Granulocytic sarcoma (chloroma) presenting as colo-colic intussusception in a 16-year-old boy: an unusual presentation.

A 16-year-old boy presented with intestinal obstruction with left lumbar mass. On evaluation with ultrasonography and contrast-enhanced CT of abdomen he was found to have left colo-colic intussusception. On exploratory laparotomy he was found to have invagination of necrosed distal transverse colon and splenic flexure with omentum into descending colon with enlarged mesenteric lymph nodes for which left hemicolectomy was performed. Histopathology and immunohistochemistry was suggestive of submucosal infiltration by immature myeloid precursors with few metamyelocytes and occasional eosinophils and the cells showed cytoplasmic granular positivity with myeloperoxidase stain suggestive of granulocytic sarcoma (chloroma-extra-medullary manifestation of acute myeloid leukaemia). Our patient received three cycles of cytarabine+daunorubicin chemotherapy in the postoperative period and is doing well at 12 months of follow-up. Granulocytic sarcoma (chloroma) presenting as colo-colic intussusception is very rare and has not been reported in literature so far.