Metastatic colorectal cancer presenting with bone marrow metastasis: a case series and review of literature.

With advances in treatment, patients with metastatic colorectal cancer (CRC) are now living longer with an apparent increase in the incidence of bone and bone marrow metastases (BMM). Common sites of metastatic disease from CRC include the liver and lungs with bone metastasis rarely occurring in the absence of visceral metastatic disease. We report a series of three patients presenting with isolated bone and BMM leading to a diagnosis of primary CRC. We have reviewed the literature regarding diagnosis, potential mechanisms leading to the development of osseous metastasis and outcome. A high level of clinical suspicion and in-depth understanding of the natural history of these rare metastases may guide future management and treatment decisions.