Spontaneous Lymphoma in a SMP30 Knock-Out C57BL/6 Mouse

70-weeks-old female C57BL6 senescence marker protein 30 knock out mice exhibited anorexia, lethargy and enlarged abdomen because of an intraperitoneal mass. On necropsy, the mouse revealed a large brown-whitish mass located on the mesentery. The mass also exhibited systemic metastasis and spread over in various organs. On microscopic findings, the neoplastic masses were mainly composed of neoplastic round cells characterized by severe anisokaryosis, narrow cytoplasm, round nuclei, prominent nucleoli, and numerous mitotic figures (13-15 in a 400X field). Consequently, the present case was diagnosed as a metastatic lymphoma arising from a mesenteric lymph node, the tumor spread to other organs such as the intestine, kidney and thoracic cavity. According to previous studies, SMP30 plays an important role in inhibiting cancer in both human and mouse. Taken together, it seems that the present case can be used as a valuable asset for evaluating the potential risks of SMP30 depletion in developing lymphoma.