Ovary is one of common sites of metastases.
Secondary ovarian tumors account for 5-15% of all malignant ovarian tumors.
Because imaging findings of primary ovarian tumors and secondary ovarian tumors overlap in many cases,
confident imaging distinction between the two may be challenging.
Therefore,
it is important to recognize the imaging characteristics of secondary ovarian tumors.
1.Metastases from stomach cancer(Krukenberg tumor)
Krukenberg tumor is metastatic adenocarcinomas to ovary,
most common from stomach that can contain mucin-secreting signet ring cells usually originating from gastrointestinal tract.
Imaging features(Fig.1 and 2) Krukenberg tumors are typically bilateral,
lobulated,
and predominantly solid tumor.
On T2 weighted MR images,
solid tumor components show heterogeneously low to high signal intensity.
Areas of decreased signal intensity are related to fibrous stroma and areas of increased signal intensity represent edema within connective tissue.
The mass shows variable enhancement in solid components.
2.Metastases from colon cancer
Colon cancer is one of most common tumors to involve the ovaries.
Colorectal cancer in women under 40 years of age has been reported to metastasize to the ovaries more frequently.
Imaging features(Fig.3 and 4) Bilateral,
either unilocular or multilocular predominantly cystic masses with a “stained glass appearance”,
associated with variable degrees of solid components,
show enhancement of septations and solid components within the predominantly cystic tumors.
On T2 weighted MR images,
masses show heterogeneously low to high signal intensity,
representing extensive necrosis.
3.Metastases from appendiceal cancer
Recent studies have demonstrated that most cases of pseudomyxoma peritonei are of appendiceal origin,
with the ovarian mucinous tumors resulting from secondary implantation by the appendiceal neoplasms.
Imaging features(Fig.5 and 6) CT scan and MR imaging show bilateral,
multilocular cystic ovarian tumors,
irregularly localized fluid within the peritoneal cavity,
mucinous tumor implantation on the peritoneum or omentum may also be present.
4.Metastases from breast cancer
Breast cancer patients have an increased risk of both primary and secondary ovarian neoplasm because of hereditary predisposition to breast and ovarian cancer due to BRCA1 and BRCA2 mutation.
Imaging features(Fig.7 and 8) The tumors are typically bilateral solid masses with a multinodular appearance,
occasionally containing cysts.
Metastatic pattern differs in accordance with histopathologic findings,
infiltrating lobular carcinoma more frequently involves ovaries.
5.Metastases from pancreatic cancer
Pancreatic adenocarcinoma that has metastasized to the ovaries is found in 4% to 6% of patients at autopsy but is rarely diagnosed clinically.
Many cases are misdiagnosed as primary ovarian mucinous carcinoma.
Imaging features(Fig.9 and 10) CT scan and MR imaging show multilocular cystic tumors,
which closely simulate primary ovarian mucinous cystic tumors.
In most patients,
there may also be metastases to other organs or extensive peritoneal dissemination.
6.Metastases from renal cell cancer
Metastatic ovarian tumor from renal cell cancer is vary rare,
there have been only 24 cases of ovarian metastases reported to date.
Imaging features(Fig.11) Predominantly cystic and focal solid mass with thick and irregular margin,
can contain cystic portion,
hemorrhage,
septation,
calcification,
enhancing component,
and can extracapsular spread.
7.Metastases from lung cancer
Lung cancer is a rare origin of metastases,
accounting for 0.3% of all metastatic ovarian tumors.
Most common presenting symptoms are abdominal pain,
distension.
Imaging features(Fig.12) CT scan and MR imaging show cystic and solid mass or predominantly solid mass such as Krukenberg tumor.
It has been reported that metastatic ovarian tumor from lung adenocarcinoma can show multinodular growth,
widespread necrosis,
and extensive lymphovascular invasion.
8.Metastases from lymphoma
Ovarian involvement by lymphoma usually occurs in wide-spread disease.
The majority of ovarian lymphomas represent non-Hodgkin lymphoma of B-cell lineage,
in particular,
diffuse large cell lymphoma and follicular lymphoma.
Imaging features(Fig.13 and 14) The masses are commonly bilateral,
predominantly solid tumors of diffusely intermediate signal intensity,
structures resembling septations of increased intensity on T2-weighted images.
The presence of enlarged LNs in locations which are atypical for lymphatic metastases from ovarian cancer,
hepatosplenomegaly are additional findings.