Diffuse large cell lymphomas (reticulum cell sarcomas, histiocytic lymphomas). Correlation of morphologic features...

Area of Science:

• Hematopathology
• Oncology
• Cell Biology

Background:

• Diffuse large cell lymphoma (DLCL) is a heterogeneous group of non-Hodgkin lymphomas.
• Accurate classification is crucial for prognosis and treatment.
• Electron microscopy (EM) offers detailed ultrastructural insights into cellular morphology.

Purpose of the Study:

• To correlate electron microscopic findings with immunophenotypic and cytoplasmic immunoglobulin characteristics in DLCL.
• To elucidate the ultrastructural basis of DLCL heterogeneity.
• To identify specific EM features associated with different DLCL subtypes.

Main Methods:

• Analysis of 15 DLCL cases using electron microscopy.
• Correlation of ultrastructural findings with surface immunotyping (B cell, null, T cell, H cell).
• Assessment of cytoplasmic immunoglobulin content and other morphologic features.

Main Results:

• B-cell and some null lymphomas showed abundant polyribosomes and rough endoplasmic reticulum (RER).
• Concentric RER was observed in immunoglobulin-containing B-cell lymphomas.
• T-cell lymphomas exhibited hyperlobulated nuclei and abundant smooth to rough ER; H-cell lymphoma showed monocytic-macrophagic features.

Conclusions:

• DLCL is ultrastructurally diverse, with distinct features correlating with immunotype.
• EM can aid in differentiating DLCL subtypes, particularly B-cell and T-cell lymphomas.
• Findings suggest follicular center cell or early plasma cell origins for most B-cell DLCLs in this series.