CD56-negative extranodal nasal type NK/T-cell lymphoma.

Area of Science:

• Hematology
• Pediatric Oncology
• Pathology

Background:

• Extranodal natural killer (NK)/T-cell lymphoma, nasal type, is a rare lymphoid malignancy primarily affecting Asian adults.
• This aggressive lymphoma is characterized by extranodal involvement, frequently affecting the nasal cavity.

Observation:

• A case study of a 4-year-old Native American male presenting with facial swelling, lymphadenopathy, and fevers.
• Pathologic examination revealed neoplastic lymphoid cells expressing CD3, CD8, TIA-1, and EBV-encoded RNA.
• Notably, the neoplastic cells lacked CD56 expression, an atypical feature for this lymphoma subtype.

Findings:

• The pediatric patient exhibited an aggressive clinical course, failing multiagent chemotherapy.
• The case represents a rare instance of extranodal NK/T-cell lymphoma, nasal type, in a child with an unusual immunophenotype (CD56-negative).
• The findings underscore the heterogeneity of NK/T-cell lymphomas, even in pediatric populations.

Implications:

• This case highlights the importance of considering extranodal NK/T-cell lymphoma, nasal type, in pediatric patients with unexplained lymphoid neoplasms, even with atypical immunophenotypes.
• The lack of CD56 expression may present diagnostic challenges and warrants further investigation into alternative diagnostic markers.
• Further research is needed to understand the biology and optimize treatment strategies for CD56-negative NK/T-cell lymphomas in children.