Electron Microscopic Investigation of Mediastinal Neoplasms: A Single-Center Experience

Various tumors occur in the mediastinum. Common mediastinal tumors include thymomas, lymphomas, germ cell tumors, neurogenic tumors, and less likely mesenchymal tumors. Transmission electron microscopy (TEM) is a useful modality for differentiating of histologically similar neoplasms. Here, we described our experience of twenty isolated mediastinal tumoral lesions using TEM.Materials and methodsIn this cross-sectional study, twenty cases of mediastinal tumors diagnosed by a radiologist and underwent resection by a thoracic surgeon sent to our referral electron microscope unit (affiliated to Shiraz University of Medical Sciences) included in the study. Clinical information included age, sex, signs, and symptoms of the patients were recorded for all cases. Compartment location of the lesions was extracted from radiological data. The tumors were investigated by TEM and all of the ultrastructural features were analyzed and photography was taken from appropriate findings. Immunohistochemical (IHC) analysis was also performed for confirmation of diagnosis. Continuous variables were presented as mean ± standard deviation. Categorical variables were expressed as frequencies and percentages and were analyzed using Chi-square analysis with SPSS version 21.0 software. Results Twenty cases of mediastinal mass consisted of 11(55%) male and 9(45%) female patients with age ranged from 8-70 years with a mean of 33.35±19.32. The major symptom was dyspnea followed by cough and chest pain. Final pathological diagnosis was respectively Hodgkin’s disease (30%), Non-Hodgkin’s Lymphoma (30%), thymoma (15%), malignant peripheral nerve sheath tumor (5%), thymic carcinoma (10%), metastatic ductal carcinoma of the breast (5%), and giant cell tumor (5%). Specific TEM features of each tumor were recorded and photography was taken. CT scan revealed the presence of masses in the anterior mediastinal space in almost all cases (except for malignant peripheral nerve sheath tumor). Most of the mediastinal lesions were primary in origin, except for two cases of metastatic carcinoma and a single case bone giant cell tumor with secondary mediastinal involvement. ConclusionThe mediastinum is a complex anatomic area and host to a wide range of neoplastic tumors. Among diagnostic tools, electron microscopy plays an important role. This study, by providing a basis for understanding the disease processes, could help for better diagnosis of known and unknown mediastinal tumors.

کلیدواژه ها:

Microscopy ، Electron ، Transmission ، Mediastinal Neoplasms ، Immunohistochemistry ، Iran