Pathological analysis of mediastinal masses in National Hospital for respiratory diseases, Sri Lanka

This study describes pathological findings of mediastinal masses among patients referred to National Hospital for Respiratory Diseases. Methods A descriptive cross-sectional study was conducted among patients with mediastinal masses referred to National Hospital for Respiratory Diseases, Welisara, Sri Lanka in 2017, who underwent excision or guided biopsy followed by standard histological and immunohistochemical staining. Results The population was aged 8-75[mean (SD) =42.8(17.0)] years. Of 139 patients, 80(57.6%) were males. Masses were located in anterior mediastinum in 49.6 %( n=69), superior mediastinum in 20.1 %( n=28), middle mediastinum in 15.1%( n=21) and posterior mediastinum in 14.4 %( n=20). Majority (65.5%, n=91) were excision biopsies. The rest were core biopsies. Commonest mass was lymphoma [n=27,19.4%;Non-Hodgkin(n=20),Hodgkin(n=7)] followed by thymic tumours [n=22,15.8%;benign(n=16), malignant(n=6)], germ cell tumours (11.5%,n=16), metastatic deposits (10.8%,n=15), developmental cysts (8.6%,n=12), non-neoplastic lymphadenitis (7.9%,n=11), neuroectodermal tumours (5.8%,n=8), soft tissue sarcomas (2.9%,n=4), leiomyoma (0.7%,n=1), benign spindle cell tumour (0.7%,n=1) and plasmacytoma (0.7%,n=1). Twentyone (15.1%) specimens were either normal or inconclusive. A one-way ANOVA showed significant differences in the distribution of age among different types of masses [Welch's F (df=7, n=115) =10.09, p=.000]. Post-hoc comparisons, showed that the age of patients with germ cell tumours ( m e a n = 2 9 . 7 ± 11 . 5 y e a r s ) , developmental cysts (mean=38.8±16.5years) and lymphomas (mean=34.0±15.7 years) were less compared to the patients with other masses. A Chi-square test indicated no significant association between gender and the type of mediastinal mass [χ2 (df=7, n=115) =6.561, p=.48]. Conclusions Lymphoma was the commonest mediastinal mass in this population. Germ cell tumours, developmental cysts and lymphomas were commonly found among the young.