Mucinous tumors are part of the surface epithelial-stromal tumor

Surface epithelial-stromal tumor

Surface epithelial-stromal tumors are a class of ovarian neoplasms that may be benign or malignant. Neoplasms in this group are thought to be derived from the ovarian surface epithelium or from ectopic endometrial or Fallopian tube tissue. This group of tumors accounts for the majority of all...

 group of ovarian neoplasm

Ovarian cancer

Ovarian cancer is a cancerous growth arising from the ovary. Symptoms are frequently very subtle early on and may include: bloating, pelvic pain, difficulty eating and frequent urination, and are easily confused with other illnesses....

s, and account for 12-15% of all ovarian tumor

Tumor

A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...

s.
Approximately 75% are benign

Benign

A benign tumor is a tumor that lacks the ability to metastasize. Common examples of benign tumors include moles and uterine fibroids.The term "benign" implies a mild and nonprogressive disease. Indeed, many kinds of benign tumors are harmless to human health...

, 10% are borderline

Borderline

Borderline or border line may refer to:*Border-In film:*Borderline , a film starring Paul Robeson*Borderline , a film noir starring Fred MacMurray*Borderline , a film starring Charles Bronson...

 and 15% are malignant

Malignant

Malignancy is the tendency of a medical condition, especially tumors, to become progressively worse and to potentially result in death. Malignancy in cancers is characterized by anaplasia, invasiveness, and metastasis...

.
Rarely, the tumor is seen bilaterally, approximately 5% of primary mucinous tumors are bilateral.

Benign mucinous tumors are typically multilocular (have several lobes), and the cysts have a smooth lining of epithelium

Epithelium

Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...

 that resembles endocervical

Cervix

The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina. It is cylindrical or conical in shape and protrudes through the upper anterior vaginal wall...

 epithelial cells with small numbers of gastrointestinal-type epithelial cells.
Borderline and malignant mucinous tumors often have papillae and solid areas.
There may also be hemorrhage and necrosis

Necrosis

Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...

.

It is well documented that malignancy may be only focally present in mucinous neoplasms of the ovary, so thorough sampling is imperative.

The major distinguishing features of mucinous tumors are that the tumors are filled with a mucus-like material, which gives them their name; this mucus is produced by mucus-secreting goblet cells very similar to the cells lining normal intestine.

These tumors may become very large, some have been weighed as large as 25 kilograms.

Cystadenocarcinomas (malignant tumors) contain a more solid growth pattern with the hallmarks of malignancy: cellular atypia

Atypia

Atypia is a clinical term for abnormality in a cell. The term is medical jargon for an atypical cell. Atypia: Etymology: Gk, a + typos, without type; a condition of being irregular or nonstandard....

 and stratification, loss of the normal architecture of the tissue, and necrosis. The appearance can look similar to colonic cancer.

Clear stromal invasion is used to differentiate borderline tumors from malignant tumors.

Pseudomyxoma peritonei

Pseudomyxoma peritonei

Pseudomyxoma Peritonei is an uncommon tumor known for its production of mucin in the abdominal cavity. If left untreated, mucin will eventually build up to the point where it compresses vital structures: the colon, the liver, kidneys,stomach, spleen, pancreas, etc.Unlike most cancers, this disease...

may present as a result of an ovarian mucinous tumor, however this is a rare cause of this condition, which is a rare condition. A more common cause of pseudomyxoma peritonei is a mucin-producing tumor of the appendix.

Since mucinous tumors arising from the ovary usually only involve one ovary, the presence of involvement in both ovaries with a mucinous tumor suggests that the tumor may have arisen in another location, and further study is warranted.

The risk of mucinous tumors is significantly associated with smoking: relative risk for current smokers 2.22 (2.22 times the risk for non-smokers) and 2.02 for past smokers. Risk is also associated with smoking duration: relative risk per 20 years was 1.44. See article by Tworoger SS in Cancer March 1, 2008 using data from the Nurses Health Study.

Prognosis

10-year survival rates for mucinous tumors is excellent in the absence of invasion.
In the case of borderline tumors confined to the ovary and malignant tumors without invasion, the survival rates are 90% or greater. In invasive mucinous cystadenocarcinomas, the survival is approximately 66%.