Chordoma and chondrosarcoma share common radiographic characteristics yet are distinct clinically. A radiomic machine learning model differentiating these tumors preoperatively would help plan surgery. MR images were acquired from 57 consecutive patients with chordoma (N = 32) or chondrosarcoma (N = 25) treated at the University of Tokyo Hospital between September 2012 and February 2020. Preoperative T1-weighted images with gadolinium enhancement (GdT1) and T2-weighted images were analyzed. Datasets from the first 47 cases were used for model creation, and those from the subsequent 10 cases were used for validation. Feature extraction was performed semi-automatically, and 2438 features were obtained per image sequence. Machine learning models with logistic regression and a support vector machine were created. The model with the highest accuracy incorporated seven features extracted from GdT1 in the logistic regression. The average area under the curve was 0.93 ± 0.06, and accuracy was 0.90 (9/10) in the validation dataset. The same validation dataset was assessed by 20 board-certified neurosurgeons. Diagnostic accuracy ranged from 0.50 to 0.80 (median 0.60, 95% confidence interval 0.60 ± 0.06%), which was inferior to that of the machine learning model (p = 0.03), although there are some limitations, such as the risk of overfitting and the lack of an extramural cohort for truly independent final validation. In summary, we created a novel MRI-based machine learning model to differentiate skull base chordoma and chondrosarcoma from multiparametric signatures.

Human coenurosis is caused by the larval stages of Taenia species, mainly Taenia multiceps and Taenia serialis. T. multiceps has been reported to cause human central nervous system (CNS) infections, but no CNS case caused by T. serialis has been reported. The authors report the first case of human neurocoenurosis caused by T. serialis, which was confirmed by mitochondrial DNA analysis. A 38-year-old man presented with visual disturbance and headache, and subsequent magnetic resonance imaging (MRI) revealed a ring-enhancing cystic lesion in the left occipital lobe. Biopsy was performed, and the resultant histopathological diagnosis was that of low-grade B-cell lymphoma. Chemotherapy was initiated, but a subsequent MRI showed increased ring enhancement. Due to the unexpected clinical course, a surgical resection of the lesion was performed. The lesion was completely removed. Pathological examination showed multiple scolices with hooklets, suckers, and numerous calcareous corpuscles. Therefore, the diagnosis of neurocysticercosis was made. However, mitochondrial DNA analysis showed that the disease was definitively coenurosis caused by T. serialis. Albendazole was administered, with no evidence of recurrence at 12 months following the operation. In this study, we demonstrate that T. serialis can cause CNS infection and that genetic analysis is recommended to establish a definitive diagnosis.

Real-world data are limited for patients with brain metastases secondary to metastatic breast cancer (MBC) and treated with cyclin-dependent kinase 4/6 inhibitors (CDK4/6i). This study describes real-world outcomes in patients with hormone receptor-positive, human epidermal growth factor 2-negative (HR⁺/HER2⁻) MBC with brain metastases diagnosis before abemaciclib initiation. A nationwide electronic health record-derived de-identified MBC database (January 2011-December 2021) was assessed retrospectively. Patients with HR⁺/HER2⁻ MBC who were treated with abemaciclib (monotherapy or in combination) following diagnosis of brain metastases were included. Real-world best response reflected clinician-documented response assessment of the brain imaging (intracranial) and change in disease burden following radiographic imaging (extracranial); these were reported descriptively. Time to treatment discontinuation (TTD), real-world progression-free survival (rwPFS), and overall survival (rwOS) were assessed using Kaplan-Meier methods from abemaciclib initiation (index date). Among 82 included patients (mean age 57.0 years; 98.8% female), 22.0% and 19.5% received CDK4/6i and chemotherapy before abemaciclib initiation, respectively, and the majority (80.5%) received radiation/local surgery to the brain before abemaciclib initiation. Patients mostly received abemaciclib as monotherapy (n = 6) or in combination with endocrine therapy (n = 68). Median TTD was 7.1 (95% CI 4.6-11.3) months, rwPFS was 9.2 (95% CI 6.0-11.6) months, and rwOS was 20.8 (95% CI 13.9-26.0) months. Intracranial and extracranial objective response rates, as determined by treating physicians, were 45.1% (n = 23/51) and 56.7% (n = 34/60), respectively. Intracranial and extracranial clinical benefit rates were 62.7% (n = 32/51) and 70.0% (n = 42/60), respectively. In this real-world study of patients diagnosed with brain metastases and initiating abemaciclib, most patients received radiation/local surgery to the brain before abemaciclib initiation. Although the outcomes in this real-world study are encouraging, it is unclear if the benefit was due to local therapy, abemaciclib, or the combination, and causality cannot be inferred. Further prospective clinical studies are needed to confirm the clinical benefit of this approach.

Background: Small bowel adenocarcinoma (SBA) accounts for <2% of all gastrointestinal malignancies. The most common organs of SBA metastases are the abdominal lymph node, liver, and peritoneum. There have been almost no reports of brain metastases of SBA. Dabaja et al. reported 1 case of brain metastasis out of 217 SBA cases, but details of the clinical course of the case were unclear. Our case might be the first report covering the full clinical course, pathological findings, and genetic data. Here, we report a very rare case of brain metastasis from poorly differentiated SBA. Case Description: A 54-year-old man who suffered from abdominal pain and melena visited a nearby hospital. This patient had no risk factors for SBA. He underwent partial resection of the jejunum with regional lymphadenectomy and combined resection of the transverse colon. Pathological diagnosis was poorly differentiated adenocarcinoma, pT4N2M0 Stage IIIB (UICC-TNM: 8^th edition). One month after curative surgery, liver metastasis was detected by a computed tomography (CT) scan, and then, palliative chemotherapy was started. During the third-line chemotherapy, a brain tumor on the left cerebellum was detected by the CT scan. Tumor resection was performed, and the histopathological features coincided with the primary jejunum tumor. Based on surgical, radiological, pathological, and genetic findings, this brain tumor was comprehensively diagnosed as a metastasis from poorly differentiated SBA. Conclusion: Here, we experienced a very rare case of brain metastasis from poorly differentiated SBA.