LCNC (large cell neuroendocrine carcinomas) of the ovary is a rare aggressive tumor entity of the genital tract. Its pathogenesis, origin, and prognosis have not been fully elucidated, since there are a limited number of cases reported in literature. We report a case of an 80-year-old patient, who presented with a growing abdominal mass, which turned out to be a mixed LCNC/epithelial neoplasm. Although this type of tumor is rare, the continuous development of pathologoanatomy and immunohistochemistry contributes to our better knowledge and comprehension of these neoplasms.