focal astroglial and very prominent neuronal differentiation. In the first resection at age 11 years, the tumor showed only focal desmoplastic areas and prominent neuronal differentiation with bizarre atypical giant cells. In the second resection at age 14 years, the morphology was dramatically different. Now the tumor showed marked desmoplasia with tumor cells coexpressing neuronal and glial markers. Electron microscopy showed prominent neuronal differentiation in both resections and presence of basal lamina around tumor cells. Our case represents a unique example of an extraordinary degree of neuronal differentiation in a desmoplastic cerebral tumor. While cellular pleomorphism in a desmoplastic tumor traditionally suggests the diagnosis of PXA, we wish to underscore that many cells exhibiting marked cytologic atypia may in fact be of neuronal rather than of glial origin as in our case.

Ultrastructural pathology of glial brain tumors revisited: a review

The ultrastructural pathology of primary brain tumors of glial origin is examined. These are divided into two major groups. The first category comprises astrocytoma with the variants: fibrillary, protoplasmic, gemistocytic, and anaplastic. These are biologically aggressive tumors of a relatively high proliferative potential and include a substantial proportion of cases that transform into the most malignant secondary glioblastoma. The second category, comprised of rather benign tumors of a limited proliferative capacity and a reasonable good prognosis, includes such clinico-pathological entities as pilocytic astrocytoma, pleomorphic xanthoastrocytoma, and subependymal giant cell astrocytoma of tuberous sclerosis. There is no ultrastructural feature, however, which makes it possible to discriminate between major subclasses of astrocytes; but secondary glioblastoma cells, while still retaining the stigmata of neoplastic astrocytes, are characterized by nuclei that seem to be more indented, cisterns of the endoplastic reticulum may be distended, and intranuclear pseudoinclusions are frequently observed. Primary glioblastoma, which probably originates de novo, is characterized by poorly differentiated cells with a paucity of subcellular organelles and no obvious features of astrocytic origin. Granular cell tumor also belongs to neoplasms of astrocytic lineage and the hallmark of this entity is a cell characterized by the presence of numerous membrane-bound, electron-dense autophagic vacuoles. Its malignant analogue is the granular cell glioblastoma. Two subtypes of granular cell glioblastoma have been distinguished. The first is characterized by the presence of numerous granular, electron-dense bodies which correspond to autophagic vacuoles. The second type is characterized by numerous electron-dense, amorphous masses within cellular processes. These electron-dense inclusions are virtually indistinguishable from minute Rosenthal fibers. The pilocytic astrocytoma is virtually indistinguishable at the ultrastructural level from fibrillary astrocytomas but cells tend to be more elongated. Besides Rosenthal fibers, two types of distinctive structures are relatively common in pilocytic astrocytomas: eosinophilic hyaline droplets and round granular bodies, which are composed of large aggregates of electron-dense secondary lysosomes or small electron-dense bodies, respectively. Pleomorphic xanthoastrocytoma is characterized by astrocytes surrounded by basal membranes. It belongs to a peculiar category of astrocytic "desmoplastic" brain tumors occurring in younger patients, the common denominator for which is the presence of basal lamina. The last category in this group is subependymal giant cell astrocytoma, a tumor of bivalent (glial and neuronal) differentiation, the cells of which are characterized by the presence of peculiar crystalloids. The hallmark of oligodendroglioma is the presence of concentric arrays of membranes (so-called membrane laminations, whorls, or scrolls). A fragment of the cytoplasm sequestrated within a particular whorl may contain mitochondria, lysosomes, or abundant glycogen granules. Ependymomas are characterized by a florid picture dominated by the presence of microlumina, cilia with basal bodies (blepharoplasts), microvilli, and long, interdigitating intercellular junctions of the zonulae adherentiae type. Ganglioglioma, the last category covered by this review, is a mixed glio-neuronal tumor. While glial cells are indistinguishable from their counterparts encountered elsewhere (mostly pilocytic astrocytes), the ganglion cells are characterized by abundant intracytoplasmic dense-core vesicles, absence of intermediate filaments, and numerous microtubules. Occasionally a close apposition of ganglion cells and Rosenthal fibers is seen. Dense-core vesicles are pleomorphic and ranged in a diameter from small synaptic vesicles to large lysosome-like neurosecretory granules.

Central nervous system neoplasms: indications for electron microscopy

Diagnostic dilemmas of biopsy specimens in the central nervous system (CNS) tumors are often the result of multiple factors, including fixation artifact, biopsy size, lack of immunohistochemical techniques to distinguish cell types, and unawareness of rare entities. Correct diagnosis and confirmation of diagnosis of primary CNS neoplasms is imperative and may require electron microscopic examination. In some instances, use of electron microscopy may be the only approach for accurate recognition of an entity. Although diagnostic electron microscopy is expensive and cost cutting is encouraged in today's practice of medicine, cost must be weighed against the consequences of even 1 patient developing CNS treatment-related necrosis or a radiation-induced neoplasm secondary to misdiagnosis of a benign entity. This study reviews the ultrastructural differences of three groups of diagnostically difficult CNS lesions: clear cell neoplasms (ependymoma, oligodendroglioma, central neurocytoma), rare entities containing astrocytes invested by a basal lamina (pleomorphic xanthoastrocytoma, the desmoplastic neuroepithelial tumors of infancy), and benign entities characterized by transitional cell forms (subependymoma, subependymal giant cell astrocytoma).

Pleomorphic xanthoastrocytoma with a gangliomatous component: an immunohistochemical and ultrastructural study

We report a case of a 24-year-old woman with left temporal pleomorphic xanthoastrocytoma (PXA) with atypical neuronal cells. Many neoplastic cells, otherwise typical of PXA, expressed glial fibrillary acidic protein, while neuronal cells with marked atypia were immunopositive for synaptophysin and neurofilament protein. This report supports a notion that PXA, like other astrocytic tumors, may have its gangliogliomatous counterpart.