UNASSIGNED: Glioma is the most common primary intracranial neoplasm with a relatively poor prognosis.
UNASSIGNED: Here, we present a unique case of a 53-year-old woman with two histopathologically distinct gliomas at the initial diagnosis. She presented with headaches and left limb weakness before admission, and magnetic resonance imaging (MRI) showed right frontal and basal ganglia area involvement combined with hemorrhage. The patient underwent a navigation-guided craniotomy for tumor removal. Pathological examination revealed the right frontal lobe lesion as a WHO grade II IDH-NOS astrocytoma, but the right parietal lobe lesion was a WHO grade IV IDH-mutant diffuse astrocytoma. Molecular detection of the parietal lesion revealed a point mutation at the R132 locus of the IDH1 gene, no mutation in the TERT promoter, amplification of the epidermal growth factor receptor, and a non-homozygous CDKN2A/B deletion.
UNASSIGNED: In-depth epigenomic analysis and molecular examination revealed that one patient had two different brain tumors, underscoring the importance of performing a comprehensive brain tumor workup.
UNASSIGNED: This unique case confirms that adjacent astrocytomas may have different molecular pathogenesis and provides novel insights into the development of gliomas.

Rishan Thimma SudarsanGlioblastoma are known for its aggressive intracranial course of disease, where the overall survival is less than 18 months. Of late, the World Health Organization has reclassified and renamed secondary glioblastomas as isocitrate dehydrogenase (IDH)-mutant grade 4 astrocytomas, which is relatively better than its IDH wild-type counterpart; however, overall survival remains poor. In such tumors, metastases outside the craniospinal neuraxis is very rare, and does sometimes present with symptoms which create a diagnostic dilemma and arriving at such diagnosis is still challenging even for the best of the clinicians worldwide. Here we present such a rare case scenario, where a grade 4 astrocytoma that has transformed from a low-grade glioma, presenting with bone metastases, its workup, treatment, and various possible mechanisms underlying such a rare event, and the need of such clinical scenario especially long-term survivors to be wary of distant metastases.

Chondrosarcomas are primary malignant bone tumor that rarely occurs in the head and neck region. Squash cytology of skull base neoplasm shows atypical chondrocytes and myxoid stroma, which suggests many possibilities like chordoma, chordoid glioma, chordoid meningioma and chondrosarcoma. Isocitrate dehydrogenase gene (IDH) mutations have been reported in 50% to 60% of the head and neck region chondrosarcoma.
A 37-year-old female came to the outpatient department and complaint of difficulty in walking and swaying to the right side for one year. The radiology was suggestive of right-sided trigeminal schwannoma. However, the squash cytology showed the presence of necrosis, and pink to bluish-coloured myxoid stroma. The tumor cells were pleomorphic and had a hyperchromatic nucleus, hyalinized condensed to granular cytoplasm. The histopathological examination of intraoperative soft tissue showed the presence of cellular lobules of atypical chondrocytes arranged in the myxoid background. The features were of Chondrosarcoma. No parenchymal invasion was found.
This case report aims to create awareness about a rare tumor, which rarely forms a differential diagnosis for skull base neoplasms. As chondrosarcoma are immunoreactive to IDH1 so this marker can be useful in clinching the diagnosis in conjunction with other immunohistochemical markers in a small biopsy from skull base neoplasms.

Dedifferentiated chondrosarcoma (DDCS) is a rare entity, constituting only 1-2% of all primary bone tumors, and has a dismal prognosis. Nearly two-thirds of the primary tumors of DDCSs are found in the appendicular skeleton, mostly involving the femur, humerus, and pelvis. DDCS of the small bones of the hand and foot are exceedingly rare with only four cases documented in the literature so far. In this report, we present a case of a 91-year-old woman with a rapidly growing bone tumor initially thought to be a trigger finger, which, on histologic examination of the amputation, turned out to be DDCS. On a follow-up CT scan, multiple pulmonary metastases were identified. Next-generation sequencing identified isocitrate dehydrogenase 2 (IDH2) (p.R172S, c.516G>T), TERT (c.-146C>T), and TP53 (c.559+1G>A) mutations. Microsatellite instability was equivocal and tumor mutation burden was low. Due to the advanced age of the patient, she was given palliative treatment and was alive at the six-month follow-up.

BACKGROUND: Adult brainstem gliomas are rare entities that demonstrate heterogeneous biology and appear to be distinct from both their pediatric counterparts and adult supratentorial gliomas. Although the role of histone 3 mutations is being increasingly understood in this disease, the effect of isocitrate dehydrogenase (IDH) mutations remains unclear, largely because of limited data.
METHODS: The authors present the case of a 29-year-old male with an IDH1-mutant, World Health Organization grade III anaplastic astrocytoma in the dorsal medulla, and they provide a review of the available literature on adult IDH-mutant brainstem glioma. The authors have amassed a cohort of 15 such patients, 7 of whom have survival data available. Median survival is 56 months in this small cohort, which is similar to that for IDH wild-type adult brainstem gliomas.
CONCLUSIONS: The authors\' work reenforces previous literature suggesting that the role of IDH mutation in glioma differs between brainstem and supratentorial lesions. Therefore, the authors advocate that adult brainstem gliomas be studied in terms of major molecular subgroups (including IDH mutant) because these gliomas may exhibit fundamental differences from each other, from pediatric brainstem gliomas, and from adult supratentorial gliomas.

BACKGROUND: Periosteal chondrosarcomas are among the rarest types of chondrosarcomas dealt with in few small series of cases. In this study, we aimed to present our experience with this chondrosarcoma, seek for prognostic factors for OS and DFS and survey the status of IDH1 and IDH2.
RESULTS: 55 periosteal chondrosarcomas were retrospectively identified. Median age was 37 years, there was a male predominance (62%). The great majority of cases involved the metaphysis of long bones of the extremities. The median size of the tumors was 7.5 cm. Thirty patients underwent to subtotal surgical resection, 22 to tangential resection and the remaining 3 to amputation. The margins, reported in 54 cases, were wide/radical in 38 patients (70.4%), marginal in 9 (16.7%) and intralesional in 7 (12.9%). Histologically, 23 (42%) were grade 1; 27 (49%), grade 2; 3 (5%), grade 3 and 2 (4%) were dedifferentiated. A third of cases in which mutational analysis was feasible harbored heterozygous mutations in codon 132 of IDH1. Fifty-four cases were included for follow-up (median, 137 months). Four patients had local recurrences and six patients developed metastasis to the lungs. All patients that developed metastasis died of disease, two died of unrelated causes and 46 were alive without disease. OS and DFS was not found to be statistically associated with clinical and pathological parameters considered.
CONCLUSIONS: periosteal chondrosarcomas exhibit a low-grade behavior that can be adequately treated with marginal excisions. Clinical and morphologic parameters do not seem to predict their outcome.