We report a case of primary colonic lymphoma incidentally diagnosed in a patient presenting a gallbladder attack making particular attention on the diagnostic findings at ultrasound(US) and total body computed tomography(CT) exams that allowed us to make the correct final diagnosis.A 85-year-old Caucasian male patient was referred to our department due to acute pain at the upper right quadrant,spreaded to the right shoulder blade.Patient had nausea and mild fever and Murphy’s maneuver was positive.At physical examination a large bulky mass was found in the right flank.Patient underwent to US exam that detected a big stone in the lumen of the gallbladder and in correspon-dence of the palpable mass,an extended concentric thickening of the colic wall.CT scan was performed and confirmed a widespread and concentric thickening of the wall of the ascending colon and cecum.In addition,revealed signs of microperforation of the colic wall.Numerous large lymphadenopathies were found in the abdominal,pelvic and thoracic cavity and there was a condition of splenomegaly,with some ischemic outcomes in the context of the spleen.No metastasis in the parenchimatous organs were found.These imaging findings suggest us the diagnosis of lymphoma.Patient underwent to surgery,and right hemicolectomy and cholecystectomy was performed.Histological examination confirmed our diagnosis,revealing a diffuse large B-cell lymphoma.The patient underwent to Cyclophosphamide,Hydroxydaunorubicin,Oncovin,Prednisone chemotherapy showing only a partial regression of the lymphadenopathies,being in advanced stage at the time of diagnosis. We report a case of primary colonic lymphoma incidentally diagnosed in a patient presenting a gallbladder attack trying particularly on the diagnostic findings at ultrasound (US) and total body computed tomography (CT) exams that allowed us to make the correct final diagnosis. A 85 -year-old Caucasian male patient was referred to our department due to acute pain at the upper right quadrant, spreaded to the right shoulder blade. Patient had nausea and mild fever and Murphy’s maneuver was positive. At physical examination a large bulky mass was found in the right flank.Patient underwent to US exam that detected a big stone in the lumen of the gallbladder and in correspondent deity of the palpable mass, an extended concentric thickening of the colic wall. CT scan was performed and confirmed a widespread and concentric thickening of the wall of the ascending colon and cecum.In addition, revealed signs of microperforation of the colic wall. Numerous large lymphadenopathies were found in the abdomi nal, pelvic and thoracic cavity and there was a condition of splenomegaly, with some ischemic outcomes in the context of the spleen. No metastasis in the parenchimatous organs were found. These imaging findings suggest us the diagnosis of lymphoma. Patient underwent to surgery, and right hemicolectomy and cholecystectomy was performed. Histological examination confirmed our diagnosis, revealing a diffuse large B-cell lymphoma. The patient underwent to Cyclophosphamide, Hydroxydaunorubicin, Oncovin, Prednisone chemotherapy showing only a partial regression of the lymphadenopathies, being in advanced stage at the time of diagnosis.