Krukenberg tumor

Template:Infobox medical condition (new) A Krukenberg tumor refers to a malignancy in the ovary that metastasized from a primary site, classically the gastrointestinal tract, although it can arise in other tissues such as the breast.<ref name=Ackerman04>Template:Cite book</ref> Gastric adenocarcinoma, especially at the pylorus, is the most common source.<ref name="Al-Agha2006">Template:Cite journal</ref> Krukenberg tumors are often (over 80%)<ref name="Al-Agha2006" /> found in both ovaries, consistent with its metastatic nature.<ref name="Al-Agha2006"/>

Signs and symptoms

Krukenberg tumors often come to the attention when they cause abdominal or pelvic pain, bloating, ascites, or pain during sexual intercourse. Krukenberg tumors can occasionally provoke a reaction of the ovarian stroma which leads to hormone production, that results in vaginal bleeding, a change in menstrual habits, or hirsutism,<ref name="Kiyokawa2006"/> or occasionally virilization<ref name="Papakonstantinou2011">Template:Cite journal</ref> as a main symptom. In rare cases the disease can manifest with hydronephrosis and hydroureter.<ref>Template:Cite journal</ref>

All these symptoms are non-specific and can also arise with a range of problems other than cancer, and a diagnosis can only be made following confirmatory investigations such as computed tomography (CT) scans, laparotomy and/or a biopsy of the ovary.

Cause and incidence

Krukenberg tumors can be seen in all age groups, with an average age of 45 years.<ref name="Al-Agha2006"/> In most countries, cancer that has metastasized to the ovary accounts for only about 1 to 2% of ovarian cancer;<ref name="Al-Agha2006"/> in the remainder, the ovary itself is the primary cancer site. However, in Japan they represent a much higher percentage of malignancies in the ovary (almost 20%) due to the increased prevalence of gastric cancer.<ref name="Al-Agha2006"/>

Krukenberg tumors account for about 15% of metastatic cancers that initially appear to have arisen in the ovary, and as such is less common than metastasis arising from ovarian epithelial and germ-cell tumors.Template:Citation needed

In people who have had nongynecologic malignancy, approximately 20% of adnexal masses are malignant, and 60% of these are Krukenberg tumors.<ref name="Juretzka2006">Template:Cite journal</ref>

Pathogenesis

There has been debate over the exact mechanism of metastasis of the tumor cells from the stomach, appendix or colon to the ovaries. Classically it was thought that direct seeding across the abdominal cavity accounted for the spread of this tumor, but spread by way of the lymphatic is considered more likely.<ref name="Al-Agha2006"/> Retrograde lymphatics are thought to be more important in the pathogenesis of Krukenberg tumour, since the ovaries in Krukenberg tumour do not show capsular invasion or a breach of the epithelium lining the surface. The average age of diagnosis of Krukenberg tumors may partly relate to the relatively increased vascularity of the ovaries.<ref name="Young2006"/>

Microscopically, Krukenberg tumors are often characterized by mucin-secreting signet-ring cells in the tissue of the ovary;<ref name="Young2006"/> when the primary tumor is discovered, the same signet-ring cells are typically found. However, other microscopic features can predominate.<ref name="Young2006"/><ref name="Kiyokawa2006">Template:Cite journal</ref> Krukenberg tumors are most commonly metastases from gastric cancer, particularly adenocarcinoma, or breast cancer<ref name=Ackerman04/> particularly invasive lobular breast carcinoma,<ref name="Al-Agha2006"/> but they can arise in the appendix, colon, small intestine, rectum, gallbladder, and urinary bladder<ref name="Kiyokawa2006"/> or gallbladder, biliary tract, pancreas, ampulla of Vater or uterine cervix.<ref name="Al-Agha2006"/>

Immunohistochemistry may help in diagnosing Krukenberg tumors from primary ovarian neoplasms<ref name="Young2006"/> but needs to be applied with discretion.<ref name="Young2007">Template:Cite journal</ref> For example, tumors that are immunoreactive to CEA or cytokeratin 20 (CK20) and negative for cytokeratin 7 (CK7) may be more likely to be of colorectal origin.<ref name="Al-Agha2006"/>

Treatment and prognosis

Since Krukenberg tumors are secondary (metastatic), management might logically be driven by identifying and treating the primary cancer. The optimal treatment of Krukenberg tumors is unclear.<ref name="Al-Agha2006"/> The role of surgical resection has not been adequately addressed<ref name="Al-Agha2006"/> but if metastasis is limited to the ovaries, surgery may improve survival.<ref name="Al-Agha2006"/><ref name="Cheong2004">Template:Cite journal</ref><ref name="Kim2010">Template:Cite journal</ref> The role of chemotherapy and/or radiotherapy is uncertain<ref name="Al-Agha2006"/> but may sometimes be beneficial.<ref name="Kim2010"/>

History

Krukenberg tumors are named after Friedrich Ernst Krukenberg (1871–1946),<ref>Template:WhoNamedIt</ref> who reported what he thought was a new type of primary ovarian malignancy in 1896; six years later these were shown to be of metastatic gastrointestinal tract origin.<ref name="Young2006">Template:Cite journal</ref> However, Paget had described the process in 1854.<ref name="Young2006"/>

External links

• Template:Chorus