Introduction: Primary mediastinal large B cell lymphoma is a rare highly aggressive form of non-Hodgkin lymphoma and occurs in 5-7% of all diffuse large B lymphoma and 2% of all non-Hodgkin lymphomas. Originates from thymic medullary cells and has its own histogenesis. Typically affects young women in the third and fourth decade of life. Superior vena cava syndrome is present in more than 50% of cases, with swelling of face, hands, deep venous thrombosis, dyspnea, dysphagia, chest pain, headache and cough. Diagnosis is made by histopathological analysis and immunohistochemical surgical biopsy specimens obtained mediastinoscopy. Timely treatment with cycles of monoclonal antibody and chemotherapy is requirement to relapse and stable state.

Case outline: Patient, 37 years old, came for the first time for review at General practice because she has been repeatedly visited emergency service due to coughing, feeling that something is strangling, the lack of air pressure and pain in the head and swelling of face and neck. Started detailed diagnostics. Radiologically determined mediastinal tumor, computed tomography confirmed it and sent to the referral Institute where video-assisted thoracic surgery and patho histology diagnosed PMBCL CSII AM +. Administered six cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone therapy protocols submitted by the expected side effects. Control positron emission tomography found that the tumor mass completely withdrawn. In remission for two years, have a good feeling and occurs at regular checkups.

Conclusion: General practice has a big responsibility in recognizing early symptoms of malignant disease that accelerates
the diagnosis and timely start of treatment.