[Primary Hodgkin's lymphoma of the colon]

Primary Hodgkin's lymphoma of the colon is exceedingly rare. We report on the case of a 74-year-old female patient presenting with weight loss and hematochezia. Proctocolonoscopy revealed a bleeding tumor localized in the right colonic flexure. Histological examination of initial mucosal biopsies could not verify malignancy; however, explorative surgery was decided in an interdisciplinary conference setting and right-sided hemicolectomy was performed. Macroscopically, a tumor measuring 5.5 cm in maximum diameter was found. By means of histology and immunohistochemistry the diagnosis of classic Hodgkin's lymphoma was made. Mesenteric lymph nodes were not affected and postoperative staging revealed no systemic spread. Therefore, the tumor fulfilled the criteria of a primary colonic Hodgkin's lymphoma. Diagnosis of primary colonic lymphoma can be difficult as clinical symptoms are typically unspecific and, as shown in this case, even primary biopsy histology can be falsely negative.