Metastatic Ewing's Sarcoma in Right Colon

Abstract

A 36-year-old man underwent chemoradiotherapy followed by surgery for Ewing’s sarcoma of paranasal sinuses. Post-treatment he recovered well. Two years later he presented with abdomen pain, vomiting, and melena. Contrast-enhanced computed tomography of abdomen showed mass lesion in right colon, involving cecum and ascending colon along with abdomen lymphadenopathy and ascites (►Fig. 1). Colonoscopy was performed that detected large ulceroproliferative growth with luminal narrowing in ascending colon, which could not negotiate scope further to visualize cecum (►Fig. 2). Endoscopically lesion was looking like adenocarcinoma; however, histopathology examination was suggestive of metastatic round cell tumor. In the background of Ewing’s tumor in the past, immunohistopathology examination was done and CD-99 and vimentin were found strongly positive (►Figs. 3 and 4) with high Ki-index (90%) suggestive of colonic Ewing’s sarcoma. Patient was managed with right hemicolectomy plus ileocecal anastomosis followed by chemotherapy. Ewing’s sarcoma is amalignant tumor that primarily involves bone and soft tissue. Among extraosseous tumors, the most common sites of disease are trunk, extremities, head and neck, and retroperitoneum. However, involvement of colon is rare.1 Management of Ewing’s sarcoma has evolved over the last few decades to the present treatment involving multiagent chemotherapy combined with surgery and/or radiotherapy. Combination chemotherapy has traditionally included vincristine, doxorubicin, cyclophosphamide, and dactinomycin.2 Our case