Peritoneal dissemination of follicular carcinoma arising from struma ovarii in a pregnant woman

Abstract

Struma ovarii is defined as a rare monodermal form of ovarian teratoma that occupies more than 50% of thyroid tissue. Only 2% of struma ovarii display malignant histology, most of which is revealed as papillary carcinoma type. Follicular carcinoma originating from malignant struma ovarii is rarely reported. We report a case of a pregnant woman diagnosed with peritoneal dissemination of follicular carcinoma arising from struma ovarii.Keywords: Struma ovarii; Follicular carcinoma; Peritoneal dissemination; Pregnancy Received: 2012.5.25. Revised: 2012.6.22. Accepted: 2012. Corresponding author: Jae Hoon Kim, MD Department of Obstetrics and Gynecology, Gangnam Severance Hospital, Yonsei University College of Medicine, 211 Eonju-ro, Gangnam-gu, Seoul 135-720, Korea Tel: +82-2-2019-3436 Fax: +82-2-3462-8209 E-mail: jaehoonkim@yuhs.ac This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2012. Korean Society of Obstetrics and GynecologyThe frequency of histological detection of thyroid tissue in ovarian mature teratoma is less than 20%, while that of a macroscopic detection is less than 3% [1]. Struma ovarii is defined as a rare monodermal form of ovarian teratoma, which comprises of more than 50% of thyroid tissue [2]. Mature cystic teratoma is a benign tumor, 2% of which have been reported to be struma ovarii [3]. Histologic malignancy arising from struma ovarii has been rarely reported and its occurrence is less than 5% in struma ovarii. Most histologic malignancies arising from struma ovarii are papillary thyroid carcinoma, and account for 70%−85% of total cases [3,4]. Follicular carcinoma of histologic malignancy arising from struma ovarii is extremely rare. Here, an early pregnant woman with follicular carcinoma arising from struma ovarii is reported with a review of relevant literature. Case ReportA 33-year-old, pregnant woman with gravida 3, para 1 was referred under the impression of bilateral ovarian malignancy, which was detected incidentally via a routine sonography in early pregnancy. The patient had two surgical histories: laparoscopic right ovarian cystectomy of mature cystic teratoma, five years ago, and laparoscopic cholecystectomy of gall bladder stone, two years ago. Pelvic magnetic resonance imaging (MRI) revealed bilateral parovarian solid tumors near the pelvic sidewall and unusual manifestation of metastatic lesions in the pelvic cavity ( Fig. 1). On March 2, 2010, the patient underwent explolaparotomy under the impression of bilateral ovarian malignancy at 7 +6 weeks of intrauterine pregnancy. The patient had a slightly enlarged uterus appropriate for eight weeks gestational age, and the bilateral ovary and fallopian tube were normal in size and shape. About ten metastatic masses with pink color and rubbery consistency were observ...