Animals ; Humans ; Lung Neoplasms ; metabolism ; pathology ; Neoplastic Stem Cells ; pathology

Objective:To analyze the clinical features and mutation of myeloid differentiation factor 88 (MYD88) L265P in patients with diffuse large B-cell lymphoma (DLBCL) of central nervous system (CNS).Methods:The clinicopathological materials of 45 cases of DLBCL of CNS were retrospectively collected in Xuanwu Hospital, Capital Medical University from September 2014 to February 2017. The clinicopathological data were retrospectively analyzed, combined with immunohistochemistry, EB virus in situ hybridization, imaging and medical history. The mutation of MYD88 L265P gene was detected by pyrosequencing and its clinical significance was analyzed. Results:The age of the patients ranged from 42 to 82 years [(57.6±8.8) years], including 24 males and 21 females. Totally 93.3% (42/45) of the patients had supratentorial tumours, which were single or multiple. The cerebral hemisphere (31/45, 68.9%) was the most common involved site, and 21 cases (21/45, 46.7%) had multiple lesions. Histologically, DLBCL in the CNS showed diffuse infiltration of tumor tissue, some of which grew around blood vessels in a "sleeve" arrangement. CD 20 and CD 79a were diffusely and strongly positive. Thirty-nine cases (39/45, 86.7%) were non-germinal center B cell (non-GCB) subtype and 6 cases (6/45, 13.3%) were germinal center B cell (GCB) subtype. MYD88 L265P mutation was found in 64.4% (29/45) patients. There was statistically significant difference between non-GCB type (71.8%, 28/39) and GCB type DLBCL (1/6, P=0.017). Compared with the operation/biopsy group without chemotherapy, operation+chemotherapy, biopsy+chemotherapy, operation/biopsy+chemotherapy+stem cell transplantation can improve the survival and prognosis ( HR=0.05, 95% CI 0.01-0.33 , P=0.002; HR=0.04, 95% CI 0.01-0.36 , P=0.004; HR=0.01, 95% CI 0.00-0.17 , P=0.001; respectively). Conclusions:DLBCL of the CNS is aggressive tumor with poor prognosis, the clinical manifestations are complex and diverse, and the diagnosis is challenging. MYD88 L265P is a common and specific gene mutation in primary CNS lymphoma(PCNSL), which is of great significance in the diagnosis and treatment of lymphoma. The MYD88 L265P mutation was more frequently detected in non-GCB than GCB subtype. Chemotherapy can improve the survival rate of PCNSL patients. If chemotherapy achieves complete remission and autologous hematopoietic stem cell transplantation is performed, there may be a chance of long-term survival.

Objective:To analyze the clinicopathological features and probable mechanisms of high-grade gliomas with H3 G34R mutation.Methods:Five cases of high-grade gliomas with H3 G34R mutation were collected at Xuanwu Hospital, Capital Medical University, Beijing, China, from 2016 to 2019. The clinical and pathological data for each case was retrospectively reviewed.Results:The 5 patients (2 males and 3 females) aged from 15 to 45 years (mean 23 years), and had a history of headache or motor weakness. Four of them were younger than 20 years of age. Magnetic resonance imaging showed that the lesions of 3 cases were seen separately in frontal lobe, parietal lobe or temporal lobe, 1 case involved both frontal lobe and parietal lobe, and otherwise multiple lobes were involved in 1 case. Contrast enhancement could be observed in 2 cases. Pathological examination showed that glioblastoma was the most common entity, with or without primitive neuronal component. All 5 cases showed that H3 G34R was diffusely positive in tumor nuclei with ATRX loss. Moreover, p53 was overexpressed in 4 cases. None of them showed Olig2 expression. Two patients showed disease progression after surgery at 18 months and 24 months, respectively. The latter of the two deceased 3 months after tumor progression.Conclusions:The clinicopathological and molecular genetics features of high-grade gliomas with H3 G34R mutation have relatively similar clinicopathological and genetic features, and more commonly seen in young adults (vs. older adults). Thus, these tumors may be discussed further as a distinct tumor entity.

Objective:To analyze the clinicopathological and molecular features and prognostic implications of adult isocitrate dehydrogenase wild type (IDH-wt) diffuse gliomas.Methods:A total of 87 cases of adult IDH-wt diffuse gliomas from 2016 to 2020 in Xuanwu Hospital of Capital Medical University were retrospectively collected. The clinicopathological characteristics and prognosis were analyzed. Molecular characteristics were also analyzed using Sanger sequencing and next generation sequencing.Results:There were 53 males and 34 females, aged from 19 to 78 years (mean 53 years). Histopathologically, there were 63 (72.4%) glioblastomas, 16 (18.4%) anaplastic astrocytomas, six (6.9%) diffuse astrocytomas, and one (1.1%) each of anaplastic oligodendrocytoma, and anaplastic oligodendroglioma. Common molecular genetic changes in IDH-wt gliomas included TERT promoter mutation which was found in 60 cases (69.0%); MGMT promoter methylation in 43 cases (49.4%); EGFR mutation in 38 cases (43.7%); PTEN mutation in 35 cases (40.2%) and TP53 mutation in 32 cases (36.8%). In addition, PDGFRA mutation was detected in 17 cases (19.5%), CDK4 amplification in 15 cases (17.2%) and MDM2 amplification in 11 cases (12.6%). In IDH-wt diffuse gliomas, there was no significant difference in the overall survival between TERT promoter, EGFR, PTEN, TP53, PDGFRA, CDK4, MDM2 mutations and the wild-type, since these gene mutations could co-occur in any case ( P>0.05). Also there was no significant difference in the overall survival between the WHO grade Ⅱ/Ⅲ gliomas and glioblastoma patients with these gene mutations ( P>0.05). Conclusions:TERT promoter, EGFR, PTEN, TP53, PDGFRA, CDK4 and MDM2 gene mutations are common molecular genetic changes in adult IDH-wt gliomas, and are associated with poor prognosis. It is suggested that these genes are potentially useful for predicting the prognosis and should be tested in adult IDH-wt gliomas.

Objective:To examine whether immunohistochemistry of methylthioadenosine phosphorylase (MTAP) and p16 could be used to predict the CDKN2A status in various brain tumors.Methods:A total of 118 cases of IDH-mutant astrocytomas, 16 IDH-wildtype glioblastoma, 17 polymorphic xanthoastrocytoma (PXA) and 20 meningiomas diagnosed at Xuanwu Hospital, Capital Medical University, Beijing, China from November 2017 to October 2023 were collected and analyzed. The CDKN2A status was detected by using fluorescence in situ hybridization or next-generation sequencing. Expression of MTAP and p16 proteins was detected with immunohistochemistry. The association of loss of MTAP/p16 expression with CDKN2A homozygous/heterozygous deletion was examined.Results:Among the 118 cases of IDH-mutant astrocytoma, 13 cases showed homozygous deletion of CDKN2A. All of them had no expression of MTAP while 9 cases had no expression of p16. Among the 16 cases of IDH wild-type glioblastoma, 6 cases showed homozygous deletion of CDKN2A. All 6 cases had no expression of MTAP, while 3 of these cases had no expression of p16 expression. Among the 17 PXA cases, 4 cases showed homozygous deletion of CDKN2A, and the expression of MTAP and p16 was also absent in these 4 cases. Among the 20 cases of meningiomas, 4 cases showed homozygous deletion of CDKN2A. Their expression of MTAP and p16 was also absent. Among the four types of brain tumors, MTAP was significantly correlated with CDKN2A homozygous deletion ( P<0.05), with a sensitivity of 100%. However, it was only significantly correlated with the loss of heterozygosity (LOH) of CDKN2A in astrocytomas ( P<0.001). P16 was associated with CDKN2A homozygous deletion in IDH-mutant astrocytoma and PXA ( P<0.001), but not with the LOH of CDKN2A. Its sensitivity and specificity were lower than that of MTAP. Conclusions:MTAP could serve as a predictive surrogate for CDKN2A homozygous deletion in adult IDH-mutant astrocytoma, PXA, adult IDH-wildtype glioblastoma and meningioma. However, p16 could only be used in the first two tumor types, and its specificity and sensitivity are lower than that of MTAP.