Sinonasal malignant lymphomas: a distinct clinicopathological category

Area of Science:

• Oncology
• Hematology
• Pathology

Background:

• Sinonasal lymphomas are a specific category of extranodal lymphomas affecting the head and neck.
• While uncommon in Western nations, they are the second most prevalent extranodal lymphoma in Asian populations, following gastrointestinal lymphomas.
• Immunohistochemistry has enabled classification into B-cell, T-cell, and natural killer (NK) cell phenotypes.

Purpose of the Study:

• To differentiate sinonasal lymphomas based on immunophenotype.
• To describe the epidemiological and clinical characteristics of different sinonasal lymphoma subtypes.
• To highlight the diagnostic challenges and treatment approaches for these tumors.

Main Methods:

• Utilized immunohistochemistry to classify sinonasal lymphomas.
• Reviewed epidemiological data regarding prevalence in different global populations.
• Analyzed clinical presentation, growth patterns, and patient demographics.

Main Results:

• B-cell phenotype lymphomas are predominantly found in the paranasal sinuses, more common in Western countries.
• T/NK-cell phenotype lymphomas are prevalent in Asian and South American populations, typically located in the nasal cavity.
• These aggressive tumors exhibit angioinvasion, necrosis, and bony erosion, historically misdiagnosed as lethal midline granuloma.

Conclusions:

• Sinonasal lymphomas exhibit distinct epidemiological and clinical features based on immunophenotype.
• The T/NK-cell phenotype is more common in Asia and South America, presenting aggressively in the nasal cavity.
• Despite aggressive features, prognosis can be favorable compared to nodal lymphomas, with combined radiation and chemotherapy treatment.