Colonic Pseudolipomatosis: A Rare but Characteristic Endoscopic Condition.

BACKGROUND Colonic pseudolipomatosis (CP) can pose a diagnostic challenge due to its rare incidence and multiple presentations, most of them not very familiar to the endoscopist. Its etiology and pathogenesis have not been completely clarified. It can be related to mucosal iatrogenic injury caused during endoscopic examination or to chemical injury caused by residual disinfectants on the surface of the scope after cleansing. Imaging tests such as CT or MRI do not contribute to the diagnosis, but this condition has characteristic features that must be differentiated from pre-malignant lesions, like lateral-spreading tumors, in order to avoid further investigation and unnecessary treatment, such as endoscopic mucosal resection. CASE REPORT We report a case of a 65-year-old man who underwent to a screening colonoscopy due to his strong family history of colorectal cancer. Confluent whitish laterally-spreading lesions with a round pit-pattern in white-light HD scope were identified in the cecum and ascending colon. The lesion was biopsied with a cold forceps. Histopathologic analysis revealed multiples cysts filled with gas within the mucosal layer, associated with a mild inflammatory process, mainly composed of mononuclear cells and eosinophils. No giant multinuclear cells were identified. Moreover, although there was a mild inflammatory process in the epithelium, the architectural organization and tissue maturation were preserved with no nuclear atypia, consistent with a diagnosis of colonic pseudolipomatosis. CONCLUSIONS Colonic pseudolipomatosis is a rare, benign condition that must be not mistaken for more serious conditions, as CP requires no further investigation or treatment. In this setting, proper diagnosis is key to avoid unnecessary procedures.