Angioimmunoblastic T-Cell Lymphoma

Siba El Hussein, MD
2 min readDec 10, 2022

Lessons From the Friday Unknowns

Histologic sections show a large lymph node that is almost completely replaced by lymphoma. Scattered reactive follicles are present surrounded by the neoplasm. The neoplasm is composed predominantly of intermediate-size cells with abundant pale cytoplasm. Some high endothelial vessel proliferation is present. Eosinophils and plasma cells are rare.

The neoplastic cells are positive for CD3, CD4, CD5, CD7, CD30 (subset, 10–20%), PD1, ICOS, CXCL13, BCL–6 (subset), BCL–2 and cyclin D1 (small subset, <5%), and are negative for CD8, CD10, CD20, CD21, CD23, CD56 and PAX-5. The antibody specific for Ki-67 shows a proliferation rate of approximately 60–70%. The antibody specific for CD21 and CD23 show some disordered networks of follicular dendritic cells.

Rare small cells are positive but most likely represent bystander benign lymphocytes. The neoplastic cells are negative for EBER.

CD3
CD21

Flow cytometry immunophenotypic studies showed 93.6% lymphocytes positive for CD2, CD4, CD5, CD7 (dim) and CD38, and negative for CD3, CD8 and CD56.

Molecular analysis of the TRB showed monoclonal TRB are rearrangements.

In summary, we can establish a diagnosis of peripheral T-cell lymphoma and the immunophenotype supports a T follicular helper cell immunophenotype. The neoplasm also has some morphologic features highly suggestive of angioimmunoblastic T-cell lymphoma,but lacks eosinophils and plasma cells as are commonly seen angioimmunoblastic T-cell lymphoma.

Link to digital slides: bit.ly/3Hi2bLG | Case 2

--

--

Siba El Hussein, MD

Hematopathology | Cytopathology | Molecular pathology | Digital pathology | Data science | Machine learning