Neoplastic ascites in osteosarcoma: a case report.

BACKGROUND

Osteosarcoma is a malignant tumor of connective tissue whose tumor cells produce bone tissue. It can be classified as osteoblastic, chondroblastic, or fibroblastic, according to the predominant histologic type of cells. Its dissemination is hematogenous, and the lungs are the most frequent site of clinically evident metastasis. Extrapulmonary metastases are rare and more frequently diagnosed at necropsy. We present a case of osteosarcoma with peritoneal dissemination that developed neoplastic ascites.

CASE: A 46-year-old patient came to the hospital with a 4-month history of lumbar pain and weakness in the lower limbs. Computed tomography showed blastic lesions in the L3 vertebral body. Surgical resection and histologic analysis revealed a mixed osteoblastic and chondroblastic osteosarcoma. After only one session of chemotherapy, the patient presented a marked clinical worsening with extensive metastatic dissemination and occurrence of voluminous ascites. The cytologic examination of the ascitic fluid demonstrated frequent poorly differentiated tumor cells. The patient died a little more than 2 months after the diagnosis.

CONCLUSION

This case is the only report of osteosarcoma primarily focused on the vertebral column affected by peritoneal metastasis shown by cytologic examination of ascitic fluid.