CASE REPORT COLLISION TUMOUR: BILATERAL MUCINOUS ADENOCARCINOMACOEXISTING WITH DERMOID CYST IN AN OVARY: AN EXTREAMLYRARE CASE

Abstract

Collision tumour is defined as coexistence of two different tumours in the similar organ without
any histological intermixing. However, collision tumors have been reported in various organs
like esophagus, stomach, thyroid glandbut collision tumors arising from ovaries are extremely
rare entities [1,2]. Coexistence of tumors with different histologic combinations has been
reported in the literature for the ovary, such as serous papillary cystadenocarcinoma and
granulosa cell tumor, serous adenocarcinoma and steroid cell tumor, and teratoma with granulosa
cell tumor [3,4,5]. However, ovarian collision tumors are most commonly composed of teratoma
and cystedenoma or cystadenocarcinoma [6]. Benign mucinous cystadenomas account for 80%of mucinous ovarian tumors and 20-25% of overall benign ovarian tumors [7]. Dermoid cyst is a
type of germ cell tumor comprising well-differentiated tissues and three germ cell layers:
ectoderm, mesoderm, and endoderm, which is also known as mature cystic teratoma [8]. These
tumors are characterized as generally slow-growing and unilateral, with a reported bilateral
incidence of 10% [9]. Multiple dermoid cysts within a single ovary are rare. The juxtaposition
with dermoid cysts has been reported as comprising approximately 5% of benign mucinous
ovarian tumors and rare examples of proliferating mucinous tumors [10].
The case is here reported of a rare collision tumor consisting of mucinous adenocarcinoma with
dermoid cyst in same ovary.