Background: Malignant pericardial effusion is a rare entity in stomach cancer, since it has been reported in only six patients. Osteosclerotic bone metastasis are similarly unusual, with five patients described in the literature.
Case report: A 39-year-old man was referred to our department for dry cough and dyspnea. The chest radiography evidenced a remarkable enlargment of the cardiac profile and echocardiography revealed massive pericardial effusion. A diagnosis of cardiac tamponade was made and pericardiocentesis was performed. Cytological analysis of the pericardial fluid disclosed cells consistent with adenocarcinoma, suggesting a malignant effusion. The patient showed high serum levels of alkaline phosphatase and total body X-ray scan revealed diffuse osteosclerosis of the cervico-thoracic-lumbar spine, shoulders, proximal humerus and femurs. Bone marrow
biopsy was performed and evidenced metastatic adenocarcinoma with increased osteoblastic activity. A search for the primary site was done and esophagogastroduodenoscopy disclosed gastric cancer. The histological examination revealed poorly differentiated adenocarcinoma. Therefore, the final diagnosis was advanced gastric cancer with osteosclerotic bone
metastasis and pericarditis carcinomatosa with pericardial effusion.
Conclusions: Although the contemporary presence of both cardiac tamponade and diffuse osteosclerotic skeletal metastasis has not been previously reported in patients with gastric adenocarcinoma, stomach malignancies should be considered in differential diagnosis of malignant pericardial
effusion and/or osteosclerotic skeletal metastasis.

Keywords: Gastric adenocarcinoma, malignant pericardial effusion, osteosclerotic metastasis