Abstract

Objective: To investigate the clinical and paraclinical characteristics of patients with PML treated at National Institute of Hematology and Blood Transfusion between 2020 and 2025.

Methods: We conducted a retrospective descriptive study of 40 newly diagnosed PML patients from January 2020 to June 2025.

Results: The male-to-female ratio was 1:1.4, and 60% of patients were aged 16–30 years. Primary mediastinal large B-cell lymphoma (PMBCL) was the most frequent subtype (50%). Most patients were diagnosed within one month of symptom onset, commonly presenting with mediastinal compression. Tumors were mainly located in the anterior and anterosuperior mediastinum (75%), and 35% had bulky disease (>10 cm). Pleural and pericardial effusions occurred in 67.5% and 32.5% of cases, respectively. Elevated LDH and β2-microglobulin levels were observed in 90% and 50% of patients. Peripheral blood and bone marrow involvement were uncommon, mild anemia was present in 35%. Immunohistochemistry was essential for subtype differentiation.

Conclusions: Primary mediastinal lymphoma mainly occurs in young individuals and commonly presents with symptoms of mediastinal compression. Primary mediastinal large B-cell lymphoma (PMBCL) is the most frequently observed subtype. Diagnosis and classification rely primarily on histopathological examination combined with immunohistochemistry.