Heat Modulation of Intrinsic MR Contrasts for Tumor Characterization

(1) Background: The longitudinal relaxation time (T1), transverse relaxation time (T2), water proton chemical shift (CS), and apparent diffusion coefficient (ADC) are MR quantities that change with temperature. In this work, we investigate heat-induced intrinsic MR contrast types to add salient information to conventional MR imaging to improve tumor characterization. (2) Methods: Imaging tests were performed in vivo using different rat tumor models. The rats were cooled/heated to steady-state temperatures from 26–36 °C and quantitative measurements of T1, T2, and ADC were obtained. Temperature maps were measured using the proton resonance frequency shift (PRFS) method during the heating and cooling cycles. (3) Results: All tissue samples show repeatable relaxation parameter measurement over a range of 26–36 °C. Most notably, we observed a more than 3.3% change in T1/°C in breast adenocarcinoma tumors compared to a 1% change in benign breast fibroadenoma lesions. In addition, we note distinct values of T2/°C change for rat prostate carcinoma cells compared to benign tissue. (4) Conclusion: These findings suggest the possibility of improving MR imaging visualization and characterization of tissue with heat-induced contrast types. Specifically, these results suggest that the temporal thermal responses of heat-sensitive MR imaging contrast mechanisms in different tissue types contain information for improved (i) characterization of tumor/tissue boundaries for diagnostic and therapy purposes, and (ii) characterization of salient behavior of tissues, e.g., malignant versus benign tumors.

Accuracy of Mixed Reality Combined With Surgical Navigation Assisted Oral and Maxillofacial Tumor Resection

ObjectiveTo evaluate the feasibility and accuracy of mixed reality combined with surgical navigation in oral and maxillofacial tumor surgery.MethodsRetrospective analysis of data of seven patients with oral and maxillofacial tumors who underwent surgery between January 2019 and January 2021 using a combination of mixed reality and surgical navigation. Virtual surgical planning and navigation plan were based on preoperative CT datasets. Through IGT-Link port, mixed reality workstation was synchronized with surgical navigation, and surgical planning data were transferred to the mixed reality workstation. Osteotomy lines were marked with the aid of both surgical navigation and mixed reality images visualized through HoloLens. Frozen section examination was used to ensure negative surgical margins. Postoperative CT datasets were obtained 1 week after the surgery, and chromatographic analysis of virtual osteotomies and actual osteotomies was carried out. Patients received standard oncological postoperative follow-up.ResultsOf the seven patients, four had maxillary tumors and three had mandibular tumors. There were total of 13 osteotomy planes. Mean deviation between the planned osteotomy plane and the actual osteotomy plane was 1.68 ± 0.92 mm; the maximum deviation was 3.46 mm. Chromatographic analysis showed error of ≤3 mm for 80.16% of the points. Mean deviations of maxillary and mandibular osteotomy lines were approximate (1.60 ± 0.93 mm vs. 1.86 ± 0.93 mm). While five patients had benign tumors, two had malignant tumors. Mean deviations of osteotomy lines was comparable between patients with benign and malignant tumors (1.48 ± 0.74 mm vs. 2.18 ± 0.77 mm). Intraoperative frozen pathology confirmed negative resection margins in all cases. No tumor recurrence or complications occurred during mean follow-up of 15.7 months (range, 6-26 months).ConclusionThe combination of mixed reality technology and surgical navigation appears to be feasible, safe, and effective for tumor resection in the oral and maxillofacial region.

Resistance to Dopamine Agonists in Pituitary Tumors: Molecular Mechanisms

Pituitary neuroendocrine tumors (PitNET) are commonly benign tumors accounting for 10-25% of intracranial tumors. Prolactin-secreting adenomas represent the most predominant type of all PitNET and for this subtype of tumors, the medical therapy relies on the use of dopamine agonists (DAs). DAs yield an excellent therapeutic response in reducing tumor size and hormonal secretion targeting the dopamine receptor type 2 (D2DR) whose higher expression in prolactin-secreting adenomas compared to other PitNET is now well established. Moreover, although DAs therapy does not represent the first-line therapy for other PitNET, off-label use of DAs is considered in PitNET expressing D2DR. Nevertheless, DAs primary or secondary resistance, occurring in a subset of patients, may involve several molecular mechanisms, presently not fully elucidated. Dopamine receptors (DRs) expression is a prerequisite for a proper DA function in PitNET and several molecular events may negatively modify DR membrane expression, through the DRs down-regulation and intracellular trafficking, and DR signal transduction pathway. The current mini-review will summarise the presently known molecular events that underpin the unsuccessful therapy with DAs.

Benign Laryngeal Lesions

Benign laryngeal lesions represent a diverse set of pathologies whose clinical presentation may range from no symptoms to dyspnea and/or dysphonia. Flexible fiberoptic laryngoscopy and videolaryngostroboscopy are important in distinguishingdifferent types of lesions, and management and treatment are dependent on the identification of these lesions, as they have different etiologies. Some lesions such as vocal fold nodules and polyps are primarily phonotraumatic and may benefit fromspeech therapy and vocal hygiene as initial approaches. Vocal fold cysts and benign tumors may benefit from microlaryngeal approaches, while capillary ectasias, polypoid corditis, laryngoceles, saccular cysts, and papilloma may benefit from laser therapy. Vocal fold granulomas may arise from various etiologies such as intubation, traumatic behaviors, or reflux. Polypoid corditis arises from smoking. This review is intended to provide an overview of the variety of lesions that encompass non-malignant laryngeal lesions that is both suitable for junior and senior residents. This review contains 12 figures, 5 tables, and 64 references Keywords: Benign laryngeal lesions, Laryngocele, Polyp, Cyst, Polypoid Corditis, Papilloma

Intractable Trigeminal Neuralgia Secondary to Osteoma of the Clivus: A Case Report and Literature Review

Skull base osteomas (SBOs) are benign tumors that are frequently detected on radiographic images by coincidence. They are known for being slow-growing tumors and rarely symptomatic. The therapeutic approach for SBOs can differ substantially. Depending on the symptoms, size, and location of the tumor, this can range from serial observation to vigorous surgical extirpation. Clival osteoma is extremely rare. We report a case of clival osteoma, causing intractable trigeminal neuralgia due to the pressure effect on the trigeminal nerve at Meckel's cave. We also provide a review of pertinent literature. A 37-year-old woman presented with intractable trigeminal neuralgia. Cranial magnetic resonance imaging (MRI) demonstrated a large, lobulated, extra-axial lesion involving the right cerebellopontine angle and epicentering the clivus. Pathologically, the specimen was proven to be osteoma. The patient reported complete symptom resolution over a 4-year follow-up period. To the best of the authors' knowledge, this is the first clinical case of intractable trigeminal neuralgia due to clival osteoma.

Single Evaluation of Use of a Mixed Reality Headset for Intra-Procedural Image-Guidance during a Mock Laparoscopic Myomectomy on an Ex-Vivo Fibroid Model

Uterine fibroids represent the highest prevalence of benign tumors in women, with reports ranging from 4.5% to 68.6%, with a significant bias towards African American women. For uterine fibroids, a significant decision is determining whether fibroids can be successfully removed using minimally invasive (MI) techniques or their removal requires open surgery. Currently, the standard-of-care for intra-procedural visualization for myomectomies is ultrasound, which has low image quality and requires a specially trained assistant. Currently, the state-of-the-art is to obtain a pre-procedural MRI scan of the patient, which can be used for diagnosis and pre-procedural planning. Although proven incredibly useful pre-procedurally, MRI scans are not often used intra-procedurally due to the inconvenient visualization as 2D slices, which are seen on 2D monitors that do not intuitively convey the depth or orientation of the fibroids, as needed to effectively perform myomectomies. To address this limitation, herein, we present the use of a mixed reality headset (i.e., Microsoft HoloLens 2), as a tool for intra-procedural image-guidance during a mock myomectomy of an ex vivo animal uterus. In this work, we created a patient-specific holographic rendering by performing image segmentation of an MRI scan of a custom-made uterine fibroid animal model. A physician qualitatively assessed the usefulness of the renderings for fibroid localization, as compared to the same visualization on a 2D monitor. In conclusion, the use of mixed reality as an intra-procedural image guidance tool for myomectomies was perceived as a better visualization technique that could lead to improvements in MI approaches and make them accessible to patients from lower socioeconomic populations.

ABCC9 Is Downregulated and Prone to Microsatellite Instability on ABCC9tetra in Canine Breast Cancer

Tumorigenesis is associated with metabolic abnormalities and genomic instability. Microsatellite mutations, including microsatellite instability (MSI) and loss of heterozygosity (LOH), are associated with the functional impairment of some tumor-related genes. To investigate the role of MSI and LOH in sporadic breast tumors in canines, 22 tumors DNA samples and their adjacent normal tissues were evaluated using polyacrylamide gel electrophoresis and silver staining for 58 microsatellites. Quantitative real-time polymerase chain reaction, promoter methylation analysis and immunohistochemical staining were used to quantify gene expression. The results revealed that a total of 14 tumors (6 benign tumors and 8 breast cancers) exhibited instability as MSI-Low tumors. Most of the microsatellite loci possessed a single occurrence of mutations. The maximum number of MSI mutations on loci was observed in tumors with a lower degree of differentiation. Among the unstable markers, FH2060 (4/22), ABCC9tetra (4/22) and SCN11A (6/22) were high-frequency mutation sites, whereas FH2060 was a high-frequency LOH site (4/22). The ABCC9tetra locus was mutated only in cancerous tissue, although it was excluded by transcription. The corresponding genes and proteins were significantly downregulated in malignant tissues, particularly in tumors with MSI. Furthermore, the promoter methylation results of the adenosine triphosphate binding cassette subfamily C member 9 (ABCC9) showed that there was a high level of methylation in breast tissues, but only one case showed a significant elevation compared with the control. In conclusion, MSI-Low or MSI-Stable is characteristic of most sporadic mammary tumors. Genes associated with tumorigenesis are more likely to develop MSI. ABCC9 protein and transcription abnormalities may be associated with ABCC9tetra instability.

Transnasal endoscopic resection of nasal chondromesenchymal hamartoma in infancy: an analysis of 5 cases

Background Nasal chondromesenchymal hamartomas (NCMHs) are extremely rare benign tumors that most commonly affect children in the first year of life. The purpose of this study was to investigate and summarize the characteristics of NCMH cases and the efficacy of transnasal endoscopic resection of NCMHs. Methods This is a retrospective study including 5 cases of infant diagnosed as NCMH between April 2016 and April 2020. Diagnostic techniques include nasoendoscopy, computerized tomography (CT) scan, magnetic resonance imaging (MRI) with contrast and microscopic and immunohistologic studies. Data collected included patient demographics, patient symptoms, radiographic findings, characteristics of tumor growth, follow-up time, recurrence, and postoperative complications. Results In 5 cases, 3 were males and 2 were females who aged 1, 2, 3, 6 months and 1 year, respectively. The size of the mass measured 1.6 cm*1.9 cm*1.8 cm at its smallest and largest was 4.0 cm*3.5 cm*3.0 cm. All five patients underwent tumor resection via transnasal endoscopic approach. Four tumors were completely removed, and one underwent partial resection, which was completely resected by midfacial degloving operation 13 months after the first surgery. There was no postoperative complication. The current postoperative follow-up period was 1 to 4 years, and no recurrence has been observed. Conclusions Complete surgical resection of NCHM is necessary to resolve the symptoms and prevent recurrence. Transnasal endoscopic approach is a safe and effective choice for pediatric NCMH patients.

Sex Hormone Receptor Expression in Craniopharyngiomas and Association with Tumor Aggressiveness Characteristics

Craniopharyngiomas (CPs) are rare tumors of the sellar and suprasellar regions of embryonic origin. The primary treatment for CPs is surgery but it is often unsuccessful. Although CPs are considered benign tumors, they display a relatively high recurrence rate that might compromise quality of life. Previous studies have reported that CPs express sex hormone receptors, including estrogen and progesterone receptors. Here, we systematically analyzed estrogen receptor α (ERα) and progesterone receptor (PR) expression by immunohistochemistry in a well-characterized series of patients with CP (n = 41) and analyzed their potential association with tumor aggressiveness features. A substantial proportion of CPs displayed a marked expression of PR. However, most CPs expressed low levels of ERα. No major association between PR and ERα expression and clinical aggressiveness features was observed in CPs. Additionally, in our series, β-catenin accumulation was not related to tumor recurrence.