A 56-year-old male patient who was on follow-up for rectosigmoid colon cancer revelaed a pelvic mass on abdominal CT. FDG-PET/CT performed for staging showed hypermetabolic mass consistent with recurrence and metastatic lymphadenopaties at the left inguinal, right external iliac and promontorial region. PET/CT also revealed metastatic lesion in the liver and multipl lesions at the bones as well as in the bone marrow (Fig. 3). Bone marrow biopsy was done with absolutely normal blood count directed by PET/CT findings. Bone marrow metastasis was found consistent with poorly differentiated mucinous adenocarcinoma secondary to colon cancer.