Signet ring cell carcinoma of the breast as a source of pelvic floor metastatic mass. A case report.

Primary signet ring cell carcinoma of the breast is a very rare tumour. We present a case with pure signet ring cell carcinoma of the breast, which was recognized as metastasis on the pelvic floor, before developing breast symptoms and signs. A 40-year old woman was admitted with abdominal pain. First diagnostic effort revealed a cystic mass on the pelvic floor, compressing the colon and other neighbouring organs. A biopsy of the pelvic mass was performed. The histopathological examination revealed metastatic signet-ring cell carcinoma. At the time of the first operation, the mammary glands were not suspicious. No other sources of primary tumour were evidenced. An inflammatory sign developed in right breast two months after biopsy of the pelvic metastasis. The histopathology of the breast incisional biopsy revealed primary pure signet ring cell carcinoma of the breast. Because the oestrogen and progesterone receptor were negative in the tumoral tissue, the patient underwent chemotherapy followed by modified radical mastectomy, chemotherapy, and palliative resection of the metastatic mass. The patient was followed up for eight months. To our knowledge, in English literature, we believe that this case is the first report of signet ring cell carcinoma of the breast presenting with pelvic floor metastasis without breast sign.