[Ovarian clear cell carcinoma derived from endometriotic cyst: a clinicopathological analysis of 54 cases]

To clarify the clinicopathological features of ovarian clear cell carcinoma derived from endometriotic cyst (EC-OCCC).

Totally 54 cases of EC-OCCC were recruited in the current retrospective study. The relation between ages, clinical symptoms and signs, surgical and pathological stages, serum CA125, findings of ultrasound, treatments and the sites of tumors, macro- and micro-features and expression of immunostainings were analyzed.

(1) Clinical features: the ages of patients were (50±6) years old (range 31-62 years old). Pelvic mass was the major complaint of 50 patients (93% , 50/54). Forty-five cases belonged to International federation of Gynecology and Obstetrics (FIGO) stage I, 4 cases were stage II and another 5 cases were stage III. Serum CA125 was elevated in 21 cases (54%, 21/39) before therapy. Doppler ultrasound showed 46 cases (85%, 46/54) had solid masses in pelvis. (2) Pathological findings: 52 cases (96%, 52/54) had their tumor unilaterally, and 2 cases (4%, 2/54) occurred bilaterally. The maximal diameters of endometriotic cyst (EC) ranged from 1.5 to 23.0 cm and maximal diameters of ovarian clear cell carcinoma (OCCC) components were from 0.5 to 12.0 cm. Fifty-one cases (94%, 51/54) had their tumor within EC, which showed focally irregular protrudings, grey-white papillae or solid nodules attached to the cyst wall. Three cases (6%, 3/54) appeared as irregular thickened wall of the cysts, ranged from 1.5 to 6.0 cm in the maximal length, with the microscopic features of EC and OCCC and the transitional areas between the 2 morphologies. All cases expressed cytokeratin (CK) 7 and pan-CK AE1/AE3, 17 cases (33%, 17/51) expressed ER and 5 cases (10%, 5/51) expressed PR. TP53 showed mutational phenotype in 19 cases (36%, 19/53). Sixteen cases (30%, 16/54) combined with uterine adenomyosis and 25 cases (46%, 25/54) with endometriosis at other sites. (3) Survival survey: during the period of 39.1 months follow-up, 3 cases relapsed and 2 cases died. (4) There was a significant difference of serum CA125 between patients of early-and advanced-stages (P=0.049). There were no differences identified in ages, diameters of EC and OCCC, the expression level of ER, PR and TP53, the co-existence of adenomyosis and endometrosis, as well as ultrasonic findings (P>0.05).

EC-OCCC could be recognized in early stage by symptoms and ultrasound due to accompanied endometriotic cysts, resulting in relatively good prognosis.