Mantle Cell Lymphoma (MCL) is an uncommon and aggressive form of non-Hodgkin lymphoma (NHL) that develops from B cells, a type of white blood cell. It accounts for around 6% of all NHL cases. MCL is defined by aberrant proliferation of mature B lymphocytes, which primarily affects the mantle zone of lymph nodes. One distinct hallmark of MCL is the overexpression of cyclin D1, a cell cycle regulator. This overexpression is often induced by a chromosomal translocation between chromosomes 11 and 14, which results in the fusion of the cyclin D1 and immunoglobulin heavy chain genes. This genetic abnormality contributes to unregulated cell division and the aggressive nature of MCL. Mantle Cell Lymphoma is more common in older persons, with a median age of diagnosis of 60 years. It is frequently associated with painless lymphadenopathy, splenomegaly, and bone marrow involvement. MCL can also affect extranodal organs such as the gastrointestinal tract, liver, and spleen. Despite its aggressive nature, MCL has a variable clinical course, with some cases being more indolent and others progressing quickly. MCL is diagnosed using a combination of clinical evaluation, imaging investigations, and pathological study of lymph node biopsies. Immunohistochemistry and molecular analysis are critical for validating the existence of cyclin D1 overexpression and making a diagnosis. Treatment for MCL varies depending on the severity of the disease and the patient's overall condition. Chemotherapy, immunotherapy, and stem cell transplantation are among the standard treatment choices. Newer targeted medicines, such as B-cell receptor inhibitors and medications that target specific biological pathways, have showed promise in improving MCL patient outcomes. MCL has a poor prognosis due to its aggressive character, and the disease frequently recurs despite initial treatment responses. However, continuing research and clinical trials aim to produce more effective medicines and improve long-term results for people with Mantle Cell Lymphoma. Early identification and a multidisciplinary approach to care remain critical in dealing with this difficult hematologic malignancy.