PAX3/7 fusion-negative rhabdomyosarcoma (FN-RMS) is a childhood mesodermal lineage malignancy with a poor prognosis for metastatic or relapsed cases. Limited understanding of advanced FN-RMS is partially attributed to the absence of sequential invasion and dissemination events and the challenge in studying cell behavior, using, for example, non-invasive intravital microscopy (IVM), in currently used xenograft models. Here, we developed an orthotopic tongue xenograft model of FN-RMS to study cell behavior and the molecular basis of invasion and metastasis using IVM. FN-RMS cells are retained in the tongue and invade locally into muscle mysial spaces and vascular lumen, with evidence of hematogenous dissemination to the lungs and lymphatic dissemination to lymph nodes. Using IVM of tongue xenografts reveals shifts in cellular phenotype, migration to blood and lymphatic vessels, and lymphatic intravasation. Insight from this model into tumor invasion and metastasis at the tissue, cellular, and subcellular level can guide new therapeutic avenues for advanced FN-RMS.

Intrahepatic cholangiocarcinoma (ICC) is a lethal cancer with poor survival especially when it spreads. The histopathology of its rare intraductal papillary neoplasm of the bile duct type (IPNB) characteristically shows cancer cells originating within the confined bile duct space. These cells eventually invade and infiltrate the nearby liver tissues, making it a good model to study the mechanism of local invasion, which is the earliest step of metastasis. To discover potential suppressor genes of local invasion in ICC, we analyzed the somatic mutation profiles and performed clonal evolution analyses of the 11 pairs of macrodissected locally invasive IPNB tissues (LI-IPNB) and IPNB tissues without local invasion from the same patients. We identified a protein-truncating variant in an E3 ubiquitin ligase, RNF213 (c.6967C>T; p.Gln2323X; chr17: 78,319,102 [hg19], exon 29), as the most common protein-truncating variant event in LI-IPNB samples (4/11 patients). Knockdown of RNF213 in HuCCT1 and YSCCC cells showed increased migration and invasion, and reduced vasculogenic mimicry but maintained normal proliferation. Transcriptomic analysis of the RNF213-knockdown vs control cells was then performed in the HuCCT1, YSCCC, and KKU-100 cells. Gene ontology enrichment analysis of the common differentially expressed genes revealed significantly altered cytokine and oxidoreductase-oxidizing metal ion activities, as confirmed by Western blotting. Gene Set Enrichment Analysis identified the most enriched pathways being oxidative phosphorylation, fatty acid metabolism, reactive oxygen species, adipogenesis, and angiogenesis. In sum, loss-of-function mutation of RNF213 is a common genetic alteration in LI-IPNB tissues. RNF213 knockdown leads to increased migration and invasion of ICC cells, potentially through malfunctions of the pathways related to inflammation and energy metabolisms.

UNASSIGNED: Solid pseudopapillary neoplasms (SPNs) of the pancreas are uncommon, low-malignancy neoplasms. Moreover, the occurrence of extrapancreatic SPNs is rarely encountered.
UNASSIGNED: A 45-year-old female presented with a right upper abdominal mass and abdominal pain for 3 and 1 months as chief complaints, respectively. Initially, the patient was misdiagnosed with hepatocellular carcinoma based on her symptoms and results of physical and imaging examinations. Following multidisciplinary discussion and ruling out surgical contraindications, a decision was taken to proceed with surgical intervention. Interestingly, the tumor was found to originate from the retroperitoneum and had invaded the right half of the liver and the right wall of the inferior vena cava. The operation was uneventful, and the pathological findings confirmed the tumor as an extrapancreatic SPN. The patient remained asymptomatic after 15 months of follow-up.
UNASSIGNED: Surgical treatment remains the preferred option for extrapancreatic SPN. The preoperative misdiagnosis also highlights the importance of accurate diagnosis and the development of appropriate treatment strategies for liver masses.

The aim of this study was to explore the influencing factors that affect the local invasive behavior of thymic epithelial tumors (TETs).
We retrospectively analyzed 524 patients with TETs who underwent surgical treatment at our center from January 2010 to January 2022. Cox regression analysis was applied to identify predictors associated with the prognosis of TET. Logistic regression analysis was used to analyze the factors associated with the locally invasive behavior of TETs. Receiver operating characteristic analysis and the Youden index were applied to determine the predictive efficiency and cutoff value.
There were 275 males and 249 females with a median age of 56 years. Seventy-seven patients had locally invasive behavior. The prognosis of local invasive TETs was significantly worse that of noninvasive TETs (P < 0.001). WHO classification and tumor size were two hazard factors for tumor invasive behavior. The risk of local invasion increased by 2.196 (OR (95 % CI): 1.813-2.659) times for each grade in WHO classification with a change from type A to thymic carcinoma. The tumor size cutoff of 6 cm represented a distinct boundary in predicting the hazard of local invasion (AUC: 0.784, specificity: 0.711, sensitivity: 0.726).
WHO classification and tumor size are important factors in predicting the locally aggressive behavior of TETs. The invasion capability of TETs is constantly increasing with an escalation in WHO classification. Tumors greater than 6 cm in size have a higher risk for local invasion.

Inflammatory myofibroblastic tumors (IMT) are rare spindle cell neoplasms derived from mesenchymal cells. Primary genitourinary IMTs share morphological and molecular features with various malignant spindle cell sarcomas, which introduces a diagnostic challenge. We present the case of a 50-year-old female who was referred for evaluation of hematuria and nonspecific urinary symptoms and was found to have a mass originating from the urinary bladder that involved the cervix and right ovary. Transurethral resection of bladder tumor (TURBT) and immunohistochemical analysis revealed an IMT. To our knowledge, this is the first documented case of primary genitourinary IMT with cervical and ovarian involvement.

A giant basal cell carcinoma (GBCC) is a rare variant of basal cell carcinoma (BCC) that is larger (>5 cm) and more aggressive. While BCC is usually surgically excised as a small, local tumor, cases of GBCC represent a considerable portion of BCC malignancies and mortality. The growth of GBCC is hypothesized to be multifactorial, and due to the successful treatment of BCC, available data is limited. We present a case of GBCC found during routine post-mortem dissection in a 92-year-old male cadaver. The neoplasm showed predilection to periauricular soft tissue invasion, despite demonstrating high-risk characteristics for metastasis. Microscopic analysis demonstrated an infiltrative growth pattern and neurotropism. Perineural spread could be observed on gross dissection, indicating a worse prognosis, but there was no evidence of lymphatic or hematogenous spread. This is most likely due to the stromal dependence of BCC. Local invasion of the primary tumor likely compromised head and neck function, but there was no secondary tumor evidence. There were no histopathological findings that indicate an aggressive growth or metastatic transformation of the tumor. Therefore, while a conclusion about duration cannot be made due to the anonymity of the cadaver, duration of growth likely was a significant factor in mortality.

Gastric cancer is a tumor type characterized by lymph node metastasis and the invasion of local tissues. There is thus a critical need to clarify the molecular mechanisms governing gastric cancer onset and progression to guide the treatment of this disease. Long non-coding RNAs and mRNA expression profiles associated with early and local advanced gastric cancer were examined through microarray analyses, with GO and KEGG analyses being employed as a means of exploring the functional roles of those long non-coding RNAs and mRNAs that were differentially expressed in gastric cancer. In total, 1005 and 1831 lncRNAs and mRNAs, respectively, were found to be differentially expressed between early and local advanced gastric cancer. GO and KEGG analyses revealed several pathways and processes that were dysregulated, including the RNA transport, ECM-receptor interaction, and mRNA splicing pathways. In co-expression networks, E2F1, E2F4, and STAT2 were identified as key transcriptional regulators of these processes. Moreover, thrombospondin-2 was confirmed as being expressed at high levels in more advanced gastric cancer by both the GEO and TCGA databases. RNA-sequencing analyses of SGC-790 cells transfected to express thrombospondin-2 further revealed this gene to enhance NF-kB and TNF pathway signaling activity. These results offer insight into gastric cancer-related regulatory networks and suggest thrombospondin-2 to be an important oncogene that drives the progression of this deadly cancer type.

To summarize the characteristics of local extension of eccentric and central nasopharyngeal carcinoma (NPC) by magnetic resonance imaging (MRI) and to improve clinical target volume (CTV) delineation.
MRI of 870 newly diagnosed NPC patients were reviewed. According to tumor distribution features, the NPCs were divided into eccentric and central lesions.
All local invasions presented as continuous invasion from gross lesions and structures adjacent to the nasopharynx were more likely to be invaded. There were 240 (27.6%) and 630 (72.4%) cases with central and eccentric lesions, respectively. The spread of eccentric lesions was centered on the ipsilateral Rosenmüller\'s fossa; and most anatomic sites had significantly higher invasion rates in the ipsilateral side than the contralateral side (P < 0.05). However, they were at low risk of concurrent bilateral tumor invasion (<10%), except the prevertebral muscle (15.4%) and nasal cavity (13.8%). The extension of central NPCs was centered on the nasopharyngeal superior-posterior wall and was more common in the superior-posterior direction. Furthermore, bilateral tumor invasion into the anatomical sites was common.
Local invasion of NPC was characterized by continuous invasion from proximal to distal sites. The eccentric and central lesions showed different invasion features. Individual CTV delineation should be based on the distribution characteristics of tumors. The eccentric lesions had a very low probability of invasion into the contralateral tissue; thus routine prophylactic radiation of contralateral parapharyngeal space and skull base foramina may not be necessary.