[Primary nasal natural killer/T-cell lymphomas: classification and clinicopathological features]

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• Nasal NK/T-cell lymphomas are rare malignancies with challenging histological diagnosis, often misdiagnosed as chronic inflammation.
• The disease can lead to severe facial destruction and is fatal if untreated, historically termed 'lethal midline granuloma'.

Observation:

• This study reviews clinical features, histopathology, and classification of primary nasal NK/T-cell lymphomas.
• A case report is presented alongside current literature to illustrate diagnostic and therapeutic aspects.

Findings:

• Immunophenotyping is essential, revealing tumor cells positive for CD56, cytoplasmic CD3epsilon, CD2, and cytotoxic molecules.
• Epstein-Barr virus (EBV) infection is uniformly present, detectable by EBER in situ hybridization.
• Radiochemotherapy offers therapeutic options, with 50% 2- and 5-year survival rates in early stages (I and II).

Implications:

• Early and accurate diagnosis through immunohistochemistry and molecular genetic analysis is critical for determining prognosis.
• Advanced stages of nasal NK/T-cell lymphoma have a very poor prognosis, highlighting the need for timely intervention.