BACKGROUND: This study was an epidemiological analysis of all primary mediastinal neoplasms (PMNs) diagnosed between 2000 and 2016 at the National Tuberculosis and Lung Diseases Research Institute, Poland. METHODS: All patients with any mediastinal abnormality were included in the analysis. The patients' age and gender were obtained from the institutional database. RESULTS: From a cohort of 5,108 patients, 3,691 primary mediastinal lesions were found, including 1,005 (19%) PMNs: lymphomas (533, 53% of PMNs), thymomas (215, 21%), neurogenic tumors (NTs) (100, 10%), germ cell tumors (GCTs) (62, 6%), soft tissue tumors (STTs) (47, 5%) and thymic carcinomas/thymic neuroendocrine tumors (TCs/TNETs) (37 in total, 4%). The most frequent lymphomas were classical Hodgkin lymphomas [256] and primary mediastinal large B-cell lymphomas [163]. Type AB [73] predominated in thymomas and squamous cell carcinomas [9] and carcinoids [10] in TCs/TNETs. NTs encompassed mainly schwannomas [49], ganglioneuromas [21] and neurofibromas [10]. The most frequent STTs were hemangiomas [13] and lymphangiomas [11]. Lymphomas, thymomas and NT were more often in women, TCs/TNETs in men (P<0.001). Lymphomas predominated between the 2nd and 4th decade of life, NTs under the 3rd decade and thymic epithelial tumors between the 6th and 8th decade (P<0.001). There was no correlation between the subtypes of thymomas and the patients' gender (P=0.389) but it was found between histology and patients' age: in patients <30 years of age type B2 and B3 thymomas and >70 years of age AB type and micronodular thymomas with lymphoid stroma (P<0.001) predominated. In the group of GCTs half of them were malignant and these were noted exclusively in men. No correlation between subtypes of NTs or TCs/TNETs and patients' age and gender was found (P>0.05). CONCLUSIONS: PMNs are rare conditions thus awareness of basic epidemiology may be very helpful for final diagnosis.
BACKGROUND: This study was an epidemiological analysis of all primary mediastinal neoplasms (PMNs) diagnosed between 2000 and 2016 at the National Tuberculosis and Lung Diseases Research Institute, Poland. METHODS: All patients with any mediastinal abnormality were included in the analysis. The patients' age and gender were obtained from the institutional database. RESULTS: From a cohort of 5,108 patients, 3,691 primary mediastinal lesions were found, including 1,005 (19%) PMNs: lymphomas (533, 53% of PMNs), thymomas (215, 21%), neurogenic tumors (NTs) (100, 10%), germ cell tumors (GCTs) (62, 6%), soft tissue tumors (STTs) (47, 5%) and thymic carcinomas/thymic neuroendocrine tumors (TCs/TNETs) (37 in total, 4%). The most frequent lymphomas were classical Hodgkin lymphomas [256] and primary mediastinal large B-cell lymphomas [163]. Type AB [73] predominated in thymomas and squamous cell carcinomas [9] and carcinoids [10] in TCs/TNETs. NTs encompassed mainly schwannomas [49], ganglioneuromas [21] and neurofibromas [10]. The most frequent STTs were hemangiomas [13] and lymphangiomas [11]. Lymphomas, thymomas and NT were more often in women, TCs/TNETs in men (P<0.001). Lymphomas predominated between the 2nd and 4th decade of life, NTs under the 3rd decade and thymic epithelial tumors between the 6th and 8th decade (P<0.001). There was no correlation between the subtypes of thymomas and the patients' gender (P=0.389) but it was found between histology and patients' age: in patients <30 years of age type B2 and B3 thymomas and >70 years of age AB type and micronodular thymomas with lymphoid stroma (P<0.001) predominated. In the group of GCTs half of them were malignant and these were noted exclusively in men. No correlation between subtypes of NTs or TCs/TNETs and patients' age and gender was found (P>0.05). CONCLUSIONS: PMNs are rare conditions thus awareness of basic epidemiology may be very helpful for final diagnosis.