The rationale of this study is to provide an overview on PCL (Primary Cardiac Lymphoma) in Italy, trying to shed light on unknown aspects of the disease and on unanswered questions about its management that could be helpful in clinical practice.

Primary cardiac lymphoma (PCL), an extranodal lymphoma involving only the heart (with possible involvement of the pericardium) is a rare entity, accounting for 2% of primary cardiac tumors and 0.5% of extranodal lymphomas. It is more frequent in males; clinical presentation is predominated by cardiac symptoms. The most common histology is Diffuse Large B Cell Lymphoma (DLBCL). Being DLBCL the most frequent histology, patients are usually treated with R-CHOP (rituximab - cyclophosphamide, doxorubicin, vincristine and prednisone) or R-CHOP-like chemoimmunotherapy regimens, with an historically poor outcome, although in the last years survival rates significantly increased. Due to the rarity of this condition, isolated case reports and a few reviews have been published so far, that in most cases included a population collected in a wide period of time, heterogeneously managed both in terms of treatments received and follow-up, and who often did not strictly respect the criteria of PCL. Indeed, while some aspects of PCL are well-known, especially the ones concerning its clinical presentation, a few topics deserve more in-depth analysis. The rationale of this study is to provide an overview on PCL in Italy, trying to shed light on unknown aspects of the disease and on unanswered questions about its management that could be helpful in clinical practice.

Inclusion Criteria:

• Diagnosis of PCL (any histotype) defined as an extranodal lymphoma involving only the heart with possible involvement of the pericardium.
• Age ≥18 years.
• Diagnosis histologically confirmed. Cytofluorimetry analysis of pericardial fluid showing phenotypic features consistent with a primary cardiac lymphoma is permitted if a biopsy sample is not feasible/available for diagnosis; monoclonality is not accepted as a surrogate for diagnosis.
• Date of diagnosis: from 1st January 2000 to 31st December 2020.
• Only patients treated in first-line with chemoimmunotherapy regimens including an anti-CD20 monoclonal antibody are eligible for the study.
• Signed written informed consent (in case of unreachable subject please see chapter 11.2)

Exclusion Criteria:

• Secondary cardiac involvement from lymphoma; primary mediastinal lymphoma with pericardial infiltration or other lymphomas with involvement of the pericardium/the heart by contiguity and primary effusion lymphoma are not included in this study.
• Patients treated with chemotherapy regimens that did not include an anti-CD20 monoclonal antibody as first-line therapy.
• Refuse to sign a written informed consent

Patient affected by primary cardiac lymphoma from 1st January 2000 to 31st December 2020.