Background: Mediastinum is a small extra pleural anatomic compartment between the lungs where wide variety of lesions occurs. Division of mediastinum is helpful in developing a differential diagnosis. Aim: To analyse the pathological features of mediastinal lesions in our hospital. Materials and Methods: This is a retrospective hospital based study in tertiary care hospital on all primary mediastinal lesions over a period of six years (January 2012-December 2017). The data were retrieved from the archives of pathology department. Statistical analysis used: Microsoft Excel sheet. Results: Out of 80 mediastinal lesions, 62 were primary mediastinal lesions. Majority (58.1%) were in anterior compartment with male predominance and male to female ratio of 1.21:1. Age ranged from 11 days to 80 years and adult patients predominate. 44 cases (71%) were of neoplastic nature, among which thymus related tumours predominate followed by lymphoma, germ cell tumours and mesenchymal tumours. Non neoplastic lesions include mediastinal cysts, thymic remnants and thymic hyperplasia, reactive lymphadenitis, tuberculous lymphadenitis and extramedullary haematopoiesis. Conclusion: A multidisciplinary workup is needed in arriving at a diagnosis in case of mediastinal lesion for appropriate management of these rare lesions.

Keywords: Mediastinal lesions, thymic neoplasms, thymoma, mediastinal cysts