|LETTER TO THE EDITOR
|Year : 2015 | Volume
| Issue : 4 | Page : 1046
Pure epidermoid cyst of ovary
S Veena, PM Vijay, S Sowmya
Department of Pathology, HIMS and SIMS, Karnataka, India
|Date of Web Publication||15-Feb-2016|
Department of Pathology, Shimoga Institute of Medical Sciences, Shimoga - 577 201, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Veena S, Vijay P M, Sowmya S. Pure epidermoid cyst of ovary. J Can Res Ther 2015;11:1046
Epidermoid cysts of the ovary are exceptionally rare and are lined exclusively by mature stratified squamous epithelium and are distinguished from mature cystic teratomas of the ovary by the absence of skin adnexae and other tissues after thorough sampling.  The possibility that some of these lesions are actually mature cystic teratomas in which the skin adnexal components were missed or absent (mature monodermal teratomas) cannot be totally discounted. 
A 65-year-old postmenopausal women underwent hysterectomy and bilateral salpingoophorectomy in November 2012. She presented to out-patient department with a history of mass per abdomen and was further evaluated, pelvic examination showed a palpable mass on the left side, which was followed by ultrasonography which showed solid tumor of ovary. Carcinoma antigen 125 was within the normal limits. Hysterectomy and bilateral salphingoophorectomy was done. There were no adhesions to surrounding structures intra-operatively. The uterus, cervix measured 10 cm × 7 cm × 2.0 cm. The right ovary measured 4 cm × 1.0 cm × 0.8 cm and the tube 5 cm × 0.4 cm. The left ovary measured 14 cm × 8 cm × 4 cm and the tube measured 5 cm × 0.4 cm. On sectioning, the right ovary was unremarkable. Cut section of Left ovary showed unilocular cyst filled with keratin material. Representative sections were taken for study.
On histological examination, endometrium showed benign non-secretory phase, myometrium showed Monckebergs medial calcific sclerosis of vessels. Cervix showed non-specific cervicitis. Both fallopian tubes were unremarkable. Right ovary showed stromal hyperplasia. Sections from left ovarian cyst wall showed benign stratified squamous epithelium. No skin adnexae (hair follicles sebaceous glands) were seen. However, extensive keratin was seen in the lumen and calcification was also noted [Figure 1] and [Figure 2]. The left ovary was then regressed and submitted entirely for histologic examination. However, no skin adnexae or any other tissues were found [Figure 3]. Therefore, the lesion in the left ovary was reported as epidermoid cyst. We followed up the patient up to 6 months during which time she was doing well and advised her for regular follow-up.
|Figure 3: Microscopy showing keratinized stratified squamous epithelium, with no adenexal structures|
Click here to view
These rare lesions have been reported from around the world and almost uniformly represent incidental findings in the study of hysterectomy specimens.  The earliest cases were reported by Nogales and Silverberg in 1976  and they suggested that metaplasia of the coelomic surface epithelium of the ovary was involved in the histogenesis of these lesions. Young et al. described  cases in 1980 and after making a comparative study of these lesions, walthard nests and epithelial components of Brenner tumors suggested that epidermoid cysts originate from epithelial cell nests of the type encountered in Brenner tumors. Fan et al.,  in their series of eight cases suggest that ovarian epidermoid cysts represent monodermal and highly differentiated teratomas and should be classified as such. They also believe that epidermoid cysts of the ovary are not as rare as the literature suggests and some are probably misdiagnosed as dermoid cysts. Recently, more case reports have been published.  Peters et al.,  reported an epidermoid cyst of the ovary in combination with a well-differentiated endometroid adenocarcinoma of the ovary. The carcinoma had some foci of squamous metaplasia, but there was no continuity between the wall of the epidermoid cyst and the squamous metaplasia of the carcinoma. The authors were suggested that their case highlighted the still unsolved question about the origin of epidermoid cysts and added to the hypothesis that these cysts arise from pluripotent coelomic epithelium. Malignant transformation in mature teratoma is rare, occurring in only 1-2% of cases.  In our case, the epidermoid cyst in left ovary was associated with stromal hyperplasia in right ovary.
| > References|| |
Female Reproductive System. Ovary. In: Rosai J, editor. Rosai and Ackerman's Surgical Pathology. 9 th
ed. Amsterdam, Netherland: Elsevier; 2004; p. 1689-90.
Fan LD, Zang HY, Zhang XS. Ovarian epidermoid cyst: Report of eight cases. Int J Gynecol Pathol 1996;15:69-71.
Pezzica E, Buzzi A, Crescini C. Epidermoid cysts of the ovary. Presentation of a case of unusual dimensions. Minerva Ginecol 1991;43:265-6.
Nogales FF Jr, Silverberg SG. Epidermoid cysts of the ovary: A report of five cases with histogenetic considerations and ultrastructural findings. Am J Obstet Gynecol 1976;124:523-8.
Young RH, Prat J, Scully RE. Epidermoid cyst of the ovary. A report of three cases with comments on histogenesis. Am J Clin Pathol 1980;73:272-6.
Ozercan IH, Cobanoglu B, Simsek M, Dogan C, Ozercan MR. Epidermoid cyst of the ovary: A case report. Pathologica 2000;92:284-5.
Peters K, Gassel AM, Müller T, Dietl J. Ovarian epidermoid cyst and endometrioid carcinoma: Do they share their origin?. Zentralbl Gynakol 2002;124:443-5.
Hurwitz JL, Fenton A, McCluggage WG, McKenna S. Squamous cell carcinoma arising in a dermoid cyst of the ovary: A case series. BJOG 2007;114:1283-7.
[Figure 1], [Figure 2], [Figure 3]