Advanced biomedical imaging for accurate discrimination and prognostication of mediastinal masses.

BACKGROUND: To investigate the potential of radiomic features and dual-source dual-energy CT (DECT) parameters in differentiating between benign and malignant mediastinal masses and predicting patient outcomes. METHODS: In this retrospective study, we analysed data from 90 patients (38 females, mean age 51 ± 25 years) with confirmed mediastinal masses who underwent contrast-enhanced DECT. Attenuation, radiomic features and DECT-derived imaging parameters were evaluated by two experienced readers. We performed analysis of variance (ANOVA) and Chi-square statistic tests for data comparison. Receiver operating characteristic curve analysis and Cox regression tests were used to differentiate between mediastinal masses. RESULTS: Of the 90 mediastinal masses, 49 (54%) were benign, including cases of thymic hyperplasia/thymic rebound (n = 10), mediastinitis (n = 16) and thymoma (n = 23). The remaining 41 (46%) lesions were classified as malignant, consisting of lymphoma (n = 28), mediastinal tumour (n = 4) and thymic carcinoma (n = 9). Significant differences were observed between benign and malignant mediastinal masses in all DECT-derived parameters (p ≤ .001) and 38 radiomic features (p ≤ .044) obtained from contrast-enhanced DECT. The combination of these methods achieved an area under the curve of .98 (95% CI, .893-1.000; p < .001) to differentiate between benign and malignant masses, with 100% sensitivity and 91% specificity. Throughout a follow-up of 1800 days, a multiparametric model incorporating radiomic features, DECT parameters and gender showed promising prognostic power in predicting all-cause mortality (c-index = .8 [95% CI, .702-.890], p < .001). CONCLUSIONS: A multiparametric approach combining radiomic features and DECT-derived imaging biomarkers allows for accurate and noninvasive differentiation between benign and malignant masses in the anterior mediastinum.

Multiparametric Evaluation of Radiomics Features and Dual-Energy CT Iodine Maps for Discrimination and Outcome Prediction of Thymic Masses.

RATIONALE AND OBJECTIVES: To investigate the diagnostic value of radiomics features and dual-source dual-energy CT (DECT) based material decomposition in differentiating low-risk thymomas, high-risk thymomas, and thymic carcinomas. MATERIALS AND METHODS: This retrospective study included 32 patients (16 males, mean age 66 ± 14 years) with pathologically confirmed thymic masses who underwent contrast-enhanced DECT between 10/2014 and 01/2023. Two experienced readers evaluated all patients regarding conventional radiomics features, as well as DECT-based features, including attenuation (HU), iodine density (mg/mL), and fat fraction (%). Data comparisons were performed using analysis of variance and chi-square statistic tests. Receiver operating characteristic curve analysis and Cox-regression tests were used to discriminate between low-risk/high-risk thymomas and thymic carcinomas. RESULTS: Of the 32 thymic tumors, 12 (38%) were low-risk thymomas, 11 (34%) were high-risk thymomas, and 9 (28%) were thymic carcinomas. Values differed significantly between low-risk thymoma, high-risk thymoma, and thymic carcinoma regarding DECT-based features (p ≤ 0.023) and 30 radiomics features (p ≤ 0.037). The area under the curve to differentiate between low-risk/high-risk thymomas and thymic cancer was 0.998 (95% CI, 0.915-1.000; p < 0.001) for the combination of DECT imaging parameters and radiomics features, yielding a sensitivity of 100% and specificity of 96%. During a follow-up of 60 months (IQR, 35-60 months), the multiparametric approach including radiomics features, DECT parameters, and clinical parameters showed an excellent prognostic power to predict all-cause mortality (c-index = 0.978 [95% CI, 0.958-0.998], p = 0.003). CONCLUSION: A multiparametric approach including conventional radiomics features and DECT-based features facilitates accurate, non-invasive discrimination between low-risk/high-risk thymomas and thymic carcinomas.

Open surgical treatment of superior vena cava syndrome due to invasive thymoma.

Here we describe a case of open surgery for superior vena cava syndrome due to invasive thymoma. An 85-year-old woman presented with facial swelling and exertional dyspnea. Computed axial tomography revealed a thymoma in the mediastinum, extending to the superior vena cava, right atrium, and bilateral brachiocephalic veins. Endovascular therapy did not seem feasible because superior vena cava appeared totally occluded, and stenting could cause tumor embolism to the pulmonary arteries. Open surgery facilitated macroscopically complete and successful tumor resection. If long-term survival seems possible, open surgery could be a viable treatment option for superior vena cava syndrome that is ineligible for endovascular therapy.

Efficacy of contrast-enhanced ultrasound-guided percutaneous core needle biopsy in anterior mediastinal masses.

Objective: To evaluate the efficacy and safety of percutaneous core needle biopsy (PCNB) using ultrasound (US)-guided and contrast-enhanced ultrasound (CEUS)-guided procedures for anterior mediastinal masses (AMMs). Methods: In total, 284 consecutive patients (166 men, 118 women; mean age, 43.0 â€‹± â€‹18.4 years) who underwent PCNB for AMMs were enrolled. Patients were divided into the US-guided group (n â€‹= â€‹133) and the CEUS-guided group (n â€‹= â€‹151). PCNB was performed using a core needle (16-gauge or 18-gauge). Internal necrosis, diagnostic yield, and diagnostic accuracy were compared between the two groups. Results: The predominant final diagnosis of the cases in this study was thymoma (29.7%), lymphoma (20.5%), thymic carcinoma (13.3%), and germ cell tumour (13.3%), respectively. There was no significant difference in patient age, sex, number of percutaneous biopsies, or display rate of internal necrosis on conventional US between the two groups. The rate of internal necrosis of the lesions was significantly higher after contrast agent injection (72.2% vs. 41.7%; P â€‹< â€‹0.001). The CEUS-guided group had a higher diagnostic yield than the US-guided group (100% vs. 89.5%, P â€‹< â€‹0.001). There was no significant difference between the diagnostic accuracy of the CEUS-guided and US-guided groups (97.3% vs. 97.4%; P â€‹= â€‹1.000). None of the patients experienced adverse reactions or complications after US-guided or CEUS-guided PCNB. Conclusions: CEUS-guided PCNB can improve the diagnostic yield by optimizing the biopsy procedure.

Outcomes of dogs with thymoma treated with intensity modulated stereotactic body radiation therapy or non-modulated hypofractionated radiation therapy.

Canine thymomas are routinely treated with radiotherapy (RT). In this study, we investigate the response and toxicity of canine thymoma treated with intensity-modulated stereotactic body radiation therapy (SBRT) relative to dogs treated with hypofractionated non-modulated radiation therapy (NMRT). A retrospective study was performed of dogs with thymoma treated with RT (total: n = 15; SBRT: n = 8, NMRT: n = 7). Tumour response was evaluated in six dogs (40%); following SBRT, three dogs (100%) experienced stable disease (SD); following NMRT, one dog (33%) had a PR, and two dogs (67%) had SD. Median PFS was 116 days (range 66-727 days) for the SBRT group and 134 days (range 10-405 days) for the NMRT group. The MST for the SBRT group was 250 days (range 1-727 days) and 155 days (range 10-405 days) for NMRT. Median disease-specific survival was 250 days (range 1-727 days) for the SBRT group and 169 days (range 20-405 days) for the NMRT group. No significant differences in survival data were found between the treatment groups, however the results from the small number of dogs analysed are likely underpowered for statistical comparisons. Reported acute and late side effects were limited to the lungs and heart and were statistically significantly more common in the NMRT (71%) compared to the SBRT group (25%) (p = .04). We suggest similar treatment efficacy may be provided for canine thymoma treated with either approach, but SBRT could provide the clinical benefit of reduced incidence of radiation-induced toxicity and completion of RT in a shorter time frame.

Delayed solitary mediastinal lymph node metastasis from a benign meningothelial meningioma six years after surgical resection of an intracranial tumor.

Meningiomas are common intracranial neoplasms with benign features, and extracranial metastases are very rare. There have been no previous reports of solitary mediastinal lymph node metastasis from benign meningiomas without pulmonary lesions. Here, we present a case of an 82-year-old female who visited our department for mediastinal lymphadenopathy with a history of meningioma treated with total surgical resection six years prior. Endobronchial ultrasound-guided transbronchial needle aspiration of the left lower paratracheal lymph node revealed a benign meningothelial meningioma. In patients with a history of meningioma, extracranial metastasis should be considered in the differential diagnosis of mediastinal lymphadenopathy.

Rare case of cavernous hemangioma of the thymus.

Cavernous hemangioma (CH) of the thymus is an extremely rare congenital venous malformation. Related symptoms are non-specific and patients are often asymptomatic. The diagnosis is difficult to make either by non-invasive or mini-invasive procedures. Surgical resection is usually required for diagnosis and treatment. We report a case of a 46-year-old men with an incidental finding of an anterior mediastinal tissue mass on chest computed tomography scan. A complete surgical resection of the mass was performed. Histopathological examination concluded to a thymic CH.

Diagnostic outcome and safety of CT-guided core needle biopsy for mediastinal masses: a systematic review and meta-analysis.

OBJECTIVES: This systematic review and meta-analysis aimed to evaluate the diagnostic outcomes and complication rates and to identify potential covariates that could influence these results for computed tomography (CT)-guided core needle biopsy (CNB) of mediastinal masses. METHODS: A computerized search of the PubMed and EMBASE databases was performed to identify original articles on the use of CT-guided CNB for mediastinal mass. The pooled proportions of the diagnostic yield and accuracy were assessed using random effects modeling. We assessed the pooled proportion of complication rates using random effects or fixed effects modeling. Multivariate meta-regression analyses were performed to evaluate the potential sources of heterogeneity. RESULTS: Eighteen eligible studies (1310 patients with 1345 CT-guided CNBs) were included. The pooled proportions of the diagnostic yield and accuracy of CT-guided CNB for mediastinal masses were 92% (18 studies, 1345 procedures) and 94% (15 studies, 803 procedures), respectively. In the subgroup analysis, the pooled proportions of the total complication rate and major complication rate were 13% and 2%, respectively. In the meta-regression analyses, the number of tissue samplings (odds ratio [OR], 3.3; p = 0.03), real-time fluoroscopy-guided (OR, 2.1; p = 0.02), and percentage of lymphoma (OR, 2.2; p < 0.001) for diagnostic yield, number of tissue samplings (OR = 2.0, p = 0.02) for diagnostic accuracy, and biopsy needle diameter (OR, 2.5; p = 0.002) for total complication rate were all sources of heterogeneity. CONCLUSIONS: CT-guided CNB for mediastinal mass demonstrates high diagnostic outcomes and low complication rates. The use of 20-gauge biopsy needles and obtaining ≥ 3 samples may be recommended to improve diagnostic outcomes and decrease complication rates. KEY POINTS: • The pooled estimates of diagnostic yield and accuracy of computed tomography (CT)-guided core needle biopsy (CNB) for mediastinal masses are 92% and 94%, respectively. • The pooled estimates of the total complication rate and major complication rate were 13% and 2%, respectively. • The use of a 20-gauge needle and ≥ 3 tissue samplings are recommended for CT-guided mediastinal CNB to achieve high diagnostic outcomes and lower complication rates.

Update in diagnostic imaging of the thymus and anterior mediastinal masses.

Anterior mediastinal masses include a wide spectrum of malignant and benign pathologies with a large percentage represented by thymic lesions. Distinguishing these masses on diagnostic imaging is fundamental to guide the proper management for each patient. This review illustrates possibilities and limits of different imaging modalities to diagnose a lesion of the anterior mediastinum with particular attention to thymic disease.

Development of Castleman Disease in the Paravertebral Space Mimicking a Neurogenic Tumor.

Castleman disease is a relatively rare disease, characterized by well-circumscribed benign lymph-node hyperplasia. The disease may develop anywhere in the lymphatic system, but is most commonly reported as unicentric Castleman disease in the mediastinum along the tracheobronchial tree. It is usually asymptomatic and detected on plain chest radiography as an incidental finding. We report an incidentally detected case of Castleman disease in the paravertebral space that was preoperatively diagnosed as a neurogenic tumor and treated by complete surgical resection.

Development of Castleman Disease in the Paravertebral Space Mimicking a Neurogenic Tumor / 대한흉부외과학회지

Castleman disease is a relatively rare disease, characterized by well-circumscribed benign lymph-node hyperplasia. The disease may develop anywhere in the lymphatic system, but is most commonly reported as unicentric Castleman disease in the mediastinum along the tracheobronchial tree. It is usually asymptomatic and detected on plain chest radiography as an incidental finding. We report an incidentally detected case of Castleman disease in the paravertebral space that was preoperatively diagnosed as a neurogenic tumor and treated by complete surgical resection.

[Lymphatic malformation of cervical-supraclavicular area with large mediastinal component]. / Limfaticheskaia mal'formatsiia sheino-nadkliuchichnoi oblasti s mediastinal'nym komponentom bol'shikh razmerov.

Lymphatic malformation (LM) is a benign neoplasm that consists of abnormally formed lymphatic vessels and cavities. The incidence of LM is 6% among all benign tumors. Mediastinal localization is extremely rare, only case reports in adults are described. Clinical observation of 42-year-old patient with LM of cervical-supraclavicular area and large mediastinal component communicating with thoracic lymphatic duct is presented. The first stage was thoracoscopic clipping of thoracic lymphatic duct, the second one - radical surgery through combined cervico-sterno-thoracotomy.

Thoracic Neoplasms in Children: Contemporary Perspectives and Imaging Assessment.

This article focuses on commonly encountered primary lung, airway, mediastinal, and chest wall neoplasms that occur in the pediatric population. Although primary pediatric thoracic neoplasms are rare, imaging is critical in their diagnostic work-up. An overview of the latest imaging techniques specific to evaluate these pediatric thoracic neoplasms is presented across the spectrum of modalities from radiography to PET/MR imaging. In addition, the characteristic imaging appearances of these pediatric primary thoracic neoplasms are discussed with an emphasis on what the radiologist needs to know in routine clinical practice.

Diffusion-weighted MR imaging vs. multi-detector row CT: Direct comparison of capability for assessment of management needs for anterior mediastinal solitary tumors.

PURPOSE: To evaluate and compare the capability of diffusion-weighted MR imaging (DWI) and CT for assessment of management needs for anterior mediastinal solitary tumors. MATERIALS AND METHODS: Thirty-five patients with pathologically confirmed anterior mediastinal tumors were enrolled. The tumors were divided into two groups according to need for management: tumors not needing further intervention or treatment (group A; thymoma type A, AB and B1) and tumors needing further intervention and treatment (group B; other thymoma types and malignancies). The apparent diffusion coefficient (ADC) of each tumor was measured, and probabilities of malignancy and need for further intervention and treatment were visually assessed on CT. The differences in ADCs between group A and B and between malignancies and thymomas in group B were evaluated with the Mann-Whitney's U-test. Feasible threshold values for differentiation of group B from group A and distinguishing malignancies from thymomas assessed as group B were determined by the ROC-based positive test, and McNemar's test was used for comparing diagnostic capabilities of DWI with those of CT. RESULTS: ADCs for the two groups were significantly different (p<0.001). Application of the threshold value for differentiation of group B from A showed no significant difference (p>0.05). Application of the feasible threshold value for distinguishing malignant from thymomas assessed as group B showed that specificity (76.9%) and accuracy (85.2%) of DWI were significantly better than those of visual score (p<0.05). CONCLUSION: DWI has useful potential for the assessment of management needs for anterior mediastinum solitary tumors as well as CT.

Anterior mediastinal synovial sarcoma: A case report and literature review / 解放军医学杂志

Objective To study the clinical manifestations, pathologic features, diagnosis, treatment and prognosis of primary synovial sarcoma in the anterior mediastinum. Methods A case of primary synovial sarcoma in the anterior mediastinum was reported. Clinical features, imaging manifestations, pathology features and therapeutic effect were analysed and the relevant literature was reviewed. Results A 48-year-male patient was admitted with complaint of right chest pain for 4 days. Chest computerized tomography revealed a large mass located at the right anterior mediastinum, and it was primarily diagnosed as invasive thymoma. Pathological examination by CT-guided percutaneous needle biopsy manifested that, under microscope, the tumor cells were short and spindle in shape forming a nest structure, suggested it was a thymoma. The patient then underwent resection of thymoma with removal of fat and connective tissue in the anterior mediastinum. During the operation the size of the tumor was 15cm × 15cm × 10cm, being located at the anterior mediastinum, and it tended to bleed. The diagnosis of primary monophasic synovial sarcoma in the mediastinum was confirmed by postoperative/pathology examination. Immunohistochemistry staining showed that the tumor cells were positive for the markers Bcl-2 and EMA, but negative for the markers CK (pan) and S100. The patient suffered from local recurrence with metastases to lung 4 months after surgery. The patient received 2 chemotherapeutic courses with ifosfamide, epirubicin and cisplatin. He died 6 months after surgery. Conclusion Primary synovial sarcoma in the anterior mediastinum is an extremely rare and highly malignant tumor with poor prognosis. The diagnosis depends on the pathological features, immunohistochemistry and RT-PCR. Radical resection combined with comprehensive treatment may improve the survival rate.

Carcinoma tímico metastático com resposta prolongada a pemetrexed e octreotide / Metastatic thymic carcinoma with prolonged response to pemetrexed and octreotide

Em adultos os carcinomas tímicos representam cerca de 20% das neoplasias mediastinais. A maioria dos pacientes tem entre 40 e 60 anos de idade e há ligeira predominância do sexo masculino. Em função da raridade da doença não há ensaios clínicos randomizados realizados para orientar a escolha do tratamento na doença metastática refratária ou recorrente. Alguns regimes de segunda linha têm sido usados, a maioria baseada em cisplatina. Como linhas alternativas as opções são pemetrexed, 5-flourouracil associado a leucovorin, gemcitabina, capecitabina e paclitaxel, todas com taxas de resposta pequenas. Relatamos neste artigo um caso de carcinoma tímico tratado com pemetrexed e octreotide com resposta prolongada ao tratamento.

Inflammatory pseudotumor in the mediastinum: imaging with (18)F-fluorodeoxyglucose PET/CT.

Mediastinal inflammatory pseudotumor is a rare benign disease with its capability for local invasion and rapid growth. We present a case of middle-mediastinal inflammatory pseudotumor and report its contrast-enhanced chest computed tomography, (18)F-fluorodeoxyglucose positron emission tomography/computed tomography and pathologic findings.