Abstract
A 57-year-old male with low back pain and hyperphosphatasemia was diagnosed as disseminated carcinomatosis of the bone marrow (DCBM) originating from cancer of unknown primary. Although an iliac bone marrow biopsy showed cancer metastasis, gastrointestinal endoscopy, imaging studies, tumor markers tests, and immunohistochemistry of the biopsy material failed to identify the primary tumor. Five courses of carboplatin and paclitaxel (CBDCA/PTX) therapy and two courses of gemcitabine (GEM) therapy were performed for cancer of unknown primary, but there was no therapeutic effect, and the patient died after the treatment during about 7 months. Autopsy revealed signet-ring cell carcinoma of the stomach, which was an early cancer limited to the small part of the antrum. Tumor size was 5 millimeters, the depth of submucosal invasion was about 500 micrometers, and neither vascular nor lymphatic infiltration was found. Reportedly, the most common primary tumor of DCBM is gastric cancer, most of which are advanced cancers. However, as in the present case, early cancer could be the cause. Besides, DCBM is known to develop long after surgery. Thus, the gastric cancer patients, especially when histological subtype is poorly differentiated adenocarcinoma or signet-ring cell carcinoma, should be followed up with reference to serum ALP and FDP, considering the rare occurrence of DCBM.
