Mature teratoma of the uterine corpus: A case report

Summary

We report a case of a 37-year old female with a mature teratoma of the uterine corpus presented by metrorrhagia. Grossly, the tumor was polypoid without apparent invasion into the myometrium. Microscopically, the tumor consisted of disorganized mature neural tissue intermingled with nodular foci of cartilaginous tissue, groups of seromucionous glands and ciliated columnar respiratory epithelium. Fifteen months after the diagnosis, the patient showed no signs of tumor relapse. Then she was lost for a follow-up. Teratoma of the uterine corpus is rare; to the best of our knowledge only about 20 cases have been reported to date.

Keywords:
teratoma – uterus – pluripotent stem cell – primordial germ cell

Teratomas are the most frequent type of germinal tumors. They can be either monodermal or they consist of two or three germ layers. Mature teratomas consist of differentiated adult-type tissues, while immature teratomas contain a variable portion of fetal or embryonal-type tissues (1). Most teratomas occur in gonads, but they can also arise extragonadally, especially in the sites of primordial germ cells migration along the body axis (from the pineal gland to the coccyx) (2). Rarely, teratomas can be found in other sites (3-5). We present a rare case of a mature teratoma arising in the uterine corpus (6-10).

CASE REPORT

A 37-year old female presented with metrorrhagia lasting for 9 days. The patient’s serology showed normal hCG level, and was referred for further treatment to the Department of Obstetrics and Gynecology, First Faculty of Medicine and General University Hospital in Prague. The initial transvaginal ultrasound revealed a nonhomogeneous partly polypoid vascularized mass, 30 mm in largest diameter, localized in the endometrium. Subsequently, the patient underwent a hysteroscopy with the resection of a polyp measuring 30 x 15 x 15 mm. A transvaginal ultrasound was performed 16 days later and showed normal findings. Fifteen months after the diagnosis, the patient showed no signs of tumor relapse. Then she was lost to follow-up.

MATERIALS AND METHODS

Sections from formalin-fixed, paraffin-embedded tissue blocks were stained with hematoxylin-eosin. Selected sections were analyzed immunohistochemically using the avidin-biotin complex method with antibodies against GFAP (clone 6F2, 1:1000, Dako, Glostrup, Denmark) and S100 protein (polyclonal, 1:1600, Dako, Glostrup, Denmark).

RESULTS

Grossly, the material consisted of several tissue fragments up to 30 x 15 x 5 mm.

Microscopically, the fragments were partly polypous and were composed of disorganized mature neural tissue intermingled with nodular foci of cartilaginous tissue, groups of seromucionous glands and ciliated columnar respiratory epithelium (Fig. 1A, B). Moreover, there were focal areas of mature neural tissue located in the surrounding endometrial stroma (Fig. 1C). Focally, a stratified squamous epithelium with hyperkeratosis was present on the surface of tissue fragments. Immunohistochemically, the neural tissue expressed GFAP and S100 protein (Fig. 1D). Expression of S100 protein was also present in cartilaginous tissue. The tumor was confined to the endometrium without any apparent invasion into the myometrium.

Our patient underwent enucleation of the mature cystic teratoma (dermoid cyst) of the left ovary 7 years before the diagnosis of the uterine teratoma.

DISCUSSION

Teratomas of the uterus are rare neoplasms usually located in the uterine cervix (11). Only 20 cases of teratoma arising in the uterine corpus have been reported to date (6-10). Most of them were mature teratomas. However, there are two reports of immature teratomas and one report of immature teratoma coexisting with adenocarcinoma (1,6). Teratomas of the uterine corpus are usually polypous lesions that present clinically by abnormal uterine bleeding. The origin of uterine corpus teratoma is not entirely clear. However, according to the current knowledge, these tumors probably arise from pluripotent stem cell or from primordial germ cell with erroneous migration (9).

Due to the rarity of uterine corpus teratoma, whenever there is a teratoma tissue present in a material from a uterine cavity curettage, it is necessary to exclude spreading from another site which is more frequently the origin of these tumors, particularly the ovaries. In females with a history of pregnancy the differential diagnosis also includes the implantation of fetal remnants.

Our patient underwent enucleation of the mature cystic teratoma (dermoid cyst) of the left ovary 7 years before the diagnosis of the uterine teratoma. We have not found any report of an ovarian teratoma relapsing in the uterine corpus in the literature. Due to the long interval between both diagnoses we consider it to be a tumor duplicity rather than a relapse. However, the possibility of relapse cannot be excluded as well.

In conclusion, we describe a case of a mature teratoma located in the uterine corpus. To the best of our knowledge only about 20 cases of uterine corpus teratoma have been reported to date. Despite its rarity, the possibility of teratoma should be kept in mind in differential diagnosis of tumors located in the uterine corpus. However, the possibility of spread of teratoma from more common primary location should be excluded in each such case.

CONFLICT OF INTEREST

The authors declare that there is no conflict of interest regarding the publication of this paper.

Correspondence address:

Jan Galko, MD

Department of Pathology, First Faculty of Medicine

and General University Hospital,

Charles University in Prague

Studničkova 2,

12800 Prague 2,

Czech Republic

tel.: +420224968630

fax: +420224911715

e-mail: jan.galko@vfn.cz