A collisional lesion is a rare condition where two different tumors are located in the same area and collide with each other.[1][2] In one case, it was a collisional tumor in the left adrenal gland, composed of pheochromocytoma and diffuse large B-cell lymphoma.[1] In another case, a primary pulmonary collision tumor occurred in the right lobe of a 57-year-old woman, consisting of two benign tumors: a mixed squamous and glandular papilloma (MSGP) and a glomus tumor (GT).[2] The abnormality was revealed on chest CT and confirmed after right lower lobectomy with mediastinal lymph node dissection.[2] Histological examination showed two neoplastic components of different origin, which is the first such case reported in the lung.[2] CT images showed heterogeneous density of the lesion, suggesting different cellular components.[2] The diagnosis of collision tumors is difficult without characteristic clinical or imaging signs and depends on the pathology.[1][2] Treatment and prognosis depend on the biological behavior of individual histological types.[2]