Desmoplastic infantile ganglioglioma. Morphological, immunohistochemical and genetic features

Radiohistogenomics of pediatric low-grade neuroepithelial tumors

PURPOSE

In addition to histology, genetic alteration is now required to classify many central nervous system (CNS) tumors according to the most recent World Health Organization CNS tumor classification scheme. Although that is still not the case for classifying pediatric low-grade neuroepithelial tumors (PLGNTs), genetic and molecular features are increasingly being used for making treatment decisions. This approach has become a standard clinical practice in many specialized pediatric cancer centers and will likely be more widely practiced in the near future. This paradigm shift in the management of PLGNTs necessitates better understanding of how genetic alterations influence histology and imaging characteristics of individual PLGNT phenotypes.

METHODS

The complex association of genetic alterations with histology, clinical, and imaging of each phenotype of the extremely heterogeneous PLGNT family has been addressed in a holistic approach in this up-to-date review article. A new imaging stratification scheme has been proposed based on tumor morphology, location, histology, and genetics. Imaging characteristics of each PLGNT entity are also depicted in light of histology and genetics.

CONCLUSION

This article reviews the association of specific genetic alteration with location, histology, imaging, and prognosis of a specific tumor of the PLGNT family and how that information can be used for better imaging of these tumors.

Infantile and Noninfantile Desmoplastic Astrocytoma and Ganglioglioma: Only Different Age of Onset?

OBJECTIVE

The purpose of this study was to investigate clinical, pathological, and prognostic discrepancies between infantile and noninfantile desmoplastic astrocytoma/ganglioglioma patients.

METHODS

From January 2012 to December 2019, we retrospectively reviewed patients aged <18 years who underwent craniotomies at Beijing Tiantan Hospital. Patients diagnosed with desmoplastic infantile astrocytoma and ganglioglioma (DIA/DIG) were included.

RESULTS

The group consisted of 9 infantile patients and 8 noninfantile patients. The mean age of onset was 30.11 months in infantile patients and 103.75 months in noninfantile patients. Comparing with infantile patients, noninfantile patients had a mild female predominance (P = 0.335). The most common presentation in noninfantile patients was seizure (n = 4, 50%), whereas abnormal head circumference (n = 3, 33.3%) was the most common presentation in the infantile group. All cases showed a ki-67 index <2%. Preoperative tumor volume in infantile patients (213.98 cm³) was larger than that in noninfantile patients (21.99 cm³) (P = 0.043). Gross total resection was achieved in 5 (55.6%) infantile patients and 6 (75%) noninfantile patients (P = 0.62). All patients are alive by last follow-up visit, and 1 infantile patient recurred 8 months postoperative.

CONCLUSIONS

Infantile and noninfantile patients with DIA/DIGs share similar clinical and histopathological features. Compared with infantile patients, noninfantile patients tend to have different symptom predominance. Lesions in noninfantile patients are prone to present with different cystic-solid patterns and smaller volume. Patients with DIA/DIGs have favorable prognosis regardless of extent of resection.

The great neurosurgical masquerader: 3 cases of desmoplastic infantile ganglioglioma

Desmoplastic infantile ganglioglioma (DIG) is a rare, distinctive, supratentorial neoplasm with a generally favorable prognosis. Clinical, radiographic, and pathologic features can sometimes mimic those of a malignant tumor and other serious intracranial disorders. The author describes his experience with 3 cases of DIG, each of which initially masqueraded as another neurological disease with a very different prognosis. Case 1 was an infant boy referred for evaluation of a hemorrhagic infarction at birth. Case 2 was an infant girl referred for evaluation of a holohemispheric malignant neoplasm. Case 3 was an infant girl referred for evaluation of an intracranial mass believed to be a subdural empyema or possible sarcoma. In each case the lesion was resected and found to be a WHO grade I DIG. Each child has had a benign postoperative course. DIG can be mistaken for other serious neurological conditions including malignant neoplasm, cerebral infarction, and infection. It is prudent to consider this rare, low-grade resectable tumor in the differential diagnosis of atypical intracranial masses of childhood, as the impact on prognosis can be profound. The author discusses management strategies for DIG, including a role for molecular sequencing.

Novel suprasellar location of desmoplastic infantile astrocytoma and ganglioglioma: a single institution's experience

OBJECTIVE

The aim of this study was to describe the clinical presentation, imaging appearance, and differential outcomes based on tumor location in 7 patients with desmoplastic infantile astrocytoma and desmoplastic infantile gangliogliomas (DIA/DIG).

METHODS

Data of 7 patients with histopathology-proven DIA/DIGs and preoperative imaging were retrospectively reviewed, and age, sex, clinical presentation, imaging characteristics, tumor location, surgical procedure, postoperative morbidity, and overall mortality were recorded.

RESULTS

Two subgroups of patients with DIA/DIGs were found to exist based on whether their tumor was located in the cerebral hemispheres or suprasellar region. Nearly all patients presented with rapidly enlarging head circumference regardless of tumor location. However, ocular abnormalities, including nystagmus and preference for downward gaze, were specific for patients with suprasellar disease. These patients experienced significant postoperative complications and had poor long-term outcomes. In contrast, patients with hemispheric tumors underwent more extensive resection than patients with suprasellar tumors, had uneventful postoperative courses, and had no documented long-term comorbidities.

CONCLUSIONS

Postoperative course and long-term outcome for patients with DIA/DIGs were correlated to the anatomical location and radiographic appearance of their tumor at presentation, despite having histologically and molecularly indistinguishable, WHO grade I tumors.

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.

Supratentorial tumors typical of the infantile age: desmoplastic infantile ganglioglioma (DIG) and astrocytoma (DIA). A review

OBJECT

Desmoplastic infantile gangliogliomas (DIGs) and desmoplastic infantile astrocytomas (DIAs) are tumors typical of the infantile age. A large size, with a mixed solid and cystic component, clinical presentation with progressing signs of increased intracranial pressure, a prominent benign desmoplastic structure at histological examination, and a favorable clinical course in the majority of cases are the prominent features of these tumors. The objective of the present paper was to review the pertinent literature on the topic together with our personal experience, with the aim of an updated review of the subject.

RESULTS AND CONCLUSIONS

Only 28 papers are present in the literature devoted to DIGs and DIAs, most of them reporting on single cases or small series, with a total of 107 patients aged from 5 days to 48 months with a slight male prevalence. Most of the reported cases refer to supratentorial and hemispheric locations, a few cases involving the hypothalamic region, the posterior fossa, and the spinal cord. The typical MRI appearance is of large mixed solid and cystic tumors with a spontaneous hyperintense T2 appearance of the solid part which also shows a strong contrast enhancement. Mixed ganglionic and astrocytic cells are identifiable in DIGs, whereas DIAs are typically featured by the exclusive presence of glial cells. In both cases, more primitive cells may be observed, which present a higher number of mitoses and these areas can mimic the features of malignant astrocytomas. Surgery represents the treatment of choice; however, radical removal has been reported as possible only in around 30 % of the cases: the low age of the patients together with their low weight and the large size of and the hyper-vascularized structure of the tumors represent the main factors limiting surgery. Pure observation is considered as first choice in children undergoing a partial/subtotal tumor resection, chemotherapic regimens being considered in cases of recurrences after a second look surgery. Long-term prognosis is favorable with mortality being related mostly to the rare midline (i.e., hypothalamic) locations, which beyond the functionally relevant site, tend to have an unusually more aggressive histological behavior.

Malignant transformation of a desmoplastic infantile ganglioglioma in an infant carrier of a nonsynonymous TP53 mutation

INTRODUCTION

Desmoplastic infantile ganglioglioma is a rare intracranial neoplasm classified as World Health Organization grade I tumor under neuronal and mixed neuronal-glial tumors (2007 World Health Organization brain tumor classification). It is usually a good prognosis, but 40% of patients require further medical, radiation, and/or surgical intervention, and 15% develop leptomeningeal spread or die from desmoplastic infantile ganglioglioma. Transformation to malignant glioblastoma occurs, but the genetic alterations associated with the transformation are generally unknown.

METHODS

We describe a desmoplastic infantile ganglioglioma in a 2-month-old boy, which showed aggressive behavior, requiring debulking at 2.5 months of age and chemotherapy at 10 months of age after tumor progression. At 8.5 years of age he developed malignant transformation to glioblastoma. Chromosome microarray analysis using oligo array and genomic sequencing was performed on the biopsy specimen from 2 months of age and on the subsequent transformed malignant glioblastoma.

RESULTS

After being clinically stable for 7.5-years, transformation to glioblastoma transformation occurred. He did well for 1 year but subsequently died from tumor progression. Chromosome microarray analysis using oligo array performed on the biopsy specimen obtained at 2 months of age did not reveal significant abnormalities; but there were significant genomic deletions and duplications associated with the glioblastoma. These included multiple genomic losses involving 4q and Y, gains of 5q, and amplification of 12q14. Genomic sequencing revealed a single nucleotide variant, p.R248Q in exon 7 of TP53, in the primary desmoplastic infantile ganglioglioma and the glioblastoma multiforme.

CONCLUSIONS

The nonsynonymous variant (p.R248Q in exon 7) of the TP53 gene is predicted to alter the structure of the L2/L3 motif of the DNA binding domain of p53 protein. It was detected in the primary desmoplastic infantile ganglioglioma and glioblastoma multiforme. This child illustrates the rare recurrence of desmoplastic infantile ganglioglioma with malignant transformation to glioblastoma caused by a nonsynonymous TP53 mutation, providing explanation for other rare benign tumor transformations. The TP53 gene is a known primary site of genetic alteration that predisposes to malignant tumors, and this case indicates that it might also be involved in the behavior and outcome of desmoplastic infantile ganglioglioma. Therefore more genetic testing is recommended on desmoplastic infantile ganglioglioma tumors, which may provide biologic prognostic markers.

Genome-wide DNA copy number analysis of desmoplastic infantile astrocytomas and desmoplastic infantile gangliogliomas

Little is known about the molecular features of desmoplastic infantile ganglioglioma (DIG) and desmoplastic infantile astrocytoma (DIA). We performed a genome-wide DNA copy number analysis in combination with a multiplex ligation-dependent probe amplification-based analysis of copy number changes of candidate genes in 4 DIAs and 10 DIGs. Molecular inversion probe (MIP) assay showed that large chromosomal alterations were rare among DIG and DIA. Focal recurrent genomic losses were observed in chromosome regions such as 5q13.3, 21q22.11, and 10q21.3 in both DIA and DIG. Principal component analysis did not show any significant differences between the molecular profiles of DIG and DIA, and a hierarchical cluster analysis did not clearly separate the 2 tumor groups according to their molecular profiles. In 6 cases, gain of genomic material at 7q31 (corresponding to MET gene) was found in multiplex ligation-dependent probe amplification (MLPA) analysis. Furthermore, two cases showed gain at 4q12, and a single case showed BRAF mutation. In agreement with previous analyses, this study demonstrates the absence of consistent recurrent chromosomal alterations in DIA and DIG and overall rarity of the BRAF mutation in these tumors. Notably, these results suggest that DIA and DIG represent a histologic spectrum of the same tumor rather than 2 separate entities.

Strong desmin expression in a congenital desmoplastic infantile ganglioglioma mimicking pleomorphic rhadomyosarcoma: a case report including ultrastructural and cytogenetic evaluation and review of the literature

PURPOSE

Desmoplastic infantile gangliogliomas (DIGs) are rare tumors of infancy. Herein, we describe an unusual case of DIG diagnosed by prenatal ultrasound.

METHODS

This 5-day-old newborn was delivered after a prenatal ultrasound revealed a large cystic mass in the left cerebral hemisphere along with an echogenic solid component.

RESULTS

The tumor revealed a glial and neuronal proliferation in a background of desmoplasia more typical of DIG and a minor component with a more primitive, immature appearance to the glioneuronal elements. A significant component of the tumor was composed of pleomorphic eosinophilic spindle cells in whorls and interlacing fascicles that showed a strong, sharp, and diffuse positivity for desmin, thus mimicking rhabdomyosarcoma. However, the tumor cells were GFAP (+), INI-1 (+), and myogenin (-). Mitoses were seen both in the more spindle cell astroglial areas as well as the more primitive neuroepithelial cells. The MIB-1 proliferation index was brisk, exceeding 15 %, and in areas it was estimated to be as high as 30 %. Such high proliferation index has been described and accepted in the more primitive neuroepithelial areas, but not in the terminally differentiated, spindle cell astroglial areas as in our case. Our patient was incidentally diagnosed prenatally. To our knowledge, this case is the first documented congenital DIG diagnosed prenatally.

CONCLUSIONS

This case highlights the pitfalls in diagnosing DIG, which can mimic a rhabdomyosarcoma. Furthermore, it underscores the importance of re-evaluating the grading of these tumors or at least segregating the variants where the prognosis may be more guarded.

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 ganglioglioma of the spinal cord in a western European hedgehog (Erinaceus europaeus)

Gangliogliomas are composed of neoplastic glial and neuronal cells and are extremely rare tumors of the central nervous system of domestic animals. The present report describes the clinical presentation and the pathomorphological and immunophenotypical characteristics of a desmoplastic ganglioglioma in the spinal cord of a 3-year-old male western European hedgehog (Erinaceus europaeus). Clinically, the hedgehog exhibited a skin wound and therapy-resistant paresis of the left hind limb. Necropsy showed dilatation of the urinary bladder. Histologic examination of the thoracic spinal cord revealed a focally extensive infiltrative mass, which consisted of multiple nodules of smaller bipolar or oligopolar glial cells and variably sized polygonal, ganglionic, neuron-like cells embedded in variable amounts of microcystic neuropilic matrix. An area of spindle-shaped cells arranged in interwoven fascicles and surrounded by a prominent network of reticulin fibers was interpreted as desmoplastic leptomeningeal stroma. Immunohistochemistry revealed a moderate number of glial fibrillary acidic protein and S-100-positive cells and processes. In addition, the ganglionic neuron-like cells expressed neurofilament, microtubule-associated protein-2, and neuron-specific enolase. In summary, this spinal cord tumor was composed of astroglial and neuronal cellular elements, justifying the diagnosis of a desmoplastic ganglioglioma.

Desmoplastic non-infantile ganglioglioma in late adulthood

Desmoplastic infantile ganglioglioma (DIG) is an uncommon supratentorial neuroepithelial brain tumor that typically occurs in infants younger than 24 months. Desmoplastic non-infantile ganglioglioma (DNIG) is a rare variant of this intracranial neoplasm. There are only 16 DNIG cases reported in the literature, with all patients under the age of 25 at the time of presentation. These DIG and DNIG cases were radiologically and histologically similar, with good outcome after treatment. Despite the size and high mitotic index for patients with DNIG, the prognosis is generally favorable and gross total resection is sufficient. We present a case of a 59-year-old woman with a DNIG. To the best of our knowledge, this is the first case reported of DNIG in late adulthood. Clinical presentation, histological and radiological findings are discussed.

Genetic alterations in a papillary glioneuronal tumor

Papillary glioneuronal tumors (PGNTs) are rare lesions of the central nervous system, and no information exists on the genetic alterations in these neoplasms. The authors report on such a case in a child. Genetic studies revealed that the tumor was characterized by gains and structural alterations involving only chromosome 7 with breakpoints at 7p22. By using comparative genomic hybridization, the authors observed a high-level amplification region at 7p14~q12. Fluorescence in situ hybridization with a probe for EGFR revealed that this gene was not amplified. Similar to other patients with PGNTs, the patient in the present case fared well. From a genetic point of view the data in the present case are in accordance with previous findings of EGFR amplifications as uncommon in low-grade gliomas and gangliogliomas. Recurrent rearrangements of chromosome 7 have been noted in other mixed glioneuronal tumors. The data in this case suggest that genes located at chromosome 7 can also be involved in the pathogenesis of PGNT. In clinical terms it will be especially important to corroborate, through the analysis of further cases, the involvement of the chromosome 7p22 locus, a region where glial and neuronal linked genes (RAC1 and NXPH1) are known to be located.