Granular cell astrocytoma

Granular cell tumor of the brain: case report and review of literature

Granular cell tumors are rare tumors that develop from Schwann cells, which are glial cells surrounding neurons of the peripheral nervous system, which serve in the process of myelination. Granular cell tumors are rarely associated with the central nervous system in humans. In this report, we analyze a patient with granular cell tumor and review the current literature.

Ependymoma with C11orf95-MAML2 fusion: presenting with granular cell and ganglion cell features

C11orf95-RELA fusion or, less frequently, YAP1 fusion is recurrently detected in most cases of supratentorial ependymoma. Other fusions have rarely been reported in some cases of supratentorial ependymoma, and little is known about their pathological or clinical features. Here, we present a case of supratentorial ependymoma with unusual pathological findings and C11orf95-MAML2 fusion. A 23-year-old man was admitted to our hospital because of headache and vomiting. Magnetic resonance imaging revealed a cystic lesion in the right frontal lobe, and gross total resection of the tumor was performed. Pathologically, the tumor was mainly composed of typical ependymal lesions with perivascular pseudorosettes and contained some atypical lesions, with granular and ganglion cell features. The tumor was diagnosed as anaplastic ependymoma, which was classified as grade III on the World Health Organization scale, and found to be RELA fusion-positive in the DNA methylation analysis. However, the tumor was negative for C11orf95-RELA fusion, and RNA sequencing detected C11orf95-MAML2 fusion. The patient has not received adjuvant therapy and has remained alive without any evidence of disease for 30 months, suggesting that the prognosis might be better than that of typical C11orf95-RELA fusion-positive ependymoma.

Granular cell tumor a study of 42 cases and systemic review of the literature

BACKGROUND

Granular cell tumor (GCT) remains a diagnostic clinicopathologic problem because the exact frequency of its detailed morphological and clinical characteristics is unknown as most observations are collected from small series or isolated cases. Herein, our aim is to highlight the frequency of all clinicopathological characteristics of this rare tumor based in our series and the available medical (PubMed) literature.

MATERIAL AND METHODS

42 cases were evaluated for: tissue layers involved by the tumor (in skin and mucosae), growth pattern, nuclear pleomorphism, mitotic index, necrosis, spindling, calcification, hyalinization, and pustule-ovoid bodies of Milian, as well as perineural and vascular invasion, and the presence of adjacent epithelium changes, and lymphocytes and eosinophils infiltration., Follow-up was analyzed. The tumors were subclassified into benign, atypical and malignant according to Fanburg-Smith criteria and into benign or GCT of uncertain malignant potential according to Nasser criteria. The same characteristics were analyzed for 1499 cases reviewed according to PRISMA guidelines.

RESULTS

In the current series, the mean age at diagnosis was 45.8 years (range 6-69 years). Most patients were females (60 %) and the involved organs were by descending frequency: skin and subcutaneous tissue, bronchus, esophagus, breast, tongue, larynx, pharynx, gingiva, trachea, right colon, vulva, and hypopharynx. No recurrence or progression was seen, despite 32 cases were incompletely excised, with the exception of one malignant tumor. The growth pattern was either infiltrative (85.71 %) or well limited (7.14 %). Sixteen tumors had vesicular nuclei. Mitotic activity was found in two tumors. Lymphocytic infiltration was found in 14 tumors. Eosinophils were present in 6 cases. One GCT of the right colon showed extensive calcification and hyalinization. Perineural invasion was noted in 6 lesions. No vascular invasion was found. One tumor was clinically malignant and the patient died 2 years after diagnosis. Medical literature review showed similar results in terms of frequency of the reported clinical and morphological features. Among cases with available follow up, almost 20 % showed positive margins and of those 20 % developed local recurrence. According to the Fanburg-Smith criteria, 72 % would be benign, 17 % atypical and 11 % malignant tumors, while according to those of Nasser, 93 % would be benign and 7% of uncertain malignant potential. However, true malignancy, as affirmed by metastasis of GCT is found in almost 2.5 % of the cases.

CONCLUSION

GCT is a usually benign tumor, affecting any anatomic location. Necrosis and mitotic activity seem to be the most effective histologic criteria for detecting aggressive tumors, but the presence of metastasis (2.5 % of the cases) remains the most accepted definitive criterion for diagnosis of malignant GCT.

Intraoperative assessment of isocitrate dehydrogenase mutation status in human gliomas using desorption electrospray ionization-mass spectrometry

OBJECTIVE

The authors describe a rapid intraoperative ambient ionization mass spectrometry (MS) method for determining isocitrate dehydrogenase (IDH) mutation status from glioma tissue biopsies. This method offers new glioma management options and may impact extent of resection goals. Assessment of the IDH mutation is key for accurate glioma diagnosis, particularly for differentiating diffuse glioma from other neoplastic and reactive inflammatory conditions, a challenge for the standard intraoperative diagnostic consultation that relies solely on morphology.

METHODS

Banked glioma specimens (n = 37) were analyzed by desorption electrospray ionization-MS (DESI-MS) to develop a diagnostic method to detect the known altered oncometabolite in IDH-mutant gliomas, 2-hydroxyglutarate (2HG). The method was used intraoperatively to analyze tissue smears obtained from glioma patients undergoing resection and to rapidly diagnose IDH mutation status (< 5 minutes). Fifty-one tumor core biopsies from 25 patients (14 wild type [WT] and 11 mutant) were examined and data were analyzed using analysis of variance and receiver operating characteristic curve analysis.

RESULTS

The optimized DESI-MS method discriminated between IDH-WT and IDH-mutant gliomas, with an average sensitivity and specificity of 100%. The average normalized DESI-MS 2HG signal was an order of magnitude higher in IDH-mutant glioma than in IDH-WT glioma. The DESI 2HG signal intensities correlated with independently measured 2HG concentrations (R2 = 0.98). In 1 case, an IDH1 R132H-mutant glioma was misdiagnosed as a demyelinating condition by frozen section histology during the intraoperative consultation, and no resection was performed pending the final pathology report. A second craniotomy and tumor resection was performed after the final pathology provided a diagnosis most consistent with an IDH-mutant glioblastoma. During the second craniotomy, high levels of 2HG in the tumor core biopsies were detected.

CONCLUSIONS

This study demonstrates the capability to differentiate rapidly between IDH-mutant gliomas and IDH-WT conditions by DESI-MS during tumor resection. DESI-MS analysis of tissue smears is simple and can be easily integrated into the standard intraoperative pathology consultation. This approach may aid in solving differential diagnosis problems associated with low-grade gliomas and could influence intraoperative decisions regarding extent of resection, ultimately improving patient outcome. Research is ongoing to expand the patient cohort, systematically validate the DESI-MS method, and investigate the relationships between 2HG and tumor heterogeneity.

Granular cells in oligodendroglioma suggest a neoplastic change rather than a reactive phenomenon: case report with molecular characterisation

Oligodendrogliomas are diffuse gliomas characterised by IDH mutation and 1p/19q co-deletion. Classical oligodendrocytes, minigemistocytes, gliofibrillary oligodendrocytes, granular cells, and mucocytes are morphologic cell types described in oligodendroglioma. Even though the occurrence of granular cells in oligodendroglioma is known, exact nature of these cells and their molecular characteristics remain undetermined. We describe a case of oligodendroglioma with granular cells, in which we have attempted to molecularly characterise the granular cells. These granules were stained blue on Luxol fast blue and red on Masson's trichrome. The cells showed a distinct pattern of immunoreactivity to GFAP and IDH1. In addition, they exhibited mitotic activity and increased Ki-67 labelling. Molecularly, both the granular cells and classical oligodendroglial cells in the tumor showed 1p/19q co-deletion which is the diagnostic hallmark of an oligodendroglioma. Thus, we opine that granular cells are neoplastic and represent a morphological variant of neoplastic oligodendrocyte.

Mesenchymal/radioresistant traits in granular astrocytomas: evidence from a combined clinical and molecular approach

AIMS

Granular-cell astrocytomas (GCAs) are morphologically characterized by a prominent component of granular periodic acid-Schiff-positive cells, and show increased aggressiveness as compared with 'ordinary' astrocytomas. The aim of this study was to investigate, in a small series of three GCAs, the expression of mesenchymal/radioresistance-associated biomarkers [such as chitinase-3-like protein 1 (YKL-40), hepatocyte growth factor receptor (c-Met), and caveolin 1 (Cav1)] that could contribute to the poor outcome associated with this glioma subgroup.

METHODS AND RESULTS

Our results show that GCAs, according to the new molecular glioma classifications, consistently show a prognostically negative molecular trait (IDH1wt-ATRX noloss-1p/19q nocodeletion). Furthermore, GCAs significantly differed from a control series of 33 'conventional' astrocytomas, because of diffuse and strong immunohistochemical coexpression of YKL-40, c-Met, and Cav1.

CONCLUSIONS

Our findings show that specific morphological traits, such as a granular-cell component, could represent useful features in guiding the search for prognostic and predictive biomarkers that could eventually be therapy-targetable (e.g. Met inhibitors aimed at reducing radioresistance).

Diagnosis and management challenge of a granular cell astrocytoma of the pineal region: case report

Granular cell astrocytoma (GCA) is a rare type of infiltrative brain tumor with most reported cases occurring in the suprasellar region. A pineal localization is extremely rare, with only 4 previously reported cases in the literature. The authors describe the case of a 16-year-old boy who developed signs of increased intracranial pressure and Parinaud syndrome. Cranial CT and MRI revealed a well-demarcated and enhanced mass in the pineal region accompanied by obstructive hydrocephalus. Subtotal resection was performed via a subtemporal approach. A histological diagnosis of GCA was made. Three years after surgery, the patient was alive and well without adjuvant therapy, and serial MRI showed no signs of progression of a small residual tumor. After a thorough review of the different epidemiological, clinical, and imaging features; treatments; and prognoses of GCAs in other intracranial localizations, the authors analyzed features of this tumor in the pineal region.

Mistaken identity: granular cell astrocytoma masquerading as histiocytosis of the central nervous system

Granular cell astrocytoma (GCA) is an uncommon malignant glial tumour that is associated with a poor prognosis. GCA cells have some morphological and immunohistochemical similarities to macrophages. In this case, a small biopsy contained no typical astrocytoma and large rounded lesional cells were interpreted as negative for glial fibrillary acidic protein and S100 and positive for CD68, a commonly used marker for macrophages. A diagnosis of a histiocytosis was made. When the patient failed to respond to first and second line therapy, tumour resection was undertaken and the pathology then showed typical morphologic and immunohistochemical features of glioblastoma (astrocytoma World Health Organization grade IV).

Diagnostic implications of IDH1-R132H and OLIG2 expression patterns in rare and challenging glioblastoma variants

Recent work has demonstrated that nearly all diffuse gliomas display nuclear immunoreactivity for the bHLH transcription factor OLIG2, and the R132H mutant isocitrate dehydrogenase 1 (IDH1) protein is expressed in the majority of diffuse gliomas other than primary glioblastoma. However, these antibodies have not been widely applied to rarer glioblastoma variants, which can be diagnostically challenging when the astrocytic features are subtle. We therefore surveyed the expression patterns of OLIG2 and IDH1 in 167 non-conventional glioblastomas, including 45 small cell glioblastomas, 45 gliosarcomas, 34 glioblastomas with primitive neuroectodermal tumor-like foci (PNET-like foci), 23 with an oligodendroglial component, 11 granular cell glioblastomas, and 9 giant cell glioblastomas. OLIG2 was strongly expressed in all glioblastomas with oligodendroglial component, 98% of small cell glioblastomas, and all granular cell glioblastomas, the latter being particularly helpful in ruling out macrophage-rich lesions. In 74% of glioblastomas with PNET-like foci, OLIG2 expression was retained in the PNET-like foci, providing a useful distinction from central nervous system PNETs. The glial component of gliosarcomas was OLIG2 positive in 93% of cases, but only 14% retained focal expression in the sarcomatous component; as such this marker would not reliably distinguish these from pure sarcoma in most cases. OLIG2 was expressed in 67% of giant cell glioblastomas. IDH1 was expressed in 55% of glioblastomas with oligodendroglial component, 15% of glioblastomas with PNET-like foci, 7% of gliosarcomas, and none of the small cell, granular cell, or giant cell glioblastomas. This provides further support for the notion that most glioblastomas with oligodendroglial component are secondary, while small cell glioblastomas, granular cell glioblastomas, and giant cell glioblastomas are primary variants. Therefore, in one of the most challenging differential diagnoses, IDH1 positivity could provide strong support for glioblastoma with oligodendroglial component, while essentially excluding small cell glioblastoma.

Immunohistochemical and molecular genetics study of a granular cell astrocytoma: a case report of malignant transformation to a glioblastoma

We treated a 56-year-old woman who had a right temporal lobe tumor found by chance after a traffic accident. MRI confirmed a heterogeneously enhanced tumor in the temporal lobe with large peritumoral edema extending to the superior parietal lobe. The patient underwent tumor resection. The tumor consisted largely of distinct cells with discrete borders and granular cytoplasm. In granular cells, the accumulation of PAS-positive granules was observed. Immunohistochemical analysis demonstrated positive staining for GFAP, S-100, and oligodendrocyte transcription factor 2 and negative staining for synaptophysin. CD68 was negative in granular cells, but positive in stromal cells. Ki-67 labeling index was quite low. The tumor was diagnosed as a granular cell astrocytoma (GCA). Postoperative radiotherapy combined with temozolomide was administered. One month after chemoradiotherapy, the tumor occurred in the parietal lobe, and a tumorectomy was performed. The tumor was composed of poorly differentiated astrocytic tumor cells with prominent microvascular proliferation and necrosis. A small number of granular cells were locally observed and the tumor was diagnosed as a glioblastoma. O6-methylguanine-DNA methyltransferase promoter methylation was detected in the GCA but not in the glioblastoma. Isocitrate dehydrogenase mutations were not detected in either tumor. Comparative genomic hybridization analysis demonstrated that no chromosomal abnormality was found in the GCA; however, a gain of chromosomes 7 and 19 and a loss of chromosomes 10 and 9p21 (CDKN2A) were found in the glioblastoma. p53 was strongly expressed in both the GCA and glioblastoma. The tumor progressed despite extensive chemotherapy, and the patient died 1 year after the initial treatment. Our immunohistochemical, genetic and chromosomal analyses indicate that the glioblastoma was transformed from the GCA.

Multifocal epithelioid glioblastoma mimicking cerebral metastasis: case report

OBJECTIVE

Epithelioid glioblastoma is a rare morphologic subtype of glioblastoma that closely mimics metastatic carcinoma or metastatic melanoma histologically. All previous case reports of this unusual glioblastoma variant have been solitary lesions. We report here the first case to our knowledge of multifocal epithelioid glioblastoma mimicking cerebral metastasis.

CLINICAL PRESENTATION

A 67-year-old man with a prior history of mycosis fungoides, a common form of cutaneous T-cell lymphoma, presented with memory loss and impaired peripheral vision. Two discrete brain lesions highly suspicious for metastases were identified by magnetic resonance imaging (MRI).

INTERVENTION

The patient underwent two separate craniotomies; both lesions were successfully resected in toto with an excellent post-surgical outcome.

CONCLUSION

Epithelioid glioblastoma is one of the rarest morphologic subtypes of glioblastoma. Here we describe the first case to our knowledge of multifocal epithelioid glioblastoma that convincingly mimicked a secondary metastatic process. Multifocal epithelioid glioblastoma should be included in the differential diagnosis of patients who present with multiple discrete brain lesions. An attempt at gross total resection is recommended when anatomically feasible for definitive histopathological diagnosis and to improve progression free survival of patients who present with similarly ambiguous and potentially misleading multiple lesions.