Rare ovarian cancer which has metastasized from a primary site (usually from the GI tract).
- Primary sites: Stomach (M/C) > Colon, appendix and breast
- Accounts for 1-2% of all tumors of the ovary
- 80% cases are bilateral
- Metastatic disease with very poor prognosis (10% cases survive more than 2 years after diagnosis)
History:
In the year 1896 the German doctor Friedrich Krukenberg (1871-1946) presented 5 cases of peculiar ovarian tumor having appearance of malignant cells as new type of primary ovarian sarcomas which he named “fibrosarcoma ovarii mucocellulare (carcinomatodes)”. In his thesis he proposed it as a primary tumor of ovary, but latter it was proved to be nearly always secondary to gastrointestinal (GI) tract malignancy particularly stomach.
Many aspects of Krukenberg tumors still remain controversial, including the mechanism of metastases or even the pathologic tumor characteristics used for diagnosis. The current criteria used by the World Health Organisation was established in 1973 by Serov and Scully.
Clinical features
- Presenting symptoms are usually related to ovarian involvement (mainly because of the usually bilateral and often large ovarian masses):
- Abdominal pain
- Distension
- Nonspecific GI symptoms or asymptomatic presentations
- Virilization (from hormone production by ovarian stroma)
- Ascites (50% cases) and usually reveals malignant cells
Diagnosis
The diagnosis of the primary carcinoma can be made either preoperatively, during the operation for the ovarian metastasis, or within a few months postoperatively. Often, the primary tumor is too small to be detected.
Imaging:
Abdominopelvic sonography and computed tomographic scans
- Bilateral ovarian masses
Tissue biopsy:
- Signet ring cells with a bull’s eye or targetoid appearance containing a large vacuole with a central or paracentral droplet of mucin that appears as an eosinophilic body
- Arranged in tubules and cords
Differential diagnosis:
- Ovarian tumors with signet ring cells containing mucin:
- Primary mucinous carcinoma
- Mucinous carcinoid tumors
- Ovarian tumors with signet ring cells containing nonmucinous materials:
- Signet ring stromal tumor
- Sclerosing stromal cell tumor
- Clear cell adenocarcinoma of the ovary
Management
Treatment generally consists of surgery, chemotherapy or radiotherapy but guidelines concerning treatment of choice and appropriate timing of intervention have yet to be established.