Primary Ovarian Non-Hodgkin Lymphoma- A Diagnostic Challenge with Clinicopathological: Clinicopathological Study of Eight Cases

Introduction: The involvement of the Female Genital Tract (FGT) by lymphoma is extremely rare, with ovaries being most commonly affected. Less than 1% of lymphomas present with ovarian involvement and less than 1.5% of ovarian neoplasms are of lymphoid origin. Secondary involvement of ovary by systemic lymphoma is more common than Primary Ovarian Lymphomas (POL) which is usually Primary Ovarian Non-Hodgkin lymphoma (PONHL) of B-cell lineage. Aim: To understand the clinicopathological and immunomorphological features of Primary Ovarian Non-Hodgkin lymphoma. Materials and Methods: This was a descriptive retrospective study conducted at Department of Pathology, Kidwai Memorial Institute of Oncology, Bengaluru, Karnataka. India, for a duration of 14 years between July 2006 to June 2020. Eight cases of PONHL were identified from departmental archives and clinicopathological and Immunohistochemistry (IHC) findings of these tumours were analysed. Results: The PONHL constituted 0.4% of all Non-Hodgkin lymphoma (NHL) reported during the study period. The patients age ranged from 13-60 years with a mean age of 34 years. Among eight cases of PONHL, two cases were of Diffuse Large B-Cell Lymphoma (DLBCL), followed by one case each of High-Grade B-Cell Lymphoma, Not Otherwise Specified (HGBL, NOS), Follicular Lymphoma (FL), Burkitt Lymphoma (BL), Plasmablastic Lymphoma (PBL), Precursor B-Lymphoblastic Lymphoma (B-LBL), and precursor T-Lymphoblastic Lymphoma (T-LBL). Seven cases were staged IE (Ann Arbor staging system) while one case was designated as stage IIE. Conclusion: This was probably the first study on PONHL from India. The diagnosis of PONHL is challenging unless there is a high index of suspicion as these patients present with non specific pelvic symptoms and can be misdiagnosed as other epithelial, stromal or germ cell ovarian neoplasm which differs in treatment and prognosis. Histological examination with IHC and molecular testing are essential to establish a diagnosis.