Signet-ring cell carcinoma of unknown primary location. Metastatic to lower back musculature - remission following FU/FA chemotherapy.

The detection of gastrointestinal signet-ring cell carcinoma by endoscopy can be a diagnostic challenge. The main clinical features include atypical metastasis and a poor prognosis. We present a case of a metastasizing signet-ring cell carcinoma with unknown primary location arising in 71-year-old female. Following 6 cycles of a routine intravenous FU/FA chemotherapy, an almost complete remission could be observed. After 2 years of follow up, metastatic recurrence was detected to the lower back musculature. This case report emphasizes the difficulties in diagnosing signet-ring cell carcinoma by endoscopy and demonstrates an unusual clinical course.