Acute pancreatitis due to pancreatic metastasis of osteosarcoma: a report of two cases

Metastasis of osteosarcoma to the pancreas is quite rare, and there have been no reports of metastasis-induced acute pancreatitis (MIAP) due to pancreatic metastasis of osteosarcoma. Here, we present two cases of MIAP due to pancreatic metastasis of osteosarcoma. Case 1: a 47-year-old woman was referred to our hospital due to osteosarcoma at left femur. She felt back pain 2 years postoperatively. An abdominal CT showed a 7 cm mass in the pancreatic head. Considering that the acute pancreatitis due to pancreatic metastasis, palliative radiotherapy was performed. Although abdominal pain was improved, she had died of multiple metastasis after 2 months. Case 2: a 42-year-old woman was referred to our hospital due to osteosarcoma at left femur. She felt abdominal and back pain 6 months after initial treatment. CT scans showed a large mass in the pancreatic tail. The mass increased rapidly over a short duration and complicated the acute pancreatitis. Palliative radiotherapy (30 Gy/10 fractions) was performed. After 1 month, the patient died of lung metastases. In previous reports, all patients with pancreatic metastases from osteosarcoma developed metastases at other sites, such as the lungs and bone. Therefore, we suggest that follow-up examinations at the abdominal lesion may be necessary for patients with metastatic disease.