Malignant transformation in mature cystic teratoma of the ovary: a retrospective study of eight cases and review of literature

Abstract

IntroductionMature cystic teratoma (MCT) is the most common type of ovarian germ cell neoplasm, but occasionally it may undergo malignant change in any one of its elements. In this study, these rarely encountered tumors, occurring over a period of 25 years, were studied.Material and methodsA retrospective, tertiary hospital-based study was carried out in all histopathologically diagnosed cases of MCT (230) of the ovary from January 1990 to December 2014. The clinicopathological features of malignant transformation (MT) in MCT of the ovary were retrieved from the archives of the Department of Pathology and were analyzed.ResultsTwo hundred thirty (230) mature cystic teratomas of the ovary were found. MT was noted in eight of these cases, i.e. 3.5% of all the MCT. The mean age of the patients with MCT was 32.5 ±13.11 while the mean age of the patients with malignant transformation in MCT was 44.2 ±8.94 years. Grossly the mean size of the malignant teratoma was 11.7 ±2.7 cm, whereas it was 7.6 ±2.1 cm for mature cystic teratoma. Squamous cell carcinoma (SCC) was the most frequent MT seen in four out of eight cases, while one case showed an adenocarcinoma and the other a malignant melanoma, and two cases had transitional cell carcinoma.ConclusionsThe rate of malignant transformation in MCT increases with age and is much higher in the postmenopausal age group. Moreover, although SCC is still the commonest, transitional cell carcinoma (TCC) may also develop not infrequently as malignancy apart from other rare differentiations such as adenocarcinoma or malignant melanoma in an MCT.

Rare Case of Sarcomatoid Squamous Cell Carcinoma Arising in an Ovarian Mature Teratoma

“…In women under 30 years of age, MCTs are the most common ovarian germ-cell tumors. 17 Malignant transformation in MCTs usually occurs later in life, and is reported around the fifth decade. 3 Cases of SCCs arising in an MCT are uncommon, with an incidence lower than 2%, 10 but they are the most common malignancy to arise in MCTs, comprising $ 80% of malignancies.…”

“…3 Cases of SCCs arising in an MCT are uncommon, with an incidence lower than 2%, 10 but they are the most common malignancy to arise in MCTs, comprising $ 80% of malignancies. 17 Moreover, the clinicopathological characteristics, the treatment, the prognostic factors, and the mechanism of MT have not yet been well understood due to the rarity of such tumors, especially in women of reproductive age. 13 Malignant transformation may develop due to the long-term presence of a non-removed MCT.…”

“…18 Though the reason for this is not clear, it is postulated by some authors that the long-term presence of an MCT and squamous metaplasia of the columnar epithelium may be followed by such a malignant change. 17 The involvement of the human papillomavirus (HPV) has been suggested, but it must be further investigated. 13 Clinically, the tumor is usually asymptomatic, and is discovered accidentally during gynecologic investigations.…”

“…6 Increased tumor size has been associated with a higher progression to MT in MCTs, and a worse prognosis due to the more aggressive disease. 17 Rupture is an unusual complication of malignant MCTs, occurring in $ 1% to 2% of patients with SCCs in MCTs. 19 Moreover, in these patients, the preoperative radiological findings may not differ much from those observed in cases of uncomplicated MCT.…”

Chemical peritonitis resulting from spontaneous rupture of a mature ovarian cystic teratoma: a case report

“…Sometimes ipsilateral multiple ovarian teratomas can occur (with the incidence of about 9%) (9). Ruchi Rathore et al reviewed different studies and revealed that pathology side in unilateral cases may vary depending on studies (19).…”