Composite T lymphoblastic leukemia/lymphoma and diffuse large B-cell lymphoma: case report

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• Composite lymphomas are rare neoplasms characterized by the coexistence of two or more distinct lymphoma types within the same tissue.
• T-lymphoblastic leukemia/lymphoma (T-LBL) and diffuse large B-cell lymphoma (DLBCL) are distinct lymphoid malignancies with different origins and treatment approaches.

Observation:

• A 72-year-old woman presented with generalized lymphadenopathy, splenomegaly, and ascites, with elevated lactate dehydrogenase and soluble interleukin-2 receptor levels.
• Lymph node biopsy revealed a dual cell population consistent with a composite lymphoma, comprising T-LBL and DLBCL.
• Flow cytometry and immunohistochemistry confirmed the presence of both T-LBL (CD1a+, CD3+, CD4+, CD8+, TdT+) and DLBCL (CD19+, CD20+, CD23+, bcl-2+, bcl-6+, MUM1+, Igκ+).

Findings:

• Polymerase chain reaction analysis demonstrated monoclonal T-cell receptor γ and immunoglobulin heavy chain rearrangements in the same specimen, confirming the dual lymphoid origin.
• The patient received eight cycles of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy.
• Complete remission was achieved and maintained for 20 months post-diagnosis, with no signs of recurrence.

Implications:

• This case represents a unique instance of primary composite lymphoma involving T-LBL and DLBCL, a combination not previously reported.
• The successful treatment with R-CHOP suggests this regimen may be effective for managing such rare composite lymphomas.
• Further research into the pathogenesis and optimal management strategies for composite lymphomas is warranted.