Introduction: Abdominal ultrasound is considered an initial examination of the the gastrointestinal tract. The case is presented in which ultrasound (US) detected a 'pseudokidney' sign that enabled the tentative diagnosis of a colonic neoplastic lesion. Case report: A 78-year-old patient was admitted to the Department of Internal Diseases due to weight loss and anaemia. US demonstrated abnormalities in the form of intestinal wall thickening with a hyperechoic centre. This finding led to the tentative diagnosis of a neoplastic lesion. After further diagnostic procedures, i.e. colonoscopy and histopathological examination of biopsy specimens, the patient was diagnosed with colon adenocarcinoma. Conclusions: In many cases, experienced US radiologists can initially assess the intestinal wall and other organs, which effectively directs towards further diagnostic management, hence accelerates the diagnosis and decision to apply a given therapeutic option or otherwise