A 64-year-old woman presented with fatigue, cyclic fevers, unintentional weight loss, and bilateral axillary lymphadenopathy on routine mammogram. One year earlier, she was hospitalized for fever of unknown origin and found to have bilateral axillary lymphadenopathy and pleural effusions. EBV IgG was positive, and symptoms resolved after empiric antibiotics.
Needle biopsy of the right axilla and breast revealed atypical lymphoid tissue. Excisional biopsy of the right axillary node showed a small CD10⁺ T-cell population (8%) with uniform TRBC1 loss; TCR γ/β rearrangements were clonal. Immunohistochemistry showed PD-1 and ICOS positivity, confirming angioimmunoblastic T-cell lymphoma (AITL). PET/CT demonstrated hypermetabolic lymphadenopathy in the neck, chest, abdomen, and pelvis, with splenic, breast uptake (Max SUV 7.4). Bone marrow was mild hypocellular with normal trilineage hematopoiesis and normal karyotype. EBV PCR was low positive (< 35 IU/mL). HTLV and HIV were negative.
Lymphoma NGS identified characteristic mutations of AITL including RHOA p.G17V(5.44%), TET2 p.Q866*(6.43%), TET2 p.A1159P(4.33%), CARD11 p.G612R(48.16%), and CREBBP p.R1964H(51.93%). A brief prednisone course (20 mg,5 days) led to symptom and laboratory normalization. Repeat inguinal node biopsy two months later confirmed AITL, pattern 1, and CT showed complete lymph node resolution. The patient elected active surveillance, and after two years of six-monthly imaging follow-up, she remains in clinical remission without evidence of disease.
AITL demonstrates marked biological heterogeneity, from indolent, immune-reactive pattern 1 lesions to malignant patterns 2–3. This patient's durable remission after only corticosteroid exposure suggests a potentially reversible immune-reactive phase of TFH-derived lymphoma and highlights the biologic plasticity of early AITL.
