Case of a lung collision tumor consisting of squamous cell carcinoma of the lung and diffuse large B-cell lymphoma

Abstract

Background The collision tumor consisted of two malignant tumors that independently developed and were contiguous or had invaded each other. Among the reports of malignant collision tumors, collision tumors consisting of lung cancer and malignant lymphoma are extremely rare. We report case of a lung collision tumor consisting of squamous cell carcinoma of the lung and diffuse large B-cell lymphoma.Case presentationA 74-year-old man was admitted to the hospital due to identification of an abnormal nodular shadow in the right upper lobe on chest computed tomography following a chest X-ray. At the time of admission, a swollen lymph node of 7 cm × 5 cm was palpated in the left neck, and serum examination showed an abnormally high level of soluble interleukin-2 receptor. Close examination led to a diagnosis of stage IA squamous cell carcinoma of the lung and stage IVA malignant lymphoma, and treatment for the malignant lymphoma was prioritized. However, due to progression of lung cancer, a right upper lobectomy with lymph node dissection was performed. Pathological findings showed that squamous cell carcinoma and malignant lymphoma were both present in the same lesion.ConclusionOnly two cases of collision tumors consisting of malignant lymphoma and primary lung cancer were reported [1] [2] and this case is considered to be the third rare case in the world. As the rate of complications with other malignancies in patients with diffuse large B-cell lymphoma is high, in the case of advanced stage malignant lymphoma, physicians must consider which treatment should be prioritized according to the degree of progression of coexisting solid tumors.