[A case of adenocarcinoma of unknown primary site successfully treated with gemcitabine monotherapy]

A 68-year-old female diagnosed with adenocarcinoma of unknown primary site (ACUP) by biopsy of supraclavicular lymph node was admitted to our department because of progressive dyspnea with cough. The diagnosis of multiple lung metastases and malignant pleural effusion was made. Marked elevation of serum CA 19-9 and DUPAN-2 urged us to treat her as a case of pancreatic carcinoma. Gemcitabine monotherapy yielded resolution of symptoms, decline in the level of tumor markers, shrinkage of lung metastases, and disappearance of pleural effusion. After 10 cycles, the chemotherapy was terminated. However, clinical deterioration was observed two months later. The re-treatment with gemcitabine was started, and a good response was obtained again. Gemcitabine monotherapy can be one of the treatment options for ACUP.