Krukenberg tumor was described as a fibromatous mucin producing tumor in 1896 from F. Krukenberg. Later, it was well established that an neoplasm composed of signet-ring cell carcinoma and diffuse stromal proliferation. Krukenberg tumors generally rare tumors in western countries and accounts for 3-4 % metastatic ovarian tumors
2. However, the incidence of Krukenberg tumor in Japan rather high because of the high incidence of gastric cancer and accounts for 29 % of metastatic ovarian cancers
3,4. The primary tumor is frequently stomach in Krukenberg tumors. The rate of stomach as the primary site of Krukenberg tumor range from 70 % and 94 %
3-5. Tulunay et al
9 reported that the rate of stomach as the primary site of Krukenberg was % 63 in Turkey. Although, in some cases, a primary tumor couldn’t find for all imaging techniques and endoscopic tests.
In our case, the primary site of Krukenberg tumor was detected intramucosal EGC with endoscopic biopsies before gastric surgery. Tumor was shown intramucosal signet-ring cell carcinoma. Lymphatic invasion and vacular invasion was detected the endoscopic biopsy specimens. But we didn’t find any tumoral area at the serial examinations from total gastrectomy material. The cause of this situation could have removed intramucosal primary tumor during two endoscopic examination with biopsies. It is another probability that we couldn’t have find to the primary tumor area because the primary tumor to very smaller size after endoscopic biopsy working. Young ve Scully 6 emphasized, it can be the existence of very small primary gastric tumors with Krukenberg tumor and they reported that one case needed the examination of 200 blocks to detect the primary gastric tumor. We didn’t further pathologic examination because we detected the metastasis in the prepyloric one lymph node.
Krukenberg tumors are more common in premenopausal women than in postmenopausal women and the average age at diagnosis is to be 40 to 50 years 4,5,10. Krukenberg tumors are usually bilateral and unilateral tumors are very rare. In our case, Krukenberg tumor was unilateral localization in the left ovary. In the Krukenberg tumors, the metastasis from stomach to the ovaries can be three possible route: peritoneal spread, lymphatic metastasis, and hematogenous metastasis 11. For EGCs, peritoneal spread to the ovary with seeding is unlikely because the tumor is completely confined to the gastric wall. So, there can be the most possible spread route is via local lymphatic metastasis. The incidence and extent of lymph node metastasis from EGC is closely related to the depth of tumor invasion 12. The incidence of metastasis to regional gastric nodes from submucosal cancers are seen 20 % while only 3 % or less metastasize from mucosal cancers 13. In addition to, gastric mucosa is markedly decreased in the patients of severe atrophic gastritis. So, lymphatic capillaries may be found very near the surface epithelium. In our case we find diffuse atrophic gastritis and cancer cells may have enter the lymphatic capillaries from atropic mucosal surface 14.
We experienced a rare case of unilateral Krukenberg tumor derived from gastric mucosal carcinoma. The intramucosal primary lesion was demonstrated with endoscopic examination but it was not find in operation specimens although two serial seciton examination, and regional gastric lymph node metastasis was shown. In our case suggested that Krukenberg tumors may be derivated early gastric cancers and endoscopic investigation of the stomach should be carefully done. In addition there should be removed a lot of endoscopic biopsies.