Hematolymphoid neoplasms in effusion cytology

Area of Science:

• Cytopathology
• Hematopathology
• Oncology

Background:

• Hematolymphoid neoplasms (HLNs) presenting in body effusions are uncommon but can be the initial disease manifestation.
• Effusion cytology offers a potential avenue for early diagnosis and management of HLNs.

Purpose of the Study:

• To investigate the cytomorphology of HLNs in effusion samples.
• To identify common HLN types and anatomical sites involved in effusions.
• To determine characteristic cytologic features for subclassification of HLNs in effusions.

Main Methods:

• Analysis of 24 biopsy-proven HLN cases with malignant effusions and 8 suspicious cases.
• Review of effusion cytology smears for features like cellularity, nuclear characteristics, and mitotic activity.
• Comparison of cytomorphologic findings between high-grade and low-grade HLNs.

Main Results:

• Diffuse large B-cell lymphoma (37%) and peripheral T-cell lymphoma (25%) were the most frequent HLNs in effusions.
• Pleural effusions (75%) were the most common site, followed by peritoneal (20.8%).
• Characteristic features included high cellularity, enlarged lymphoid cells, and high-grade tumors showing increased mitosis and karyorrhexis.

Conclusions:

• HLNs exhibit distinct cytomorphology in effusions, aiding subclassification.
• Distinguishing reactive effusions from low-grade lymphomas solely on cytology can be challenging.
• Immunocytochemistry, flow cytometry, and molecular techniques are valuable for definitive diagnosis.