Immunohistochemical analysis using cell block technique leads accurate diagnosis of ovarian malignant lymphoma: A case report.

• Treatment of ovarian malignant lymphoma is based on chemotherapy, although radical surgery improves prognosis of epithelial ovarian cancer. • Immunohistochemical analysis using cell block technology helped us establish an accurate diagnosis of ovarian lymphoma. • Abdominocentesis followed by cell block analysis is very useful for identifying ovarian malignancy before radical invasive operation. Ovarian malignant lymphoma is a rare gynecologic disease and some patients show marked ascites, similar to that observed in advanced ovarian cancer. Although radical surgery improves prognosis of ovarian cancer, treatment of lymphoma is based on chemotherapy, therefore, differential diagnosis is crucial. A 65-year-old woman presented with a 1-month history of abdominal distention. Pelvic ultrasonography showed an 11-cm solid mass in the pelvis. Computed tomography and magnetic resonance imaging revealed bilateral (mainly left) ovarian masses in the pelvis and multiple metastases. Laboratory examination revealed that serum CA125 levels were elevated, suggesting the existence of advanced ovarian cancer. To confirm the diagnosis, the ascites was removed via abdominocentesis. Although no malignant epithelial cells were observed, atypical lymphoid cells dispersed in the ascites were detected in the cytological analyses. Thus, for accurate diagnosis, we performed re-abdominocentesis and immunohistochemical (IHC) analysis using cell block technique. Cell block analysis showed negative staining for CD3 and positive staining for CD20 in large atypical lymphoid cells, suggesting the existence of large B-cell lymphoma. Repeat blood examination showed that the serum sIL-2R level was elevated. We decided to perform biopsy to make the final treatment decision. Histologically, the tumor demonstrated diffuse proliferation of large atypical lymphoid cells. IHC analysis showed CD3(-), CD5(+), and CD20(+). In addition, IHC analysis also showed CD79a(+), CD10(-), bcl-2(+), and cyclin D1(-). The final diagnosis was diffuse large B-cell lymphoma. Here, we present the case of a patient with ovarian malignant lymphoma that was diagnosed using cell block analysis. [ABSTRACT FROM AUTHOR]