Gastric carcinoma with osteoclast-like giant cells: a case report and review of the literature.

Gastric carcinoma with osteoclast-like giant cells (OGCs) is an extremely rare tumor. So far, only six cases have been reported in the literature. Here we report an additional case of this tumor in a Chinese 78-year-old man presented with abdominal pain, vomiting, and hematemesis. Physical examination and gastroscopy revealed a tumor in the gastric antrum. The biopsy and pathological findings indicated a gastric adenocarcinoma with OGCs, which were present in both the tumor and the metastatic lymph nodes. Further immunohistochemical staining indicated that OGCs were reactive with CD68, CD45, and vimentin protein, but not with pancytokeratin, carcinoembryonic antigen, or epithelial membrane antigen, suggesting the monocytic/histiocytic derivation of these OGCs. In situ hybridization for Epstein-Barr virus showed no nuclear positivity in either adenocarcinoma or OGCs. Postoperative follow-up showed that the patient had survived for at least 6 months without recurrence. Further investigation is warranted to clearly define the prognostic significance of OGCs in gastric carcinoma.