Both hemophagocytic lymphohistiocytosis and hypereosinophilic syndrome have been associated with hematologic neoplasms and are respectively related to an overproduction of the cytokines Thelper 1 (Th1) and Th2 by tumor cells or reactive cells. To our knowledge, this is the first time a case of a peripheral T-cell lymphoma consecutively associated with both paraneoplastic conditions has been reported. Importantly, in this case when the lymphoma exclusively involved the bone marrow, severe paraneoplastic systemic damage, a CD8+ suppressor/cytotoxic phenotype and a hypereosinophilia not related to high levels of interleukin (IL)-5 was found. Interestingly, progression of the lymphoma coincided with an increase in the serum levels of several Th2 cytokines and IL-2, a decrease in tumor necrosis factor and granulocyte-macrophage colony-stimulating factor levels and the onset of a hypereosinophilic syndrome.