Clonal B-cell population in a reactive lymph node in acquired immunodeficiency syndrome

Area of Science:

• Oncology
• Immunology
• Pathology

Background:

• A 40-year-old HIV-positive female with a history of follicular lymphoma presented with cervical lymphadenopathy.
• Previous treatment included chemotherapy and rituximab for follicular B-cell non-Hodgkin lymphoma.

Observation:

• Ultrasound-guided fine-needle cytology revealed atypical lymphoid proliferation.
• Flow cytometry showed a specific immunophenotype, and FDG-PET/CT indicated metabolic activity.
• Histology of the excised lymph node demonstrated reactive hyperplasia, not lymphoma, with no IgH rearrangement by PCR.

Findings:

• The patient's cervical lymph node swelling was ultimately diagnosed as reactive hyperplasia, despite initial concerning findings.
• Clonal B-cell populations can occur in non-lymphomatous processes, particularly in immunocompromised individuals.

Implications:

• This case underscores the importance of integrating radiological, cytological, flow cytometry, and histological data for accurate diagnosis in complex cases.
• Careful clinical correlation is essential, especially in patients with immunodeficiency syndromes or autoimmune conditions, to avoid misdiagnosis of malignancy.