Author(s)

Tsutomu Muramoto^*, Kyosuke Kamijo, Megumi Sano, Yuki Ibuki, Atushi Mori, Yaeko Kobayashi

Nagano Municipal Hospital, Department of Obstetrics and Gynecology, Nagano, Japan.

We here present a rare case of appendiceal tumor mimicking ovarian tumor in menopause woman. The patient was a 56-year-old woman, G1P1, who presented to our hospital with a right adnexal cyst diagnosed at another hospital. Transvaginal echocardiography showed a cyst in the right adnexal region, and pelvic contrast-enhanced MRI revealed a small cyst in the same region. The left ovary was atrophic and identifiable. It was unclear whether the cyst was contiguous with the gastrointestinal tract. Blood tests showed no elevation of tumor markers. We considered its possibility of a gastrointestinal origin, but since right normal ovary was not found, we thought the tumor was of ovarian origin and decided on a laparoscopic resection of the right adnexa. Intraoperatively, we observed atrophied bilateral normal ovaries, and the pelvic tumor was contiguous to the appendix. Surgeons performed a laparoscopic appendectomy after consultation with us. After resection we searched the abdominal and pelvic cavities, but found no obvious disseminated lesions. The histological diagnosis was low-grade appendiceal mucinous neoplasm (LAMN), a rare benign tumor of the appendix. Appendiceal tumors can be difficult to differentiate from right ovarian tumors due to their close anatomic location in the pelvis. It is possible to determine whether the tumor is of ovarian or appendiceal origin by identifying normal ovaries and the location of the feeding vessels into the tumors. In our case, there were no lesions other than the appendix, but LAMN can metastasize to the ovary, cause pseudomyoxoma peritonei, or be an overlapping tumor with an ovarian tumor. If an appendiceal tumor is diagnosed after surgery for ovarian tumor, the intra-abdominal cavity should be searched for metastasis or dissemination, and a thorough search for ovarian lesions should be performed with the possibility of an overlapping tumor in mind.

Low-Grade Appendiceal Mucinous Neoplasm, Ovarian Tumor, Menopause Woman

Muramoto, T. , Kamijo, K. , Sano, M. , Ibuki, Y. , Mori, A. and Kobayashi, Y. (2022) A Case of Low-Grade Appendiceal Mucinous Neoplasm of Its Difficultly to Distinguish from a Right Ovarian Tumor Due to Postmenopause. Open Journal of Obstetrics and Gynecology, 12, 1140-1146. doi: 10.4236/ojog.2022.1211098.