Abstract Ectopic hepatocellular carcinoma (EHCC) is an extremely rare neoplasm, especially in the mediastinum, which shares morphologic characteristics with intrahepatic hepatocellular carcinoma (HCC). Its clinical features remain unclear, posing significant diagnostic and therapeutic challenges. The prognosis is also unclear due to its rarity and potential variability. This study reports the first case of EHCC in the mediastinum with subsequent brain metastasis. A 50-year-old man presented with shoulder and chest discomfort persisting for 5 months, accompanied by progressive weight loss and fatigue over the preceding 2 years. Imaging showed a mediastinal mass initially suspected to be lymphoma due to its malignant characteristics. However, histopathological examination identified the lesion as HCC, supported by characteristic immunohistochemical markers, despite normal abdominal imaging. Two months later, the tumor progressed despite intensive radiotherapy, and the patient experienced recurrent seizures. Subsequent brain imaging confirmed multiple intracranial metastases. Unfortunately, the patient died 6 months after diagnosis. The ectopic liver is more susceptible to hepatocarcinogenesis than the main liver; this is attributed to its incomplete functional structure. EHCC can be considered as differential diagnosis of mediastinal masses, even when no intrahepatic HCC is found. The rarity of EHCC in the mediastinum poses difficulties in developing treatment protocols. This case emphasizes the diagnostic challenges and aggressive nature of ectopic HCC and the need for comprehensive management strategies. There are currently no definite guidelines regarding the diagnosis, treatment, and prognosis of EHCC.
ectopic hepatocellular carcinoma ; mediastinum ; metastasis

Humans ; Artificial Intelligence ; Lung Neoplasms/pathology* ; Mediastinum/pathology* ; Lymph Nodes/pathology* ; Neoplasm Staging ; Lymph Node Excision

This article reports a case of primary thyroid diffuse large B-cell lymphoma involving the superior mediastinum with Hashimoto's thyroiditis admitted to the Department of Otolaryngology and Head and Neck Surgery, First Hospital of Jilin University. This patient underwent right thyroid lobectomy and was transferred to the Department of Hematology of the Oncology Center for 6 courses of chemotherapy with R-CHOP protocol. The postoperative recovery was good, and the patient was regularly followed up for 12 months after the operation. The patient's condition was stable, and CT showed no abnormally high metabolism in the operation area indicating the inhibition of tumor activity, superficial lymph nodes and peripheral blood cells were normal. The case encountered many difficulties in the diagnosis process, and the diagnosis was not confirmed after puncture in two Grade III Class A hospitals in China. There are few patients with primary thyroid diffuse large B-cell lymphoma complicated with Hashimoto's thyroiditis, and it is particularly rare to invade the mediastinum. There is no report in China and abroad in the literature we reviewed. Therefore, this article reports the case and retrospectively analyzes the etiology, clinical symptoms, diagnosis and treatment of primary thyroid lymphoma.
Humans ; Mediastinum ; Retrospective Studies ; Hashimoto Disease ; Lymphoma, Large B-Cell, Diffuse ; Thyroid Neoplasms

Esophageal Perforation/etiology* ; Esophagus ; Foreign Bodies/complications* ; Humans ; Magnetic Phenomena ; Mediastinum

Child ; Humans ; Mediastinum ; Myoepithelioma/diagnosis*

Hematologic Diseases ; Hematopoiesis, Extramedullary ; Humans ; Mediastinal Neoplasms/surgery* ; Mediastinum ; Tomography, X-Ray Computed

OBJECTIVE: To validate the value of dual energy CT (DECT) in the differentiation of mediastinal metastatic lymph nodes from non-metastatic lymph nodes in non-small cell lung cancer (NSCLC). METHODS: In the study, 57 surgically confirmed NSCLC patients who underwent enhanced DECT scan within 2 weeks before operation were enrolled. Two radiologists analyzed the CT images before operation. All mediastinal lymph nodes with short diameter≥5 mm on axial images were included in this study. The morphological parameters [long-axis diameter (L), short-axis diameter (S) and S/L of lymph nodes] and the DECT parameters [iodine concentration (IC), normalized iodine concentration (NIC), slope of spectral hounsfield unit curve (λHU) and effective atomic number (Zeff) in arterial and venous phase] were measured. The differences of morphological parameters and DECT parameters between metastatic and non-metastatic lymph nodes were compared. The parameters with significant difference were analyzed by the Logistic regression model, then a new predictive variable was established. Receiver operator characteristic (ROC) analyses were performed for S, NIC in venous phase and the new predictive variable. RESULTS: In 57 patients, 49 metastatic lymph nodes and 938 non-metastatic lymph nodes were confirmed by surgical pathology. A total of 163 mediastinal lymph nodes (49 metastatic, 114 non-metastatic) with S≥5 mm were detected on axial CT images. The S, L and S/L of metastatic lymph nodes were significantly higher than those of non-metastatic lymph nodes (P < 0.05). The DECT parameters of metastatic lymph nodes were significantly lower than those of non-metastatic lymph nodes (P < 0.05). The best single morphological parameter for differentiation between metastatic and nonmetastatic lymph nodes was S (AUC, 0.752; threshold, 8.5 mm; sensitivity, 67.4%; specificity, 73.7%; accuracy, 71.8%). The best single DECT parameter for differentiation between metastatic and nonmetastatic lymph nodes was NIC in venous phase (AUC, 0.861; threshold, 0.53; sensitivity, 95.9%; specificity, 70.2%; accuracy, 77.9%). Multivariate analysis showed that S and NIC were independent predictors of lymph node metastasis. The AUC of combined S and NIC in the venous phase was 0.895(sensitivity, 79.6%; specificity, 87.7%; accuracy, 85.3%), which were significantly higher than that of S (P < 0.001) and NIC (P=0.037). CONCLUSIONS The ability of quantitative DECT parameters to distinguish mediastinal lymph node metastasis in NSCLC patients is better than that of morphological parameters. Combined S and NIC in venous phase can be used to improve preoperative diagnostic accuracy of metastatic lymph nodes.
Carcinoma, Non-Small-Cell Lung/diagnostic imaging* ; Humans ; Lung Neoplasms/diagnostic imaging* ; Lymph Nodes ; Lymphatic Metastasis ; Mediastinum ; Tomography, X-Ray Computed

OBJECTIVE: To 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 METHODS: We 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. RESULTS: The 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. CONCLUSION: Post-contrast CT attenuation, protrusion from the mediastinal pleura, and SUVmax were useful imaging features for distinguishing TETs from cysts in the anterior mediastinum.
Humans ; Logistic Models ; Mediastinum ; Multivariate Analysis ; Pleura ; Positron-Emission Tomography ; ROC Curve ; Thymus Neoplasms ; Tomography, X-Ray Computed

OBJECTIVE: To evaluate quantitative magnetic resonance imaging (MRI) parameters for differentiation of cysts from and solid masses in the anterior mediastinum. MATERIALS AND METHODS: The development dataset included 18 patients from two institutions with pathologically-proven cysts (n = 6) and solid masses (n = 12) in the anterior mediastinum. We measured the maximum diameter, normalized T1 and T2 signal intensity (nT1 and nT2), normalized apparent diffusion coefficient (nADC), and relative enhancement ratio (RER) of each lesion. RERs were obtained by non-rigid registration and subtraction of precontrast and postcontrast T1-weighted images. Differentiation criteria between cysts and solid masses were identified based on receiver operating characteristics analysis. For validation, two separate datasets were utilized: 15 patients with 8 cysts and 7 solid masses from another institution (validation dataset 1); and 11 patients with clinically diagnosed cysts stable for more than two years (validation dataset 2). Sensitivity and specificity were calculated from the validation datasets. RESULTS: nT2, nADC, and RER significantly differed between cysts and solid masses (p = 0.032, 0.013, and < 0.001, respectively). The following criteria differentiated cysts from solid masses: RER < 26.1%; nADC > 0.63; nT2 > 0.39. In validation dataset 1, the sensitivity of the RER, nADC, and nT2 criteria was 87.5%, 100%, and 75.0%, and the specificity was 100%, 40.0%, and 57.4%, respectively. In validation dataset 2, the sensitivity of the RER, nADC, and nT2 criteria was 90.9%, 90.9%, and 72.7%, respectively. CONCLUSION: Quantitative MRI criteria using nT2, nADC, and particularly RER can assist differentiation of cysts from solid masses in the anterior mediastinum.
Dataset ; Diffusion ; Humans ; Magnetic Resonance Imaging ; Mediastinal Cyst ; Mediastinum ; ROC Curve ; Sensitivity and Specificity ; Thymoma

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.
Giant Lymph Node Hyperplasia ; Hyperplasia ; Incidental Findings ; Lymphatic System ; Mediastinal Neoplasms ; Mediastinum ; Radiography ; Rare Diseases ; Thorax ; Trees