Clinical, pathological, and molecular features of central nervous system tumors with BCOR internal tandem duplication.

Central nervous system tumor with BCOR internal tandem duplication (CNS tumor with BCOR-ITD) constitutes a molecularly distinct entity, characterized by internal tandem duplication within exon 15 of the BCOR transcriptional co-repressor gene (BCOR-ITD). The current study aimed to elucidate the clinical, pathological, and molecular attributes of CNS tumors with BCOR-ITD and explore their putative cellular origin. This study cohort comprised four pediatric cases, aged 23 months to 13 years at initial presentation. Magnetic resonance imaging revealed large, well-circumscribed intra-CNS masses localized heterogeneously throughout the CNS. Microscopically, tumors were composed of spindle to ovoid cells, exhibiting perivascular pseudorosettes and palisading necrosis, but lacking microvascular proliferation. Immunohistochemical staining showed diffuse tumor cell expression of BCOR, CD56, CD99, vimentin, and the stem cell markers PAX6, SOX2, CD133 and Nestin, alongside focal positivity for Olig-2, S100, SOX10, Syn and NeuN. Molecularly, all cases harbored BCOR-ITDs ranging from 87 to 119 base pairs in length, including one case with two distinct ITDs. Notably, the ITDs were interrupted by unique 1-3 bp insertions in all cases. In summary, CNS tumors with BCOR-ITD exhibit characteristic clinical, pathological, and molecular features detectable through BCOR immunohistochemistry and confirmatory molecular analyses. Their expression of stem cell markers raises the possibility of an origin from neuroepithelial stem cells rather than representing true embryonal neoplasms.

A Rare Case of Breast fat-Forming Solitary Fibrous Tumor With Molecular Confirmation.

Solitary fibrous tumor (SFT) is an uncommon fibroblastic neoplasm which may arise in a wide range of anatomic location and can occur across all ages. Fat-forming SFT is a rare morphological variant of SFT. Primary breast fat-forming SFT is exquisitely rare. Here, we report a case in a 51-year-old Chinese woman with a palpable painless mass in the left breast. A color Doppler ultrasound scan examination demonstrated a 3.4-cm oval, well-circumscribed, hypoechoic solid mass with several peripheral and internal color flow signals. Magnetic resonance imaging (MRI) showed a focal lobulated solid nodular lesion displaying geographical enhancement but no architectural distortion. Subsequently, she underwent a left breast lumpectomy. In histopathologic examination, there was a well-circumscribed, cellular spindle cell tumor consisting of short fascicles of bland, fusiform, ovoid to spindle cells disposed in a patternless architecture around branching vascular spaces within a fibrous stroma with wispy collagen. Cells revealed mild nuclear atypia. Mitotic figures were up to 4/10 high-power fields (HPFs) in the hot spot. Mature adipocytes intermixed with spindle cells were also observed. The tumor cells were diffusely positive for CD34 and STAT6. Some S100-expressing adipocytes co-expressed STAT6. Next-generation sequencing (NGS) revealed the presence of the NAB2exon6::STAT6exon2 fusion. The histological, immunohistochemical (IHC) and molecular examinations confirmed the diagnosis of fat-forming SFT. Post-excision, the patient showed no signs of tumor recurrence or metastasis in a 7-month follow-up. Here, we describe a rare case of a fat-forming SFT involving the breast and highlight the comprehensive pathological evaluation and necessary ancillary testing.

Elevated Kir2.1/nuclear N2ICD defines a highly malignant subtype of non-WNT/SHH medulloblastomas.

Medulloblastoma (MB) is one of the most common childhood malignant brain tumors (WHO grade IV), traditionally divided into WNT, SHH, Group 3, and Group 4 subgroups based on the transcription profiles, somatic DNA alterations, and clinical outcomes. Unlike WNT and SHH subgroup MBs, Group 3 and Group 4 MBs have similar transcriptomes and lack clearly specific drivers and targeted therapeutic options. The recently revised WHO Classification of CNS Tumors has assigned Group 3 and 4 to a provisional non-WNT/SHH entity. In the present study, we demonstrate that Kir2.1, an inwardly-rectifying potassium channel, is highly expressed in non-WNT/SHH MBs, which promotes tumor cell invasion and metastasis by recruiting Adam10 to enhance S2 cleavage of Notch2 thereby activating the Notch2 signaling pathway. Disruption of the Notch2 pathway markedly inhibited the growth and metastasis of Kir2.1-overexpressing MB cell-derived xenograft tumors in mice. Moreover, Kir2.1high/nuclear N2ICDhigh MBs are associated with the significantly shorter lifespan of the patients. Thus, Kir2.1high/nuclear N2ICDhigh can be used as a biomarker to define a novel subtype of non-WNT/SHH MBs. Our findings are important for the modification of treatment regimens and the development of novel-targeted therapies for non-WNT/SHH MBs.

Papillary Solitary Fibrous Tumor/Hemangiopericytoma: An Uncommon Morphological Form With NAB2-STAT6 Gene Fusion.

Solitary fibrous tumor/hemangiopericytomas (SFT/HPCs) are mesenchymal tumors characterized by "staghorn" blood vessels and collagen deposition. Little is known about SFT/HPCs with papillary architecture. We summarized the clinicopathologic features of 12 patients with papillary SFT/HPCs (8 males and 4 females; median age: 59 years), including 8 previously reported cases. Tumors were present in the meninges (75%, 9/12), adrenal gland (8%, 1/12), orbit (8%, 1/12), or spinal canal (8%, 1/12). Six tumors (50%) had a true papillary architecture with fibrovascular cores and 6 tumors (50%) had a pseudopapillary architecture with vascular cores. Nuclear staining for STAT6 was present in all tested tumors (10/10). RT-PCR indicated NAB2 ex6-STAT6 ex17 fusion in 4 tumors (80%, 4/5) and NAB2 ex4-STAT6 ex2 fusion in 1 tumor (20%, 1/5). Five patients (42%, 5/12), all with tumors in the meninges, developed local recurrence at a median of 61 months after surgery (range: 56-165 months; mean: 88.6 months). These results indicated that the papillary architecture is a morphological form of SFT/HPCs. The recognition of this pattern, with appropriate immunohistochemical analysis and assessment of NAB2-STAT6 fusion, should facilitate the distinction of these rare neoplasms from morphologically similar tumors in the meninges, lung, pleura, and soft tissue.

Clinical, radiological features and surgical strategies for 23 NF1 patients with intraorbital meningoencephalocele.

Intraorbital meningoencephalocele is a rare manifestation of neurofibromatosis type 1 (NF1) caused by secondary changes in sphenoid dysplasia, and it seriously affects patients' vision and facial appearance. We retrospectively analyzed the clinical data of 23 patients with NF1 and intraorbital meningoencephalocele, summarized the surgical strategies employed, and evaluated their clinical efficacy in order to better understand its management in clinical practice, establish a reasonable surgical strategy, and assess prognosis. Before surgery, 22 patients had unilateral pulsatile exophthalmos, 18 patients had significant visual impairment, and 13 patients had ptosis associated with an orbital plexiform neurofibroma (PNF). All 23 patients underwent microsurgical craniotomy with skull base reconstruction using a soft titanium mesh. One month after surgery, the degree of exophthalmos in the 22 (95.65%) patients was significantly reduced compared with before surgery (P < 0.001), and ocular pulsation had subsided. The visual acuity did not decrease significantly (P = 0.298) compared with before surgery. Eleven (47.83%) patients received phase-II eyelid PNF resection and/or oculoplastic surgery, and the degree of ptosis was significantly reduced (P < 0.001). There was no recurrence of pulsatile exophthalmos, displacement of titanium mesh, decreased visual acuity, or increased degree of ptosis noted during follow-up. The best strategy is to reconstruct the skull base under microscopy to relieve pulsating exophthalmos and preserve existing visual function. In cases of ptosis caused by an eyelid PNF, surgical resection should be performed as soon as possible to remove the tumor, and/or oculoplastic surgery should be performed to improve the cosmetic outcome.

Aberrant expression of thyroid transcription factor-1 in schwannomas.

Aberrant expression of thyroid transcription factor-1 (TTF-1) has been observed in tumors arising in locations other than thyroid gland, lung and ventral forebrain. However, TTF-1 expression in schwannomas has not yet been studied. Meanwhile, a few inconsistent changes in protein expression have been identified between schwannomas and other peripheral nerve sheath tumors. We evaluated TTF-1 expression in 161 schwannomas and 43 other peripheral nervous system lesions, including ganglioneuromas (n = 8), malignant peripheral nerve sheath tumors (MPNSTs) (n = 11), neurofibromas (n = 24), and traumatic neuromas (n = 9), using immunohistochemistry and verified it using quantitative real-time reverse-transcription polymerase chain reaction (qPCR) to explore TTF-1 expression in peripheral nervous system lesions. Formalin-fixed paraffin-embedded (FFPE) tissues were obtained for both analyses. In this study, we observed nuclear TTF-1 staining in 109 (67.7%) schwannomas, including 102 of 131 (77.9%) conventional, 1 of 20 (5.0%) cellular and 6 of 10 (60.0%) plexiform schwannomas. Nuclear staining was not observed in normal peripheral nerves and non-schwannoma lesions. qPCR verified the aberrant expression and revealed a correlation between TTF-1 protein and mRNA levels (r = 0.633, P = .003). In conclusion, the data from our study show that TTF-1 is selectively expressed in the majority of schwannomas, particularly the conventional variants. Based on this observation, the TTF-1 protein and mRNA are specifically expressed in schwannomas. This highly aberrant expression of varying amounts of TTF-1 may provide new clues to reveal the pathogenesis of schwannoma.

[Exploration of the association of H. pylori and EBV infection with cardiac and distal gastric adenocarcinoma among residents in Cixian County, a high-risk area of esophgeal cancer in Hebei province].

OBJECTIVE: To evaluate the H. pylori and Epstein-Barr virus infection in cardiac and distal gastric adenocarcinoma tissues in residents in Cixian county, a high risk area of esophageal cancer in Hebei province, and to explore the putative role of H. pylori and Epstein-Barr virus infection in the carcinogenesis of adenocarcinoma at different subsites of stomach. METHODS: H. pylori and Epstein-Barr virus latent membrane protein 1 (EBV-LMP1) immunopositivities were determined by Elivision(TM) plus immunohistochemical staining in 190 gastric adenocarcinoma tissues including 144 cases of cardiac adenocarcinoma and 46 cases of distal gastric adenocarcinoma. The relationship between H. pylori and Epstein-Barr virus infection and the subsite, Laurén type as well as other clinicopathological features of gastric adenocarcinoma were analyzed. RESULTS: No significant difference was found between the H. pylori detection rates in cardiac and distal gastric adenocarcinomas(56.9% vs. 65.2%, P > 0.05). The detection rate of H. pylori in intestinal type was significantly higher than that in the diffuse type distal gastric adenocarcinomas (71.8% vs. 28.6%, P < 0.05). No positive expression of EBV-LMP1 was found in the gastric adenocarcinomas in this study. CONCLUSIONS: No significant differences in H. pylori and EBV-LMP1 infections were found between cardiac and distal gastric adenocarcinomas in Cixian county. H. pylori infection is related with the intestinal type of distal gastric adenocarcinoma.