Mediastinal basaloid carcinoma arising from thymic cysts in two dogs.
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ABSTRACT:
SUBMITTER: Sano Y
PROVIDER: S-EPMC8182321 | biostudies-literature | 2021 Jun
REPOSITORIES: biostudies-literature
Publications
Mediastinal basaloid carcinoma arising from thymic cysts in two dogs.
Sano Yuto Y Seki Kanae K Miyoshi Kenjirou K Sakai Toshikazu T Kadosawa Tsuyoshi T Matsuda Kazuya K
The Journal of veterinary medical science 20210405 5
Mediastinal masses in dogs were diagnosed as basaloid carcinoma associated with multiple thymic cysts (MTCs). The masses were composed of MTCs and proliferating intracystic neoplastic basaloid cells, which immunohistochemically diffusely expressed p63 and cytokeratin 19. A gradual transition from the basal cell layers lining the cysts walls to the neoplastic cells was seen, and it was indicated that the neoplastic cells had originated from the basal cell layers of the cysts. To the best of our k ...[more]
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Project description:Background and objectiveMediastinal thymic cysts are a relatively rare pathology. With the expansion of eligible individuals screened with cross-sectional imaging for lung cancer, it is likely that there will be an increase in the number of individuals presenting with these cysts. Understanding this rare pathology will become more important when this incidental pathology is encountered.MethodsSearch of PubMed was undertaken using keywords "mediastinal", "mediastinum", "thymic", "thymus", "cyst". Relevant literature was reviewed and selected for this comprehensive narrative review, including case reports, case series, and retrospective reviews.Key content and findingsThymic cysts in the mediastinum can be classified into two broad categories, congenital and inflammatory. Accurate diagnosis by imaging is challenging and the majority of patients are asymptomatic. Literature suggests that the majority of cysts are benign, however an unknown percentage may harbor neoplastic processes and over time can cause significant compressive symptoms. Definitive treatment and diagnosis is surgical, with overall excellent outcomes. The decision to pursue surgical treatment versus surveillance requires a shared decision making approach with patients.ConclusionsGiven the scarcity of available high quality evidence regarding the management of mediastinal thymic cysts, this review provides practitioners a broad knowledge base to guide patients to make informed decisions.
| S-EPMC9792833 | biostudies-literature
Project description:Background Multilocular thymic cysts are sometimes associated with thymic epithelial tumors (TETs) and may be misdiagnosed as benign lesions. Cystic TETs generally progress during the course of follow-up. Case Description A 55-year-old woman was referred to our hospital in 2017. Her symptoms and physical exams were unremarkable. No abnormal lab results were detected other than elevated ESR (76 mm/lh). Contrast chest computed tomography (CT) showed an anterior mediastinal mass of 3×2×5 cm3 with heterogenous attenuation. The cystic feature was confirmed on contrast magnetic resonance imaging (MRI). Positron emission tomography (PET)-CT was also performed and there was no uptake in the lesion. Benign thymic cyst with infection was among the differential diagnoses. Therefore, intravenous antibiotics were administered for a week. A follow-up CT performed a month later showed a radical change: no visible lesion was present in the anterior mediastinum. Patient was cautioned that malignancy was still possible and that regular follow-up was necessary. The patient did not have another chest CT until the end of 2020. Follow-up chest CT showed lobulated anterior mediastinal mass with multiple pleural implants, highly suggestive of malignancy. Thymectomy plus pleurectomy was performed. Patient was discharged on post-operative day 10. Diagnosis: the pathology was thymic squamous cell carcinoma. The tumor invaded right pleura and pericardium, and pleural implants were confirmed metastasis (T2N0M1a, Stage IVa). Resection status was R0. Adjuvant radiation and chemotherapy were administered. Patient experienced recurrence after 10 months. Conclusions Multilocular thymic cysts can lead to misdiagnosis. Regular follow-up is needed if upfront surgery lacks evidence of malignancy and is deemed inappropriate at first. In cystic lesions or small lesions, it is sometimes difficult to make a clinical decision between surgery and follow-up based on imaging alone. Rash decision might result in unnecessary surgery or disease progression. Novel diagnostic tools might provide insights into the decision- making of these patients.
| S-EPMC9792815 | biostudies-literature
Project description:Background and objectiveWhether and when surgical intervention is indicated for mediastinal cysts is a matter of some debate. While most mediastinal cysts are found incidentally, the anatomic location, clinical presentation, and symptoms, as well as the potential for malignancy, are important considerations that inform decisions related to whether to intervene surgically. The objective of this review is to summarize the current literature regarding the criteria for surgical excision of mediastinal cysts and provide a framework for the clinician and surgeon to arrive at a decision regarding the appropriateness of surgical intervention of mediastinal cysts.MethodsA review of the published literature in the last 45 years (1977-2022) was conducted through PubMed, MeSh and Google Scholar. We included retrospective reviews, meta-analyses, and case studies published in the English language. A single author identified eligible studies, and those identified were reviewed by the team until consensus was met. Pediatric literature was excluded from this review.Key content and findingsThe current literature predominantly contains case studies, small retrospective studies, and meta-analyses describing mediastinal cysts. In the anterior mediastinum, multiloculated thymic cysts should be resected to rule out thymic malignancy. Intralesional fat, smooth borders, and a more midline location are features suggestive of a benign process, while asymmetric cystic wall thickening has been associated with malignancy. Both esophageal and bronchogenic cysts should be excised, taking into account the risk of complications (up to a 45% risk) of infection, rupture, or compression, as well as the rare risk of associated malignancy. Simple thymic and small pericardial cysts can be observed and followed with serial radiographic tools and should be resected if they increase in size, compress surrounding structures, or lead the patient to develop symptoms.ConclusionsSince mediastinal cysts are rare and often asymptomatic, there are no formal guidelines outlining when surgical intervention should be undertaken. Based on our review of the literature, surgical intervention should be pursued if the patient's symptoms correlate with radiographic findings of a mediastinal cyst, there is compression of the surrounding structures, and concern of malignancy is present.
| S-EPMC9792824 | biostudies-literature
Project description:The traditional approach to mediastinal cyst and mass resection has been open via median sternotomy or thoracotomy. With the advent of minimally invasive techniques, there have been successful cases completed via video-assisted thoracoscopic (VATS) and robot-assisted thoracoscopic surgery (RATS). Although mediastinal cysts are uncommon, they are a significant and relevant topic in the practice of thoracic surgery. Thus, this clinical practice review aims to summarize and highlight some of the key case series and retrospective studies in order to provide insight on each of the approaches. In addition, there is a brief review of other approaches, such as subxiphoid, and the utility of endobronchial ultrasound in the management of mediastinal cysts. In this review, the identified benefits of VATS and RATS lie largely in quality improvement of the patient experience-decreased length of stay (LOS) and pain-without compromising patient outcomes. However, the open approach remains a viable option, particularly for the management of large cysts or as a bail-out option. When surgeons approach with VATS or RATS and encounter bleeding or difficult dissection planes, it is consistent in the literature that conversion to thoracotomy is the safe next step. Our clinical practice is to attempt VATS or RATS approach for mediastinal cysts when possible. The data used for this review relies heavily on case reports and case series, and thus is the main limitation of this clinical practice review.
| S-EPMC9792838 | biostudies-literature
Project description:Following chemotherapy, a mediastinal germ cell tumor can lead to a mature teratoma that is composed of tissues derived from all three germ layers. Although teratoma is usually curable, in rare cases it can give rise to various somatic tumors and exceptionally it undergoes melanocytic neuroectodermal tumor (MNT) transformation, a process that is not well-described. We report a patient with a postchemotherapy thymic teratoma associated with an MNT component who, 10 years later, additionally presented a vertebral metastasis corresponding to an anaplastic MNT. Using exome sequencing of the mature teratoma, the MNT and its metastatic vertebral anaplastic MNT components, we identified 19 somatic mutations shared by at least two components. Six mutations were common to all three components, and three of them were located in the known cancer-related genes KRAS (p.E63K), TP53 (p.P222X), and POLQ (p.S447P). Gene set enrichment analysis revealed that the melanoma tumorigenesis pathway was enriched in mutated genes including the four major driver genes KRAS, TP53, ERBB4, and KDR, indicating that these genes may be involved in the development of the anaplastic MNT transformation of the teratoma. To our knowledge, this is the first molecular study realized on MNT. Understanding the clinicopathological and molecular characteristics of these tumors is essential to better understand their development and to improve therapeutics.
| S-EPMC10240838 | biostudies-literature
Project description:Despite the substantial role of chest MRI for the diagnosis and follow-up of thymic cysts, information about inter-reader agreement and optimal MR sequences is still limited. We aimed to investigate the inter-reader agreement for diagnosing thymic cysts using various combinations of MR sequences and to assess the effect of the addition of CT on inter-reader agreement. A total of 76 anterior mediastinal lesions (≤ 30 mm) from two tertiary referral hospitals (55 from Institution A and 21 from Institution B) who underwent chest CT and contrast-enhanced chest MR were included. Internal and external reading sets consisted of different combinations of MR sequences (pre- and post-contrast T1-weighted, T2-weighted, subtracted images, and diffusion-weighted imaging [DWI]/apparent diffusion coefficient [ADC] map) and CT. Four and three radiologists independently reviewed internal and external reading sets. The overall inter-reader agreement was moderate (κ = 0.50-0.57) for diagnosing cysts without significant differences between MR sequence combinations (all p-values > 0.05). The mean pairwise inter-reader agreement was the highest (κ = 0.65) when both the subtracted image and DWI/ADC map were provided. The addition of CT had no positive effect on the inter-reader agreement in the internal reading set (κ, from 0.57 to 0.50) but increased inter-reader agreement in the external reading set from moderate (κ = 0.48) to substantial (κ = 0.74). In conclusion, the overall inter-reader agreement for diagnosing thymic cysts on MRI was moderate. MR sequences including both the subtracted image and DWI/ADC map may be optimal in terms of inter-reader agreement.
| S-EPMC11794472 | biostudies-literature
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Project description:ObjectivesThis study aimed to distinguish preoperatively anterior mediastinal thymic cysts from thymic epithelial tumors via a computed tomography (CT)-based radiomics nomogram.MethodsThis study analyzed 74 samples of thymic cysts and 116 samples of thymic epithelial tumors as confirmed by pathology examination that were collected from January 2014 to December 2020. Among the patients, 151 cases (scanned at CT 1) were selected as the training cohort, and 39 cases (scanned at CT 2 and 3) served as the validation cohort. Radiomics features were extracted from pre-contrast CT images. Key features were selected by SelectKBest and least absolute shrinkage and selection operator and then used to build a radiomics signature (Rad-score). The radiomics nomogram developed herein via multivariate logistic regression analysis incorporated clinical factors, conventional CT findings, and Rad-score. Its performance in distinguishing the samples of thymic cysts from those of thymic epithelial tumors was assessed via discrimination, calibration curve, and decision curve analysis (DCA).ResultsThe radiomics nomogram, which incorporated 16 radiomics features and 3 conventional CT findings, including lesion edge, lobulation, and CT value, performed better than Rad-score, conventional CT model, and the clinical judgment by radiologists in distinguishing thymic cysts from thymic epithelial tumors. The area under the receiver operating characteristic (ROC) curve of the nomogram was 0.980 [95% confidence interval (CI), 0.963-0.993] in the training cohort and 0.992 (95% CI, 0.969-1.000) in the validation cohort. The calibration curve and the results of DCA indicated that the nomogram has good consistency and valuable clinical utility.ConclusionThe CT-based radiomics nomogram presented herein may serve as an effective and convenient tool for differentiating thymic cysts from thymic epithelial tumors. Thus, it may aid in clinical decision-making.
| S-EPMC8702557 | biostudies-literature
Project description:ObjectiveTo investigate whether computed tomography (CT) and fluorine-18-labeled fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) may be applied to distinguish thymic epithelial tumors (TETs) from benign cysts in the anterior mediastinum.Materials and methodsWe included 262 consecutive patients with pathologically proven TETs and benign cysts 5 cm or smaller who underwent preoperative CT scans. In addition to conventional morphological and ancillary CT findings, the relationship between the lesion and the adjacent mediastinal pleura was evaluated qualitatively and quantitatively. Mean lesion attenuation was measured on CT images. The maximum standardized uptake value (SUVmax) was obtained with FDG-PET scans in 40 patients. CT predictors for TETs were identified with multivariate logistic regression analysis. For validation, we assessed the diagnostic accuracy and inter-observer agreement between four radiologists in a size-matched set of 24 cysts and 24 TETs using a receiver operating characteristic curve before and after being informed of the study findings.ResultsThe multivariate analysis showed that post-contrast attenuation of 60 Hounsfield unit or higher (odds ratio [OR], 12.734; 95% confidence interval [CI], 2.506-64.705; p = 0.002) and the presence of protrusion from the mediastinal pleura (OR, 9.855; 95% CI, 1.749-55.535; p = 0.009) were the strongest CT predictors for TETs. SUVmax was significantly higher in TETs than in cysts (5.3 ± 2.4 vs. 1.1 ± 0.3; p < 0.001). After being informed of the study findings, the readers' area under the curve improved from 0.872-0.955 to 0.949-0.999 (p = 0.066-0.149). Inter-observer kappa values for protrusion were 0.630-0.941.ConclusionPost-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.
| S-EPMC6424822 | biostudies-literature
Project description:BackgroundNeuroendocrine (NE) differentiation is widely studied in non-small cell lung carcinomas (NSCLC) however, its significance remains unclear in basaloid squamous cell carcinomas (B-SqCC). This study aims to assess the extent of NE differentiation in B-SqCC and characterize the underlying molecular process.MethodsThis study evaluated resected B-SqCC, small cell lung cancer (SCLC) and poorly differentiated SqCC (PD-SqCC) from 2005 to 2020 at the Ottawa Hospital. Samples were subject to pathological review, immunohistochemistry (IHC) and survival analysis. Gene expression analysis was performed on B-SqCC samples exhibiting NE+ and NE- regions (paired samples) to identify differentially expressed genes (DEGs). These DEGs were subsequently validated in unpaired B-SqCC and TCGA samples.ResultsB-SqCC cases were more likely to exhibit nuclear molding, resetting and peripheral palisading than PD-SqCC. B-SqCC were also more likely to demonstrate NE differentiation compared to PD-SqCC (p = 0.006). Pure basaloid squamous cell carcinoma (PB-SqCC) experienced poorer disease-free survival (HR = 3.12, p = 0.043) adjusted for stage. Molecular characterization of paired B-SqCC samples demonstrated DEGs implicated in NOTCH signaling, SCLC and pulmonary neuroendocrine differentiation. Hierarchical clustering using discovered DEGs in unpaired B-SqCC samples distinguished tumors based on NE status (p = 0.048). Likewise, clustering The Cancer Genome Atlas (TCGA) samples with DEGs distinguished B-SqCC from SqCC samples (p = 0.0094).ConclusionThis study provides IHC and molecular evidence of significant NE-differentiation in B-SqCC and demonstrates their aggressive clinical behavior. These findings suggest that B-SqCC are biologically distinct from SqCC and share characteristics with SCLC.
| S-EPMC9088121 | biostudies-literature