Can peripheral T-cell lymphomas be morphologically subclassified? A morphometric approach to 21 cases

Area of Science:

• Hematopathology
• Oncology
• Cell Biology

Background:

• Non-Hodgkin's peripheral T-cell malignant lymphoma (PTCL) comprises heterogeneous subtypes.
• Accurate classification of PTCL is crucial for understanding disease biology and guiding treatment.
• Morphological assessment of nuclear features can aid in distinguishing between PTCL subtypes.

Purpose of the Study:

• To investigate the utility of morphometric analysis of nuclear sizes and shapes in classifying peripheral T-cell malignant lymphoma (PTCL).
• To differentiate between monomorphic medium-cell, pleomorphic, and monomorphic large-cell PTCL subtypes using quantitative morphological parameters.
• To compare nuclear morphology and mitotic activity across different PTCL subclasses.

Main Methods:

• Morphometric analysis of nuclear sizes and shapes on semithin lymph node sections from 21 PTCL patients.
• Classification of PTCL according to Wright and Isaacson's proposals.
• Comparative analysis of nuclear area, coefficient of variation, nuclear size histograms, and mitotic counts between PTCL subclasses.
• Reference cases included 20 B-cell ML and 3 Sézary syndrome cases.

Main Results:

• Morphometric analysis successfully distinguished the three PTCL subclasses: monomorphic medium-cell, pleomorphic, and monomorphic large-cell.
• Pleomorphic PTCL exhibited significantly higher nuclear areas and coefficients of variation compared to monomorphic medium-cell PTCL (p < 0.01).
• Monomorphic large-cell PTCL was identifiable by distinct nuclear size histograms, and pleomorphic PTCL showed more numerous mitoses (p < 0.05).

Conclusions:

• Morphometric analysis provides a quantitative and objective method for demonstrating the morphological distinctiveness of PTCL subclasses.
• The findings support the classification of peripheral T-cell lymphomas based on nuclear morphometry.
• Further research is needed to determine the biological and clinical significance of these morphologically distinct PTCL subclasses.