Epithelial Malignancies Arising in Ovarian Mature Cystic Teratoma: A Series, of 26 Cases

Abstract

Objective: To report a series of epithelial malignancies arising within ovarian teratomas along with clinical followup. Some previously unreported combinations of malignant component with MCT are also being reported. Material and Methods: Clinico-pathological details and clinical follow up of twenty six cases reported during January 2000 to March 2014 in the Section of Histopathology, of a tertiary care hospital of Pakistan are included. Results: Total 1418 cases of MCTs were reported, 26 (1.8%) of them showed epithelial malignancies. The mean age at presentation was 42.5 years (range; 15-70 years). Commonest clinical presentation was with abdominal pain and mass. All the patients underwent surgery as first line treatment. Malignant transformation in form of Squamous cell carcinoma was seen in 20 cases. In one case, in addition to squamous cell carcinoma, atypical proliferative serous tumor and high grade sarcomatous component was also present. Adenosquamous carcinoma, Poorly differentiated carcinoma, Endometrioid adenocarcinoma and Adenocarcinoma with mucinous differentiation represented malignant components in additional 4 cases respectively. Cases demonstrating endometrioid features and atypical proliferative serous tumor represent collision tumors. Two of the cases had papillary carcinoma (follicular variant) of thyroid arising within monodermal teratoma (struma ovarii). Clinical follow up was available in 13 cases and it is noted that patients with squamous cell carcinoma had a worse outcome. Conclusions: Malignancy occurring in a MCT is an extremely rare occurrence. It is very challenging to diagnose this malignant transformation clinically.