Gastric carcinoma with osteoblastic differentiation.

INTRODUCTION: Carcinosarcoma is a rare malignant biphasic tumor which has sarcomatous and carcinomatous components. Stomach localization is very rare. We discuss the diagnosis, follow-up and treatment of patients diagnosed with gastric carcinosarcoma in company with the literature review. PRESENTATION OF CASE: A 73-year-old white male patient applied to hospital with dyspeptic complaints lasting for 2months. His endoscopic examination revealed an ulcero-vegetating mass in the cardiac region of his stomach. Total gastrectomy and D2 lymph node dissection were performed for the patient. In the pathologic evaluation, the tumor was found consistent with Stage IIA stomach adenocarcinoma in accordance with AJCC (7edt, 2010) classification. Pathologic specimen was reevaluated by an expert pathologist for the patient with progression and liver metastasis under adjuvant chemotherapy and concomitant radiotherapy. The new pathology was consistent with gastric carcinosarcoma, and 90% of the tumor was identified as osteosarcoma whereas 10% was identified as carcinoma. Cisplatin doxorubicine-based chemotherapy was given considering the fact that sarcomatous component was dominant.(1) The patient was given 3 courses of chemotherapy. However, as the patient showed progression under therapy, he died after 14months of the diagnosis. DISCUSSION: Gastric carcinosarcoma is a very rare and clinically aggressive malignancy. Recurrence is likely to occur with a rate of more than 50% in patients who have undergone resection within the first year following surgery, and overall survival time is 10-15months.
CONCLUSION: In refractory gastric carcinoma cases with rapid progression, we suggest that gastric carcinosarcoma with biphasic component should be taken into consideration and the pathological evaluation should be performed by an expert pathologist.