Aims: Desmoplasia, intratumoral lymphocyte infiltration, and calcification within the tumor and peritoneum are quite common in advanced epithelial ovarian carcinoma. Peritumoral inflammatory reactions associated with hematologic paraneoplastic syndrome are extremely rare. Materials and Method: We describe in detail two cases of epithelial ovarian carcinoma associated with proliferation of Russell bodies and Mott cells in desmoplastic tumor stroma. Results: In the first case, monoclonal proliferation was diagnosed with intranuclear inclusions (Dutcher bodies) in plasma cells. Dutcher bodies were seen both in the tumoral tissue and bone marrow. Monoclonal gammopathy of undetermined significance (MGUS) was diagnosed with an IgM level less than 3 g/l and clonal paratrabecular lymphoplasmocytoid infiltrate less than 10% in the bone marrow. There were no light chain restrictions. Elevated beta 2 microglobulin level and anemia complicated the patients' survival. In the second case, because of desmoplasia the tumor volume did not decrease after the standard chemotherapy although a significant portion of the carcinomatous tissue disappeared. In this study, we checked the role of peritumoral allergic response prospectively in five epithelial ovarian carcinoma cases by actin, desmin, and lambda light chain immunohistochemical staining of the omentum. Conclusions: Further studies are necessary to show the relation between peritumoral hypersensivity reaction and HLA 1 antigen processing machinery to improve disease-specific survival in epithelial ovarian carcinoma.