Three cases of clear‐cell adenocarcinoma arising from endometrioma during hormonal treatments

Abstract

Endometrioma is known to be an occurrence site of ovarian cancer, but there is no evidence on how to reduce the risk of canceration. Here, we report three cases of ovarian cancer arising from endometrioma during hormone therapies of GnRH analogue and tamoxifen, low-dose estrogen-progestin (LEP) and dienogest. In all cases, each hormonal treatment was effective in shrinking the size of the endometrioma. During hormonal treatments, solid parts inside endometrioma were observed, which was followed by surgery. The histology of the solid parts was clear-cell adenocarcinoma in all cases. An immunohistochemistry study demonstrated that the estrogen receptor (ER) and progesterone receptor (PR) were positive in the endometriosis part but negative in the cancer part, while the human EGF receptor (HER) 2 was negative or very weak in the benign part and positive in the malignant part in all three cases. Even though hormonal treatments seem to be effective to regulate endometrioma, careful observation is needed to follow-up patients with endometrioma.

Significant risk factors for malignant transformation of ovarian endometrioma during dienogest treatment: a case report and retrospective study

“…Because two cases among the four cases of MT exhibited recurrences of OMA after LC and because the other two cases exhibited cyst size enlargement after starting DNGT, careful observation of the cyst size is important, regardless of the use of surgical treatment. However, similar to previous reports [11], in our hospital, we could not prevent the two cases of MT (Table 1, case 1 and case 2) by follow-up ultrasound examination at an interval of 6 months.…”

“…However, several adverse effects, including uterine bleeding, have been reported [10]. Among these side effects, some cases of malignant transformation (MT) during DNGT have been reported [11], although MT during DNGT is very rare. However, a detailed analysis of this risk factor has not been performed.…”