ABSTRACT

We present a patient having an endometrial carcinomawith an incidental finding of hilus cells in the tuba ute-rina. To our knowledge this is the first report of an in-cidental finding of hilus cells in the fallopian tube coin-cident with an endometrial carcinoma. No gross abnor-mality was seen in the salpinges, but microscopic exami-nation showed scattered aggregates of hilus cells bene-ath a normal tubal epithelium. Both ovaries showedprominent hilus cells in the hilus also. Immunohistoche-mical findings were as follows; inhibin, calretinin, Me-lan A, vimentin were positive and EMA, CD99 were ne-gative. Both microscopic and immunohistochemical fe-atures were identical to hilus cells of the ovary. So im-munohistochemistry may be a useful tool to differentia-te the extra-ovarian hilus cells from their mimics.

Key words: Hilus cell, endometrial carcinoma, immu-nohistochemistry, tuba uterina

ÖZET

Endometriyum adenokarsinomu olan bir hastada rast-lant›sal olarak tuba uterinas›nda hilus hücreleri sapta-nan bir olgu sunulmaktad›r. Bildi¤imiz kadar›yla olgu-muz literatürde tuba uterinas›nda hilus hücreleri sapta-nan endometriyum karsinomlu ilk olgu sunumudur.Makroskopik olarak hiç bulgu saptanmamakla beraber,mikroskopik incelemede normal tuba epiteli alt›nda kü-meler halinde yay›lm›fl hilus hücreleri görüldü. Ayr›caher iki over hilusunda da yayg›n hilus hücreleri vard›.‹mmünhistokimyasal olarak inhibin, kalretinin, MelanA, vimentin pozitif ve EMA, CD99 ise negatif olarak sap-tand›. Hem mikroskopik hem de immünhistokimyasalbulgular, overin hilus hücreleri ile özdeflti. ‹mmünhisto-kimya over d›fl› hilus hücrelerini benzerlerinden ay›r-mak için yararl› bir araç olarak kullan›labilir.

Anahtar sözcükler: Hilus hücresi, endometriyal karsi-nom, immünhistokimya, tuba

INTRODUCTION

Hilus cells are ovarian counterpart of testi-cular Leydig cells, with the exception of femalechromatine pattern. These cells are round tooval and may contain crystals of Reinke (1). Hi-lus cells are present during fetal life, not identi-

fied in childhood but reappear at puberty and aredemonstrable in all postmenopausal women atthe hilar region of the ovary (2). Few cases ha-ve reported the existence of hilus cells outsidethe ovarian hilus, especially in the fallopian tu-be (3,4,5). None of the cases reported in the li-terature were associated with a neoplastic pro-cess. We present a patient having an endometri-al carcinoma with an incidental finding of hiluscells in the tuba uterina.

Hilus cells in tuba uterina; an uncommon localisation and coincidence with endometrialcarcinoma: A case report and review of the literature

Tuba uterina’da hilus hücreleri; s›rad›fl› bir yerleflim veendometriyal karsinom ile birliktelik: Olgu sunumu ve literatürün gözden geçirilmesi

Alp USUBÜTÜN

Hacettepe Üniversitesi T›p Fakültesi Patoloji Anabilim Dal›, ANKARA

Corresponding Author: Dr. Alp Usubütün, Hacettepe Üniversite-si T›p Fakültesi Patoloji AD S›hhiye 06100, Ankara

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Turkish Journal of Pathology 2007;23(1):52-55

CASE REPORT

A sixty-six-year old woman referred to ourhospital because of her endometrial carcinoma.She had an abdominal pain and vaginal bleedingfor 2 months and the endometrial biopsy thatwas done in another center had reported grade 1,endometrioid type endometrial carcinoma. Shehad diabetes mellitus and otherwise was a he-althy woman. Serum CEA, CA15.3, CA 19.9and CA125 levels were normal. Total hysterec-tomy, bilateral salpingo-oophorectomy, pelvicand paraaortic lymphadenectomy and omentec-tomy were done.

On macroscopic examination, the uteruswas 145 gr in weight and 8.5x4.5x4 cm in size.

Cut section of the uterus showed a tumorwith both polipoid and infiltrative features. Thedepth of tumor infiltration measured 1.5 cm in

the myometrium and the intact myometriumwas 0.5 cm in this area. No other gross abnor-mality was detected including the salpinges,ovaries, omentum and lymph nodes. Both sal-pinges were sampled completely by cuttingthem into two along the long axis.

No omental and lymh node involvementwas detected. The interesting finding detectedon left salpinx was aggregates of hilus cells onthe fimbrial part. These aggregates were scatte-red beneath a normal tubal epithelium (Figure1A). The cells forming these aggregates werelarge with oval to round eosinophilic cytoplasmand vesicular nuclei containing prominent nuc-leoli (Figure 1B). No prominent atypia or mito-sis was found. These hilus cell aggregates wererich in vascular structures. Both ovaries alsoshowed prominent hilus cells in their hili as se-en in some postmenopausal cases. (Figure 1C).

Figure 1. a) Aggregates of hilus cells were scattered beneath the tubal epithelium (x40). b) The cells have large oval or round eosi-nophilic cytoplasm and vesicular nuclei containing prominent nucleoli (x400). c) Both ovaries showed prominent hilus cells in the hi-lus (x200). d) A well differentiated endometrioid carcinoma of the endometrium (x40).

a b

c d

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Hilus cells in tuba uterina; an uncommon localisation and coincidence with endometrial carcinoma: A case report and review of the literature

Microscopic examination revealed a well diffe-rentiated endometrioid carcinoma of the endo-metrium, with more than one half infiltration ofmyometrium and without endocervical involve-ment (Figure 1D). Immunohistochemical fin-dings were as follows; inhibin (1/25, Serotec),calretinin (1/100, NovoCastra), Melan A (1/100,Neomarkers), Vimentin (1/500, Neomarkers)were positive and EMA (1/100, Neomarkers),CD99 (1/100, Neomarkers) were negative (Fi-gure 2).

DISCUSSION

Hilus cells are ovarian counterpart of testi-cular Leydig cells, with the exception of femalechromatine pattern. Hilus cells are present du-ring fetal life, not identified in childhood but re-appear at puberty and are demonstrable in all

postmenopausal women (2). Hilus cell aggrega-tes are typically found in the ovarian hilus. Fewcases were reported with the existence of hiluscells in the fallopian tube (3,4). Apart from the-se case reports and another study detecting thepresence of hilus cells in fallopian tube (5) noother article has appeared on that topic in theEnglish written literature. Also, to our knowled-ge this appears to be the first report of an inci-dental finding of hilus cells in the fallopian tubecoincident with an endometrial carcinoma.

The morphologic similarity of hilus cellswith adrenal rest cells may be a diagnostic chal-lenge in some cases. The presence of Reinkecyristals may be a clue for the hilus cells, butimmunohistochemical features are quite charac-teristic. Staining pattern of these hilus cells aresimilar to ovarian hilus cells and other sex-cordstromal tumors such as positive staining with in-

Figure 2. The hilus cells were immunohistochemically stained with; inhibin (a), calretinin (b), Melan-A (c), Vimentin (d).

a b

c d

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Turkish Journal of Pathology 2007;23(1):52-55

hibin, vimentin, melan A, calretinin and negati-ve staining with EMA. In contrast to hilus cells,adrenal rests are usually positive with neuroen-docrine markers. This staning characteristics al-so helps differentiate epithelial tumor from hiluscell aggregates. Epithelial tumors are usuallypositive with EMA and almost always negativewith other markers.

To our knowledge this appears to be thefirst report of an incidental finding of hilus cellsin the fallopian tube co-incident with an endo-metrial carcinoma. It is a well known fact thatwell differentiated endometrial carcinomas areassociated with estrogens. Hilus cells are stero-id hormone producing cells, although to whatextent hilus cells contribute to the steroid hor-mone pool is unknown (1). The major productof hilus cells is the androstenedione, but smallamounts of E2 and P are also produced (1). In astudy of hysterectomy/oopherectomy specimenswith non-neoplastic uterine lesions done in 1971found that fifty two percent of fallopian tubescontain ectopic hilus cells (5). Although, thereare some reports implying the association bet-ween hilus cell hyperplasia of the ovary and en-dometrial carcinoma (6), this is the first reportimplying the association between well differen-tiated endometrial carcinoma and extra-ovarianhilus cells.

The origin of hilus cells in the fallopian tu-be is a mystery. It is theorized that ovarian hilus

cells originated from undifferentiated ovarianmesenchyme, non myelinated nerve or perineu-ral fibroblast. Lewis suggested that during emb-ryologic development some ovarian mesench-ymal cells might migrate into the mullerianducts (3). Some others defined these lesions asheterotopia (5).

Whatever the origin, the presence of hiluscells in the fallopian tube is an incidental fin-ding. Both microscopic and immunohistochemi-cal features are identical to hilus cells of theovary. So immunohistochemistry may be a use-ful tool to differentiate the extra-ovarian hiluscells from their mimics. Co-existence of the hi-lus cells in the tuba uterina of the patients ha-ving an endometrial carcinoma may be subjectof further research.

REFERENCES

1. Clement PB. Anatomy and Histology of the Ovary,(In) Kurman RJ ed. Blaustein’s Pathology of the Fema-le Genital Tract 5th ed., New York, Springer Verlag,2001. p.649-673.

2. Sternberg WH. The morphology and androgenic func-tion, hyperplasia and tumors of human ovarian hiluscells. Am J Pathol 1949;25:493-521.

3. Lewis JD. Hilus-cell hyperplasia of ovaries and tubes:Report of a case. Obstet Gynecol 1964;24:728-731.

4. Palomaki JF, Blair OM. Hilus cell rest of the fallopiantube. A case report. Obstet Gynecol 1971;37:60-62.

5. Honore LH, O’Hara KE. Ovarian hilus cell heteroto-pia. Obstet Gynecol 1979;53:461-464.

6. Mohamed NC, Cardenas A, Villasanta U, Toker C,Ances IG. Hilus cell tumor of the ovary and endomet-rial carcinoma. Obstet Gynecol 1978;52:486-490.

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Hilus cells in tuba uterina; an uncommon localisation and coincidence with endometrial carcinoma: A case report and review of the literature