Background. Neoplastic diseases and infections have become the leading causes of death in SLE in recent decades. Cancers and infections were also precipitating factors in the development of catastrophic APS. Case summary. We describe two patients: one of them had definite antiphospholipid syndrome (APS) and melanoma and the other had definite systemic lupus erythematosus (SLE) with APS, melanoma, infiltrative tuberculosis and severe Herpes Zoster (HZ). Management of patients with SLE concurrent with APS is a rather difficult task in rheumatology practice. In addition to kidney damage and cardiovascular disease, infections and malignancies are a significant cause of death in this cohort. The risk of malignancy in SLE is of considerable interest, since the immune and genetic pathways underlying the pathogenesis of this disease, as well as the immunosuppressive therapy, can significantly alter the risk. Both patients still had reliable APS, confirmed by triple-positive aPL. Both were at high risk of thrombosis. Patients ' adherence to treatment with direct oral anticoagulants and relapse of thrombosis on the background of rivaroxaban were noted. Conclusion. The cases where cancer or tuberculosis develops in the presence of rheumatic diseases are not so common and complicate the possibilities of therapeutic approaches, limiting the use of drugs that are not regulated by clinical recommendations.