Colorectal cancer with first known case of simultaneous bilateral tibial metastases.

The most common osseous metastatic regions for colorectal cancer are the lumbar and sacral vertebrae and the pelvis. There are few reported cases of isolated solitary tibial metastasis, and simultaneous bilateral solitary tibial metastases in colorectal cancer are even rarer. A 62-year-old female patient was admitted to our inpatient clinic 3 years after receiving initial chemotherapy for a rectosigmoid adenocarcinoma with liver metastasis. The patient complained of left leg pain. Radiographs and magnetic resonance imaging revealed a 3- × 3-cm mass in the right proximal tibia and a 2- × 7-cm mass in the middle third of the left tibia; both were highly suggestive of bone metastases. Bilateral tibial metastases were confirmed after tumor excision and prophylactic open reduction and internal fixation. The postoperative course was relatively uneventful. Colorectal cancer with bone metastases is uncommon, and most metastases are found at a single site in an extremity. We believe this is the first published case of simultaneous bilateral tibial metastases in a patient with colorectal cancer.