This course includes an overview of important neoplastic and non-neoplastic diseases of the lymph nodes and bone marrow, emphasizing the need for a comprehensive multidisciplinary approach with careful clinicopathological correlation. Examples from the diagnostics of these diseases are used to understand the importance of interdisciplinary collaboration. Cases are divided into 4 groups - non-neoplastic (reactive) lymph node lesions, bone marrow pathology, B-cell lymphomas and T-cell lymphomas.