Splenic involvement by aggressive malignant lymphomas of B-cell and T-cell types. A morphologic and immunophenotypic...

Area of Science:

• Hematology
• Oncology
• Pathology

Background:

• Aggressive non-Hodgkin's lymphomas can involve the spleen, presenting diagnostic challenges.
• Distinguishing between B-cell and T-cell lymphomas is crucial for appropriate treatment and prognosis.
• Morphologic analysis of splenic lymphomas is essential for accurate classification.

Purpose of the Study:

• To identify consistent morphologic differences between B-cell and T-cell aggressive splenic lymphomas.
• To evaluate the predictability of lymphoma cell lineage based on splenic morphology.
• To investigate unusual presentations of splenic lymphomas that may mimic other conditions.

Main Methods:

• Analysis of 16 spleens affected by aggressive non-Hodgkin's lymphomas (large cell and mixed cell types).
• Immunologic phenotyping (T-cell vs. B-cell) derived from cell suspensions or frozen tissue.
• Detailed morphologic assessment of lymphoma distribution within the spleen and cytologic features.

Main Results:

• Morphologic features such as epithelioid histiocytic reactions and T-zone confinement suggested a T-cell phenotype.
• Features like discrete white pulp nodules and specific cytologic characteristics indicated a B-cell phenotype.
• Four cases with diffuse red pulp distribution and erythrophagocytosis, initially suspected as T-cell lymphomas, were predominantly B-cell lineage.

Conclusions:

• The B-cell or T-cell nature of aggressive splenic lymphomas is often predictable from distributional and cytologic features.
• Certain splenic lymphomas can exhibit morphologic characteristics indistinguishable from those found in lymph nodes.
• Careful morphologic evaluation is key, but immunophenotyping remains essential for definitive diagnosis.