Clinicopathological Analysis of Mediastinal Masses: A Mixed Bag of Non-Neoplastic and Neoplastic Etiologies

Abstract

Objective: The mediastinum is the central portion of the thoracic cavity, housing numerous organs and harbouring a mixed bag of non-neoplastic and neoplastic lesions. Accurate diagnosis is essential owing to the widely variable therapeutic and prognostic implications. Material and Method: Cases of mediastinal masses were retrospectively reviewed from January 2011 till January 2016. Clinico-radiological records of these cases were retrieved. Fine needle aspiration cytology (FNAC) was performed wherever feasible. Histopathological and immunohistochemical evaluation of the excised specimens was undertaken. Results: Of the 60 cases included in our study, 22 were anterior, 20 were middle and 18 posterior mediastinal masses. The majority of the patients were symptomatic (96.8%). The most common pathology was thymoma (12 cases) followed by ten cases of lymphoma, eight cases each of tubercular lymphadenopathy and schwannoma, six cases of neurofibroma, four cases of extragonadal germ cell tumours, two cases each of thymic cyst, bronchogenic cyst, retrosternal goitre, ganglioneuroma and neuroblastoma, and one case each of lipoma and thymolipoma. FNAC was done in 54 cases of which 7 cases yielded inadequate material. Immunohistochemistry was required for classification of lymphoma cases and confirmation of a mixed component in germ cell tumours. Conclusion: Mediastinal masses create significant diagnostic dilemma for the clinicians, radiologists and histopathologists. While imaging studies help in narrowing the differential diagnosis, accurate categorisation is not always possible. FNAC is a useful and cost effective tool. However, sampling error and complexities in performing the technique are major hurdles in the usefulness of this diagnostic modality.

Keywords

• Mediastinum
• Thymoma
• Lymphoma
• Seminoma
• Neurogenic tumours