Struma ovarii: Clinical presentations of an uncommon tumor

IJCRI – International Journal of Case Reports and Images, Vol. 3 No. 4, Apri l 201 2. ISSN – [0976-31 98]

IJCRI 201 2;3(4):1 0–1 4.www.ijcasereportsandimages.com

Struma ovarii: Clinical presentations ofan uncommon tumorZied Khediri, Chaouki Mbarki, Anis Ben Abdelaziz,Najeh Hsayoui, Sana Mezghenni, Hedhili Oueslati

ABSTRACTIntroduction: Struma ovarii is a rare benigntumor which represents less than 3% of ovarianteratomas. Case Series: We report three cases ofdifferent clinical presentations of struma ovarii,to attempt to define the clinical features andcharacteristics of this tumor with respect toultrasonographic findings, histologicalcharacteristics and way of optimal management.Conclusion: We recommend that, without anyconfirmation of malignancy, conservativemanagement should be chosen and laparoscopicway should be preferred if possible.Keywords: Struma ovarii, Thyroid, Ovarianneoplasm

*********Khediri Z, Mbarki C, Abdelaziz AB, Hsayoui N,Mezghenni S, Oueslati H. Struma ovarii: clinicalpresentations of an uncommon tumor. InternationalJournal of Case Reports and Images 2012;3(4):10–14.

*********doi:10.5348/ijcri201204106CS3

INTRODUCTIONThyroid tissue is observed not uncommonly in5–15% of dermoid tumors. Struma ovarii is a teratomadefined by the presence of thyroid tissue in more than50% of the tumor [1]. Struma ovarii comprises 1–4% ofbenign ovarian teratoma [2–4].It is a benign condition, but occasionally malignanttransformation is observed in about 5% of cases.However, due to rarity of this type of tumor there hasbeen a paucity of data in the past literature pertaining todiagnosis and treatment of this tumor.We report three cases of different clinicalpresentations of struma ovarii, to attempt to define theclinical features and characteristics of this tumor withrespect to ultrasonographic findings, histologicalcharacteristics and way of optimal management.

CASE SERIESCase 1: A 17yearold, female, gravida 0, menarcheat 13, consulted for irregular menstruations. Her pastmedical history was not significant. Physicalexamination revealed a palpable mobile mass in theright lower abdomen. The patient was admitted forfurther investigations. Ultrasonography (USG) of thepelvis and abdomen revealed a large pelvic cyst, arisingfrom the right ovary, sized 16.3 cm in largest dimension,with heterogeneous echogenicity and septa. The uterusand left ovary were normal. The patient had no ascites.(Figure 1). The patient’s serum CA125 level was 11.85IU/ml (normal level <35 IU/ml), AFP was 1.41 µg/l(normal level <10 µg/L ), TSH was within normal range(3.02 IU/ml, normal level: 0.15–5 IU/ml). Routinebiochemistry was unremarkable. The patient underwenta laparoscopic surgery. The uterus was in normal size

CASE SERIES OPEN ACCESS

Zied Khediri1 , Chaouki Mbarki2, Anis Ben Abdelaziz1 ,Najeh Hsayoui1 , Sana Mezghenni3, Hedhil i Oueslati4

Affi l iations: 1Resident in gynecology & obstetrics,Department of gynecology & obstetrics, Hospital of BenArous, Tunisia; 2Assistant professor in gynecology &obstetrics, Department of gynecology & obstetrics,Hospital of Ben Arous, Tunisia; 3Professor in Radiology,Department of Radiology, Hospital of Ben Arous, Tunisia;4Professor in gynecology & obstetrics, Department ofgynecology & obstetrics, Hospital of Ben Arous, Tunisia.Corresponding Author: Chaouki Mbarki, MD, Yesminette,Ben Arous, Tunisia, Postal Code 2029; Ph: 0021 6 21 79 9563 Email : [email protected]

Received: 05 August 201 2Accepted: 1 9 December 201 2Published: 30 Apri l 201 2

Khediri et al. 1 0


IJCRI 201 2;3(4):1 0–1 4.www.ijcasereportsandimages.com Khediri et al. 11

and shape, as well as the left ovary. A 20x16 cm cyst,with regular limits had replaced the right ovary. Therewas no evidence of intraperitoneal spread of disease orretroperitoneal adenopathy. Laparoconversion wasnecessary and transparietal cystectomy was performed.The final pathology revealed right struma ovariicontaining exclusively benign thyroid tissue confined tothe ovary. Immunohistochemistry was not performed.The patient recovered uneventfully and was dischargedhome on the fifth postoperative day. Following up threemonths after her surgery, she had normal USG controland normal thyroid function tests and CA 125 levels.Case 2: A 31yearold woman was admitted to ourdepartment for evaluation and management of apersistent pelvic mass detected on a routine ultrasoundexamination. The patient had undergone laparoscopicexploration in 1998 for a two year infertilityinvestigation. She was gravida 0. The patient had noother notable past medical history. Clinical examinationwas normal, and no pelvic mass was palpable. Pelvicultrasound showed normal uterus and right ovary inaddition to a heterogeneous echogeneous mass of fivecm in the left adnexa. Magnetic resonance imagingfound a tissue mass of 5.4x5 cm in the left adnexa, well

delineated with a hypersignal in T1 and T2 and markedenhancement of the mass in Gadolinium enhanced T1weighted images (Figure 2). Laboratory data werenormal with a normal level of CA125 (5.38 IU/ml). Thepatient underwent laparoscopic intraperitonealcystectomy. Peroperative exploration showed a leftovarian mass, well delineated, with no septa orvegetations. Histopathologic examination showed astruma ovarii with benign thyroid cells.Immunohistochemistry was performed and showed thepresence of thyroglobulin (+) cells. Postoperative periodwas uneventful and patient was discharged home on thesecond postoperative day. Patient was well for threemonths with normal CA125 level. The patient waspregnant within a year.Case 3: A 45yearold, female was admitted forpersistent metrorrhagia, refractory to medical treatment(nomégestrol, 5 mg/day, for three months). The patientwas diabetic under oral treatment, and hadhypertension under monotherapy. She was gravida 4para 4, and had never had surgery. She were using IUDfor contraception. Clinical examination as well asroutine laboratory exams was normal. Cervix wasmacroscopically normal. Exploratory hysteroscopy after

Figure 1: Struma ovarii in ultrasonography. A) Large pelvic cyst, replacing the right ovary, sized 16.3 cm in largest dimension, withheterogeneous echogenicity and septa, B) Absence of doppler signal.

Figure 2: Struma ovarii in MRI. Tissue mass of 5.4x5 cm in in left adnexa, well delineated with a hypersignal in T1 and T2, andmarked enhancement of the mass in Gadolinium enhanced T1 weighted images. (AT1 weighted image, BT2 weighted image).


IJCRI 201 2;3(4):1 0–1 4.www.ijcasereportsandimages.com Khediri et al. 1 2

IUD removal was also normal. Pelvic ultrasound founda normal uterus with normalsized ovaries. No cysticmass was detected. The patient underwent vaginalhysterectomy with bilateral oophorectomy. Onperoperative macroscopic examination both ovaries aswell of the uterus were normal. Gross histopathologicexamination showed a normal endometrial aspect, aswell as a normal left ovary. However, surprisingly, theright ovarian cut surface was multicystic with cystsvarying from 1–2 cm in diameter filled with a brownjellylike gelatinous material. Microscopy showedbenign colloid filled thyroid follicles with no cytologicalfeature of malignancy and histology confirmed thediagnosis of struma ovarii of the right ovary (Figure 3).Immunohistochemistry was not performed. Postoperative followup was uneventful.

Figure 3: Pathologic Aspect of struma ovarii, A) Thyroid tissuein direct contact with the ovarian parenchyma, B) Thyroidfollicles at high magnification.

DISCUSSIONStruma ovarii comprises 1–4% of all dermoid tumorsof the ovary, and very rarely presents in a malignantform, occurring in 0.3%–5% of all struma ovarii tumors[2–4].The search of our database in the Hospital of BenArous starting from 2005 to date has found only threecases of struma ovarii among a total of 35 dermoidtumors. Therefore, the three struma ovarii patientsrepresented 8.57% of all dermoid patients, amongwhom none were diagnosed as malignant struma ovarii.These figures are quite different from previouslyreported data [2–4], particularly our high incidence ofstruma ovarii among all teratomas, which may beattributed to the rarity of struma ovarii and hence thevery low number of cases in previous literature.Struma ovarii usually presents after age of 40 yearsand the peak age of incidence is in the fifth decade [5].This tumor is present in only 17.6% of cases in patientsunder 30 years [6]. In our study, we have noticed a veryearly struma ovarii, discovered at the age of 17 years,and only one patient out of the three cases was above 40years of age. This seems in contradiction with the pastdata.Clinical symptoms previously reported due to thepresence of a struma ovarii are very diversed, such aslower abdominal pain, palpable lower abdominal mass,

abnormal vaginal bleeding, ascites, hydrothorax,elevated thyroid function and rarely thyroid tumors [7,8]. Previous reports have shown that up to 47,1% ofpatients with struma ovarii are without symptoms, orare accompanied by nonspecific symptoms that aresimilar to other ovarian tumors [6]. The results of thisgroup seem to be in agreement with the aboveobservation. In fact, in our cases, one patient out of thethree was symptomatic and consulted because of agrowing palpable mass of the lower abdomen. The twoother patients had no symptoms and the tumor wasdiscovered in one case by a routine USG and in theother case, the struma ovarii was a histologicaldiagnosis. It has been recommended in a previous studythat thyroid function tests have to be conducted in thepresence of symptoms and signs related to thyroiddysfunction [9]. The incidence of thyroid hyperfunctionhas been reported to be 5–8% of patients with strumaovarii [10]. In our three cases, there were no patientswith hyperthyroid symptoms and therefore, in only onepatient thyroid function tests were done. It cannot befully explained why there were no cases with thyroidhyperfunction within our group of patients especiallywith the two largesized tumors. CA125 is the mostimportant clinical marker for the diagnosis, treatmentand followup of epithelial ovarian cancer. Infrequently,benign struma ovarii is associated with elevated CA125levels [11]. In our cases, the two patients carrying largeovarian tumors have had pre and postoperative CA125 dosage, which have shown normal levels in bothcases. The third patient who has been diagnosed onlyafter histological exam, did not have any marker studiesdone, since the final pathology concluded to a benigntumor.Ultrasonography permits the diagnosis of theovarian masses, but orients to the diagnosis of strumaovarii in about 11.8% of cases only [6]. In our cases, weclearly saw the difference in USG between patients: Inone patient, USG was compatible with a benign ovariancyst, in the other the USG was suspicious withheteregenous echogenicity and presence of septa, and inthe third case the two ovaries were normal on USG. Instruma ovarii MRI typically shows a multilocular cysticmass with variable signal intensity within loculi. Someloculi show low intensity on T1 weighted images andvery low intensity on T2 weighted images,corresponding pathologically to gelatinous colloidmaterial [12]. Only one of our patients had MRI.Imaging findings in her case were not typical. Thus,struma ovarii does not have definite clinical or imagingcharacteristics that differentiate it from other ovariantumors, with the exception of hyperthyroid symptoms ifpresent.The final diagnosis of struma ovarii is based onpathology examination of the resected cyst/ovary, whichpermits at the same time, to confirm or excludemalignancy. Extensive grossing is required to rule outany other component before labeling it as monodermalteratoma. Struma ovarii typically consists of normalappearing thyroidal tissue composed of thyroid folliclesof various sizes and often is associated with mature


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cystic teratoma. Histologically, struma ovarii can alsoresemble thyroid adenoma of follicular, fetal, orembryonal type or thyroid carcinoma [13]. About 5% ofstruma ovarii are malignant [14]. Clinical features arequite similar, and malignancy should always besuspected, especially when the ovarian tumor isassociated to ascites, elevated CA125 levels, orsometimes a “pseudoMeigs” syndrome [2]. None of ourpatients had malignant struma ovarii.Therapy for benign struma ovarii is surgicalresection. The optimal way of management is, however,very controversial [15–16]. The very suspicious clinicalfeatures and peroperative findings of the tumor add tothis controversy. For women desiring furtherpregnancies, conservative management which consistsof a simple cystectomy or a unilateral oophorectomy,seems to be the optimal treatment [15, 16]. Althoughinfrequent, there have been reports of cases wherewomen have had successful pregnancies after suchconservative procedures in malignant struma ovarii[17]. In our cases, because of their young age, the twopatients with diagnosed ovarian tumors have hadsimple cystectomy, one by laparoscopy and the other bylaparotomy. One of the two patients has been pregnantin less than one year after surgery. We recommend that,if malignang is not confirmed, conservativemanagement should be chosen and if possible,laparoscopic method should be preferred.

CONCLUSIONLarger studies are needed to determine an optimaldiagnosis, management and followup protocols for thisrare ovarian tumor.

*********Author ContributionsZied Khediri – Substantial contributions to conceptionand design, acquisition of data, Drafting the article,revising it critically for important intellectual content,Final approval of the version to be publishedChaouki Mbarki – Substantial contributions toconception and design, acquisition of data, Drafting thearticle, revising it critically for important intellectualcontent, Final approval of the version to be publishedAnis Ben Abdelaziz – Substantial contributions toconception and design, acquisition of data, Drafting thearticle, revising it critically for important intellectualcontent, Final approval of the version to be publishedNajeh Hsayoui – Substantial contributions toconception and design, acquisition of data, Drafting thearticle, revising it critically for important intellectualcontent, Final approval of the version to be publishedSana Mezghenni – Substantial contributions toconception and design, acquisition of data, Drafting thearticle, revising it critically for important intellectualcontent, Final approval of the version to be publishedHedhili Oueslati – Substantial contributions toconception and design, acquisition of data, Drafting the

article, revising it critically for important intellectualcontent, Final approval of the version to be publishedGuarantorThe corresponding author is the guarantor ofsubmission.Conflict of InterestAuthors declare no conflict of interest.Copyright© Zied Khediri et al. 2012; This article is distributedunder the terms of Creative Commons attribution 3.0License which permits unrestricted use, distributionand reproduction in any means provided the originalauthors and original publisher are properly credited.(Please see www.ijcasereportsandimages.com/copyrightpolicy.php for more information.)

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13. Devaney K, Snyder R, Norris HJ,Tavassoli FA.Proliferative and histologically malignant strumaovarii: a clinicopathologic study of 54 cases. Int JGynecol Pathol 1993;12:333–43.14. Rosenblum NG, LiVolsi VA, Edmonds PR, MikutaJJ. Malignant struma ovarii. Gynecol Oncol1989;32:224–7.15. Hemli JM, Barakate MS, Appleberg M, DelbridgeLW. Papillary carcinoma of the thyroid arising instruma ovarii: report of a case and review ofmanagement guidelines. Gynecol Endocrinol2001;15:243–7.16. Berghella V, Ngadiman S, Rosenberg H, Hoda S,Zuna RE. Malignant struma ovariii. A case reportand review of the literature. Gynecol Obstet Invest1997;43:68–72.17. Ihalagama IR, Hewavisenthi SJ, Wijesinghe PS.Pregnancy following treated malignant strumaovarii. Ceylon Med J 2004;49:90–1.

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Struma ovarii: Clinical presentations of an uncommon tumor