Spontaneous primary B cell lymphoblastic lymphoma of the spleen of a ۲۴-month-old male C۵۷BL/۶ mouse

Spontaneous lymphoid neoplasms are common among aged C۵۷BL/۶ mice, predominantly manifesting as T cell lymphomas. However, primary B cell lymphoblastic lymphomas are rare and poorly characterized, especially in laboratory animals. This case report describes a primary B cell lymphoblastic lymphoma in the spleen of a ۲۴-month-old male C۵۷BL/۶ mouse. Gross examination revealed an enlarged spleen with a homogenous, white, firm mass replacing the normal parenchyma. Histopathological analysis revealed that the splenic architecture was diffusely replaced by neoplastic lymphoid cells with high mitotic activity. Immunohistochemical staining confirmed the B cell origin of the neoplasm, demonstrating strong CD۲۰ positivity and CD۳ negativity. This case underscores the importance of detailed pathological evaluation in aged laboratory mice, especially to distinguish spontaneous lesions from treatment-induced effects in experimental studies. These findings contribute to the understanding of lymphoid neoplasms in laboratory animals, as well as provide valuable reference data for pre-clinical research in toxicology and oncology.

کلیدواژه ها:

B cell ، C۵۷BL/۶ ، Lymphoblastic lymphoma ، Mouse ، Spleen