Hydroa-like lymphoma with CD56 expression

Area of Science:

• Pediatric Oncology
• Dermatology
• Hematology

Background:

• Hydroa-like lymphoma is an extremely rare, aggressive T-cell lymphoma primarily affecting children in Latin America and Asia.
• It is characterized by ulcerative blistering lesions on sun-exposed and non-sun-exposed skin.
• Unlike classical hydroa vacciniforme, it is associated with systemic T-cell lymphoma expressing CD4 or CD8.

Observation:

• Two pediatric cases of hydroa-like lymphoma presented with atypical CD56 expression, resembling natural killer (NK) cell lymphomas.
• Patients, both 9-year-old boys, had a history of ulcerative blistering lesions since age 3.
• Skin biopsies revealed atypical lymphocytes with a CD3+, CD56+, CD30+ phenotype, lacking CD4 and CD8.

Findings:

• The study identified two unusual cases of hydroa-like lymphoma with a natural killer cell phenotype (CD56+).
• These cases differed from previously described hydroa-like lymphomas, which are typically T-cell derived (CD4+ or CD8+).
• Both patients remained alive with disease one year post-diagnosis.

Implications:

• Hydroa-like lymphoma with an NK-cell phenotype may share similar outcomes to T-cell derived hydroa-like lymphoma.
• The prognosis for this NK-cell variant might be more favorable than for classical aggressive NK cell lymphomas.
• This finding expands the understanding of hydroa-like lymphoma subtypes and their clinical behavior.