Non-Hodgkin's Lymphoma is a neoplasm that originates from mutations in the lymphatic tissue in the B and T progenitor cells, whose clinical manifestation is characterized by the enlargement of lymph nodes and general systemic symptoms. Otherwise, scimitar syndrome (SS) is a rare variant of a group of congenital cardiovascular disorders known as partial anomalous pulmonary venous return, in which the pulmonary venous flow ends in the right atrium rather than the left atrium. This report describes a 60-year-old patient, born in Santarém (PA), who was diagnosed with diffuse large-cell non-Hodgkin's Lymphoma with immunophenotype B, with a germinal center type IIIB pattern - CD20, CD10, BCL2 and BCL6 positively diffuse and Kl -67 positive around 60 to 70%. After diagnosis, she received systemic infusion chemotherapy with R-CHOP (Rituximab, Cyclophosphamide, Doxorubicin, Vincristine and Prednisone) according to current guidelines. During the tomographic scan, the diagnosis of associated Scimitar Syndrome was made. Radiographic findings such as hypoplastic right lung, anomalous pulmonary venous drainage through the inferior vena cava, anomalous pulmonary irrigation through a branch of the descending aorta, dextrocardia (deviation of the heart to the right side of the body) characterize the Scimitar Syndrome, have been described in the literature and identified in the referred clinical case. The absence of identifiable symptoms in the clinical history attributed to the syndrome may justify its identification by an incidental radiological finding in an imaging scan of Non-Hodgkin's Lymphoma. After the diagnosis of lymphoma, according to current guidelines, he completed the proposed chemotherapy regimen with a complete response and remains in outpatient follow-up. Furthermore, the association of the syndrome with the occurrence of malignant neoplasms gives scientific relevance and rare character to the aforementioned case report.