Natural killer cell lymphoma in the duodenum

Area of Science:

• Hematology
• Oncology
• Immunology

Background:

• Non-Hodgkin lymphoma (NHL) encompasses a diverse group of lymphoid malignancies.
• Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a distinct entity often associated with specific demographic and geographic factors.
• Gastrointestinal involvement by NK/T-cell lymphoma is exceptionally rare.

Observation:

• A 71-year-old woman presented with duodenal non-Hodgkin lymphoma.
• Immunohistochemical analysis revealed lymphoma cells positive for CD2, cytoplasmic CD3, CD7, and CD56, with a negative T-cell receptor gene rearrangement.
• Morphological features, including high nuclear-to-cytoplasmic ratio and irregular nuclear outlines, supported an NK cell origin.

Findings:

• The duodenal lymphoma was characterized as a CD56-positive lymphoma, consistent with NK cell lineage.
• The patient received intensive chemotherapy but experienced a rapid decline, succumbing three weeks post-diagnosis.
• This case represents an extremely rare extranasal manifestation of NK/T-cell lymphoma.

Implications:

• Extranasal NK/T-cell lymphomas, particularly those in the gastrointestinal tract, are rare and associated with a poor prognosis.
• The heterogeneity of extranodal NK/T-cell lymphomas underscores the need for further research into their subclassification and treatment strategies.
• This case highlights the diagnostic challenges and aggressive clinical course of rare extranasal NK/T-cell lymphomas.