ABSTRACT
Primary cardiac synovial sarcoma is an extremely rare tumor with a higher incidence in young men. The mean age of occurrence is 32 years. Synovial sarcomas are tumors with high aggressiveness, proliferate rapidly and metastasize to regional and distant lymph nodes or surrounding organs. The typical location of synovial sarcoma of the heart is the atrial and ventricular septum. Its size, the degree of infiltration of the surrounding tissues and the presence of metastases influence clinical symptoms, which are very non-specific. The low specificity of the symptoms complicates the clinical diagnosis and in most cases the tumor is detected during its progression or incidentally. The final diagnosis is based on histological examination. The primary and only method of treatment is a surgical solution with an effort to completely resect the tumor, followed by aggressive palliative chemotherapy. In the following paper, we present a case report of a 32-year-old man who was diagnosed with synovial cardiac sarcoma only on the basis of exacerbation of non-specific subjective complaints due to the complication in the form of of aneurysmal bleeding of the tumor mass.