Experience with Orbital Tumors from a Tertiary Cancer Centre of North East India: A Pathology Perspective.

The orbit is an anatomically complex structure comprising the globe, extraocular muscles, fat, vascular, nervous, glandular, and connective tissues. A wide variety of neoplasms can arise from different orbital structures, which can create a diagnostic challenge to the pathologists. No formal study has been conducted in this regard in North East India.  This article aims to document the pattern and prevalence of orbital tumors in our institute and assess the utility of histopathological examination (HPE) and immunohistochemistry (IHC) in the precise diagnosis of these neoplasms.  A retrospective analysis of orbital tumors was performed over a period of 5 years from 2013 to 2018 in the department of pathology at a tertiary cancer center of North East India following all the guidelines of the institutional ethics committee.  A total of 35 cases of orbital neoplasms, evaluated by HPE and IHC, were found, all of them being malignant tumors. The age range was 4 months to 85 years. Male to female ratio was 1.5:1. The most common tumor found was lymphoma, accounting for 10 cases (28.6%), all of which were non-Hodgkin lymphoma (NHL). All these cases except one occurred in adults, thus making it the most common tumor in adults in this study. Diffuse large B cell lymphoma, not otherwise specified, was the most common NHL, followed by follicular lymphoma, mature T cell NHL, extranodal marginal zone lymphoma, and B cell lymphoblastic lymphoma. Rhabdomyosarcoma and poorly differentiated/undifferentiated carcinoma jointly were the second most common tumors, totaling seven cases (21.21%) each. This was followed by melanoma (three cases), myeloid sarcoma (three cases), Ewing sarcoma/peripheral neuroectodermal tumor (PNET) (three cases), neuroblastoma (one case), and angiosarcoma (one case). Among these, rhabdomyosarcoma, granulocytic sarcoma, Ewing sarcoma/PNET, and neuroblastoma exclusively troubled the children. IHC markers including the lymphoma panel, and soft tissue ones were crucial in the precise diagnosis of the neoplasms encountered.  A variety of malignant orbital tumors may be seen in clinical practice. Management of these tumors requires a multidisciplinary approach. HPE in conjunction with IHC evaluation is of utmost importance in the veracious recognition of orbital tumors for their proper management.