INTRODUCTION

An uterus-like mass is a very rare conditi-on that was first described by Cazutto in 1981(1). This lesion was characterized by a centralcavity lined with endometrial and tubal typemucosa surrounded by thick bundles of smoothmuscle cells. Many cases of uterus like masswere reported under various terms such as ade-nomyoma, endomyometriosis and tumor ofmüllerian type since 1981 (2-5). Although, his-togenesis of this lesion remains unknown, seve-ral hypotheses have been proposed. We herebyreport an incidental lesion arising from the rightovary mimicking a miniature uterus.

CASE REPORT

A 54-year-old woman who had pelvic pa-in and postmenstrual bleeding was admitted toGynecology and Obstetrics Department of Do-kuz Eylul University Medical Faculty hospital.The patient had undergone abdominal histerec-tomy with bilateral salphingo-oopherectomywith a clinical diagnosis of myoma uteri.Theuterus weighed 250 g and measured 10x6x5 cm.The cavity was well developed with a singlehorn extending to the left side. The thickness ofendometrium was 2 mm. Both ovaries were wit-hin normal dimensions. The cut surfaces revea-led white areas concordant with corpus albicansand both ovaries had cystic lesions measuringless than 10 mm. Both tubae uterina were nor-mal in appearance. The myomectomy material

ABSTRACT

We report an incidental case of uterus-like mass locatedin the right ovary. A mass, measuring 7 mm in its lar-gest dimension was noted in the right ovary of a 54-ye-ar-old women. Histologically, the lesion was resemblinga miniature uterus with a cavity lined by a tubal-likeepithelium, and surrounded with circumscribed smoothmuscle bundles. Since 1981, 8 cases of uterus-like massarising from the ovaries have been reported and theirpathogenetic mechanism has been explained by two ba-sic theories; congenital anomaly and metaplasia. Thepresent case was incidentally found. The uterus wasunicornus secondary to fusion defect of müllerian ductduring embriogenesis supporting the congenital ano-maly theory.

Key words: Uterus-like mass, ovary, congenital ano-maly

ÖZET

Elli dört yafl›nda kad›n hastan›n total abdominal histe-rektomi ve bilateral salfingoooferektomi materyalinde,rastlant›sal olarak saptanan sa¤ ovaryum yerleflimliuterus benzeri kitlesel lezyon sunulmaktad›r. Histolojikincelemede lezyonun, tuba epiteline benzer epitel ile dö-fleli kaviter alan› çevreleyen sirküler yerleflimli kal›ndüz kas demetlerinden olufltu¤u, minyatür bir uterusabenzedi¤i, 7 mm çapl› ve iyi s›n›rl› oldu¤u saptanm›flt›r.Literatürde ovaryum kökenli uterus benzeri kitlesellezyon olarak tan›mlanan 8 olgu yay›nlanm›flt›r. Bu lez-yonlar›n gelifliminde konjenital anomali ve metaplazi te-orileri öne sürülmüfltür. Olgumuzda, uterus kavitesinintek kornulu oluflu nedeniyle, gelifliminin embriyogenezsürecinde müllerian duktusun füzyon bozuklu¤unaba¤l› konjenital anomali fleklinde geliflti¤i düflünülmüfl-tür.

Anahtar sözcükler: Uterus benzeri kitle, ovaryum,konjenital anomali

Uterus-like mass of the ovary

Ovaryumun uterus benzeri kitlesel lezyonu

Duygu GÜREL, Burçin TUNA, Kutsal YÖRÜKO⁄LU

Dokuz Eylul University, Faculty of Medicine, Department of Pathology, ‹ZM‹R

Corresponding Author: Dr. Duygu Gürel, Dokuz EylulUniversity, Faculty of Medicine Department of Pathology, ‹zmir

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was white to green with a whorled cut surface,measuring 7x7x6 cm. Histopathologically, thecervix showed non-specific inflammatory chan-ges. The endometrium was in proliferative pha-se and myometrium contained an adenomyoticfocus. The described solid mass revealed typicalmicroscopic features of a leiomyoma. Both ova-ries had cystic follicules and corpora albicantia.Besides these, a nodular lesion localized withinthe ovarian stroma in close proximity to corpo-ra albicantia was observed in the right ovary.Microscopically, this lesion measured 7 mm indiameter and composed of tubal-like mucosaand circular, thick smooth muscle bundles (Fi-gures 1 and 2).

DISCUSSION

Uterus-like mass of the ovary is a uniqueentity. Since 1981, 8 cases of ovarian uterus- li-ke mass have been reported (1,4,6-9). In additi-on, extra-ovarian cases localized in the broad li-gament, small bowel, small bowel mesentery,lumbosacral region, conus medullaris, loweruterine segment, uterosacral ligament, paratesti-cular region, left obturatory lymph node, uterinecervix, and vaginal cuff wall were also descri-bed. Their sizes ranged from 4 to 16 cm withgross cystic and solid areas. Furthermore, anelevated CA125 level (4,10) (two cases), an as-sociated breast carcinoma (4) (two cases), endo-metrioid carcinoma (7) (one case), uterine lipo-leiomyoma (11) (one case), lipoma (12) (one ca-se), clonal chromosome deletion 2p21 (8) (onecase), receiving estrogen therapy (10, 19) (2 ca-ses,) and associated congenital anomalies(1,6,12) were also reported. Close relationshipof this lesion with elevated serum levels of CA125, associated neoplasms and estrogen therapysuggested the role of hormones in the pathoge-nesis of this lesion.

Histogenesis of uterus-like mass has notbeen clarified yet. However, two basic theorieshave been suggested. These are congenital ano-maly and metaplasia theories (1,4,6-9,11,12,15).Also, heterotopia or choristoma theory was pro-posed by Peterson et al (18).

Congenital anomaly theory was favoredby the presence of congenital organ abnormali-ties such as uterine or renal systems in severalcases (1,3,9). Rosai et al. (13) suggested that thelesion reported by Cozzutto in 1981 as the firstuterus- like mass, represented uterine tissue thatwas anatomically separate from the uterine cor-pus, not related with ovarian tissue. It was pro-bably an example of uterine unicornis, associa-ted with a rudimentary detached uterine horn inthe contralateral adnexial region, representingMüllerian duct fusion defect or true partial dup-lication of the müllerian system (13). Formationof female genital tract depends on the müllerian

Figure 1. Microscopic appearance of uterus-like mass local-ized in the stroma of the ovary (HE x10).

Figure 2. Cavity lined by tuba uterine like mucosa and sur-rounding thick and organized bundles of smooth muscle(HE x40).

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duct fusion of three separate portions from cra-nial to caudal during the embryonal develop-ment (14). Developmental anomaly of müllerianduct fusion in various sides or throughout thelength of the duct may explain various duplica-tions or atresias of the uterus. A case was sug-gested to be due to partial atresia of one of themüllerian ducts resulting in a uterine appendixwhose central cavity did not connect with thevagina (6).

The metaplasia hypothesis attributes thehistogenesis of the uterus like mass to endomet-riosis with subsequent smooth muscle metapla-sia or to endomyometrial metaplasia resultingdirectly from the subcoelemic mesenchymetransformation. A case of uterine like mass ari-sing in the broad ligament was suggested to ari-se from subperitoneal mesenchymal cells thatretained the ability to duplicate müllerian duct(14,15). The subcoelomic mesenchyme (secon-dary müllerian system) is defined as the layer oftissue that lies underneath the mesothelial surfa-ce of the peritoneum (14,17). These tissues mayproliferate in response to hormonal stimulation.A vital initiating role of the hormones in the pat-hogenesis of these lesions was suggested (4,17).A close relationship with breast cancer and ele-vated serum CA125 level was found. The essen-tial role of hormones in the development of thelesions was supported by the development ofuterus- like mass in the scrotum of men who re-ceived estrogen therapy for prostatic carcinoma(19). Also, abundant expression of estrogen andprogesterone receptors in all cell types of themass is reported (20). Furthermore, such massesin the ovary without any congenital anomaliesof uterus or renal system were also describedsupporting the metaplasia theory (7,8).

Heterotopia theory was proposed by Peter-son et al (18). They noted that neither the con-genital nor the metaplasia theory was satisfac-tory for the explanation of some of the uterus-like masses. They reported an ileal uterine likemass that had morphological features of uterusand two smaller tubes like contiguous nodules

and various associated anomalies.The present case supports the rudimentary

horn concept. The uterus had a well formed ca-vity with a single horn extending to the left sideand a small uterine like mass was localized towithin the contralateral adnex. Also, a relativelysmaller, well-organized mass lesion localizedwithin ovarian tissue without any relation tosubperitoneal mesenchyme might suggest thelesion to be a rudimentary horn secondary to lo-calized fusion defect of müllerian ductal system.

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