Primary lung adenocarcinoma with massive lymphocyte infiltration

Area of Science:

• Oncology
• Pathology
• Immunology

Background:

• Adenocarcinoma is the most common type of lung cancer.
• Primary lung adenocarcinomas can exhibit diverse histological patterns.
• The prognostic significance of tumor-infiltrating lymphocytes in lung adenocarcinoma is an area of ongoing research.

Purpose of the Study:

• To describe the clinicopathologic features of a rare subtype of lung adenocarcinoma characterized by massive lymphocyte infiltration.
• To evaluate the prognosis of patients with this specific subtype of lung adenocarcinoma.
• To investigate the immunophenotype of the infiltrating lymphocytes.

Main Methods:

• Retrospective analysis of 6 cases of primary lung adenocarcinoma with massive lymphocyte infiltration.
• Histopathological examination including immunohistochemical staining for CD3, CD20, latent membrane protein-1, bcl-2, and Epstein-Barr virus-encoded small RNA-1.
• Clinical data review including follow-up periods and patient outcomes.

Main Results:

• The identified adenocarcinoma subtype occurred in 0.7% of surgically resected primary lung adenocarcinomas.
• Tumors were peripherally located, with lymph node metastasis in 4 out of 6 cases.
• All patients survived without recurrence, with a mean follow-up of 49.8 months, despite advanced pathologic stage.
• Histology showed destroyed cancer epithelium and lung parenchyma by infiltrating lymphocytes and inflammatory cells.
• Immunohistochemistry confirmed infiltrating lymphocytes (CD3+, CD20+) and ruled out Epstein-Barr virus association.

Conclusions:

• Primary lung adenocarcinoma with massive lymphocyte infiltration is a distinct clinicopathologic entity.
• This subtype is associated with a favorable prognosis, even in advanced stages.
• Further research is warranted to understand the mechanisms underlying the good outcome in these cases.