**5. Ovarian mucinous carcinomas (OMCs)**

Primary ovarian mucinous tumours are relatively rare, approximately 10–15% of all ovarian tumours and most of them (80%) are benign or borderline mucinous tumours. Mucinous carcinomas in the ovary represent 3% of ovarian carcinomas with relatively high prevalence in women below 40 years of age [106] and most of them are of metastatic origin, particularly from the gastrointestinal or pancreatobiliary tract associated with pseudomyxoma peritonei [5, 107]. Primary OMCs originate mainly

*Recent Advances in Classification and Histopathological Diagnosis of Ovarian Epithelial… DOI: http://dx.doi.org/10.5772/intechopen.106545*

from mucinous benign or borderline tumours, with a small percentage originating from mature cystic teratomas or Brenner tumours with gastrointestinal pattern component [106, 107]. They are more commonly unilateral of large size (>13 cm) with no ovarian surface involvement. On the other hand, metastatic mucinous carcinomas are bilateral, smaller in size and associated with pseudomyxoma peritonei and imaging findings from other organs, mainly gastrointestinal or pancreatobiliary tract. They have a favourable prognosis in early clinical stages, albeit in advanced stages they show chemoresistance with unfavourable clinical outcomes [108, 109].
