Primary Ovarian Mucinous Tumors With Signet Ring Cells

Abstract

The distinction between a primary ovarian mucinous carcinoma or even a borderline mucinous tumor and a metastatic mucinous carcinoma may be difficult. A constellation of clinical, gross pathologic and morphologic features is used in this distinction. One of the most important morphologic features suggesting a metastatic mucinous carcinoma in the ovary is the presence of signet ring cells; these are considered rare in primary ovarian mucinous tumors. In this study, we report 3 primary ovarian mucinous tumors with a component of signet ring cells. The tumors arose in patients aged 27, 55, and 60, were unilateral, confined to the ovary and stage IA. They ranged from 9 to 27 cm; 1 was grossly a multiloculated cystic lesion and 2 were cystic and solid. In one case, the neoplasm had the architecture of a mucinous adenofibroma but had frankly malignant cells lining glands and forming solid aggregates of cells. A second tumor also had the background of an adenofibroma. The third was mostly a mucinous cystadenoma. In one case, endometriosis was present in the same ovary; teratomatous elements were not identified in any case. Immunohistochemistry, performed in 2 cases, showed both to be diffusely positive with CK7 and CA19.9, including the signet ring cells. CK20 was positive in both cases (1 focal; 1 diffuse). Estrogen receptor and CA125 were diffusely positive and carcinoembryonic antigen and CDX2 focally positive in 1 case. Chromogranin and synaptophysin were negative. Investigations to exclude a gastrointestinal neoplasm in 2 cases were negative. Features favoring a primary rather than a metastatic neoplasm are unilateral tumor, low stage, background of adenofibroma or cystadenoma, associated endometriosis in 1 case and an absence of features which are characteristic of secondary mucinous carcinomas in the ovary, such as surface tumor deposits, a nodular growth pattern, and lymphovascular permeation. Immunohistochemistry is of limited value because of overlapping immunophenotype between a primary ovarian mucinous tumor and a metastasis from the stomach, pancreas, biliary tree, appendix, or colorectum, the most likely primary sites for a secondary exhibiting similar features. Our study illustrates that signet ring cells occur rarely in a primary ovarian mucinous tumor; even when conspicuous the features differ from those of the usual Krukenberg tumor. At least some cases of so-called primary Krukenberg tumor may be similar to our cases. However, the designation primary Krukenberg tumor should not be used as, apart from the signet ring cells, a resemblance to a "true" Krukenberg tumor of the secondary type is limited. The tumors should be classified according to the underlying background neoplasm with a notation concerning the signet ring cell component.

Primary Signet Ring Cell Mucinous Ovarian Carcinoma: A Case Report and Literature Review

“…One of the reported tumours was a mucinous cystadenoma with a focal development of signet ring cell carcinoma. The other 2 tumours were mucinous adenofibromatous tumours with a focal signet ring cell carcinoma [5]. …”

“…Thus, the finding of a signet ring cell carcinoma in an ovary can no longer be classified as a metastatic tumour. On the contrary, it is necessary to distinguish the ‘real’ Krukenberg tumour, a signet ring cell carcinoma of the ovary, from secondary malignancies by thorough examination of the gastrointestinal organs, excluding the occurrence of other primary tumours [5]. This approach is necessary to ensure proper treatment of these tumours, including surgery and consecutive chemotherapy.…”

“…Moreover, there should be no evidence of metastatic tumour like bilateral tumour, deposits on the surface, nodular growth in microscopic and macroscopic examinations, extensive lymphovascular permeation, destructive stromal invasion, or tumour cells floating in mucin or extraovarian spread, although none of these would exclude this diagnosis [5, 9]. …”

“…The description of a primary Krukenberg tumour or a second type of Krukenberg tumour has amply been discussed in the literature [5, 14]. …”

“…In the past few years, there were reports of 13 cases of primary ovarian stromal tumours with signet ring cells. Most of these were benign but 3 cases were primary mucinous signet ring cell carcinomas of the ovary [4, 5]. …”