Aggressive T-cell lymphoid neoplasm presenting as a left adnexal mass mimicking advanced epithelial ovarian carcinoma: a case report and focused narrative literature review

Background Ovarian involvement by T-cell lymphoid neoplasms is exceptionally rare and can closely mimic advanced epithelial ovarian carcinoma. Distinguishing between them is clinically important because lymphoid neoplasms require subtype-specific systemic therapy rather than ovarian cytoreductive surgery; therefore, adequate tissue diagnosis should be pursued by the least invasive feasible method when lymphoma is considered. Case presentation A 43-year-old woman presented with progressive asthenia, a 12-kg weight loss, abdominal distension, and pain. Physical examination revealed a large abdominopelvic mass. Laboratory findings included elevated CA-125 (195 U/mL), markedly elevated LDH (1,482 IU/L), elevated C-reactive protein, and hypoalbuminaemia. Imaging showed a 17-cm left adnexal mass, ascites, peritoneal thickening, splenomegaly, and a bulky retroperitoneal nodal conglomerate causing bilateral hydroureteronephrosis, raising strong suspicion of advanced ovarian carcinoma while also prompting consideration of lymphoma. Diagnostic laparoscopy revealed no macroscopic peritoneal carcinomatosis or omental caking. A left adnexectomy was performed for decompressive and diagnostic purposes after image-guided biopsy had been considered but was unavailable. Histopathology demonstrated an aggressive T-cell lymphoid neoplasm, with diffuse strong CD3 expression and negative CD20 and pancytokeratin AE1/AE3; no definitive lymphoma subtype could be assigned because ancillary studies were not completed. Before complete staging and lymphoma-directed systemic therapy could be initiated, the patient rapidly deteriorated and died on postoperative day 25; the immediate cause of death was not established. Conclusion Aggressive lymphoid neoplasms presenting as an adnexal mass can visually and radiologically mimic advanced ovarian carcinoma. Markedly elevated LDH, bulky retroperitoneal lymphadenopathy, ureteric encasement, splenomegaly, and discordance between imaging and laparoscopic findings should raise suspicion for a lymphoid malignancy but are not pathognomonic. Rapid acquisition of adequate tissue for comprehensive pathological and haematopathological assessment is important, and definitive surgery should be avoided when a less invasive diagnostic approach is feasible.