Endometrial signet ring cell metastasis from advanced gastric cancer: case report

Abstract

Background: Extrapelvic metastasis to uterus is extremely rare and the presence of signet ring cell (SRC) in uterine endometrium strongly raises the possibility of a metastasis from the breast, gastrointestinal tract, or elsewhere. Herein, we report a case of endometrial adenocarcinoma with SRC feature originated from stomach with rapid clinical deterioration. Case: A 38-year-old woman complained of dyspnea for a week and was referred to our institution for bilateral pleural effusion. We performed physical examinations, lab tests and imaging studies. And she had miliary lung nodules with effusion, disseminated osteoblastic bone lesions and endometrial hypermetabolic lesions in positron emission tomography (PET). CT-guided lung biopsy revealed adenocarcinoma of unknown primary, thus we performed mammography, gastroduodenoscopy, colonoscopy and gynecologic exams to find primary origin. We confirmed C-erbB2 negative poorly differentiated gastric adenocarcinoma in low body of greater curvature. But there were no abnormal intra-abominal lymph nodes or hepatic lesions in prior studies then we could not determine gastric cancer as a primary. Gynecologic exam showed focal endometrial hyperplasia so we decided to perform random endometrial biopsy. It revealed moderately differentiated adenocarcinoma with signet ring cell feature, which was identical to gastric biopsy specimen on slide review. Finally, we concluded that lung, bone and endometrial metastases were from stomach origin. After 2 cycles of stomach-directed palliative chemotherapy (FOLFOX, 5-FU/LV and oxaliplatin), treatment-refractory lymphangitic lung metastases progressed and lead her to respiratory failure (only 4 weeks after first treatment). Conclusion: Metastatic signet ring cell in endometrium from gastric origin is rare but clinicians should be aware that it usually indicates widespread disseminated disease at diagnosis and is associated with poor prognosis.