Pulmonary Neuroendocrine Tumors.

Area of Science:

• Pulmonary Pathology
• Oncology
• Diagnostic Histopathology

Background:

• Pulmonary neuroendocrine tumors (PNETs) are common in biopsy and resection specimens.
• The World Health Organization (WHO) classification is the global standard for diagnosing PNETs.
• Current WHO criteria present practical difficulties and controversies in daily application.

Purpose of the Study:

• To review the WHO classification criteria for pulmonary neuroendocrine tumors.
• To highlight practical difficulties and controversies associated with the current classification.
• To emphasize a context-specific diagnostic approach, particularly for small biopsies and frozen sections.

Main Methods:

• Review of the World Health Organization (WHO) classification for pulmonary neuroendocrine tumors.
• Analysis of diagnostic challenges in small biopsy and resection specimens.
• Discussion of differential diagnoses in challenging clinical contexts.

Main Results:

• WHO criteria are primarily based on resected specimens, not typical clinical scenarios.
• Diagnostic difficulties are frequently encountered in small biopsies and frozen sections.
• A practical, context-aware approach is crucial for accurate PNET diagnosis.

Conclusions:

• The WHO classification for pulmonary neuroendocrine tumors requires careful application in practice.
• Understanding the limitations of criteria in small biopsies is essential.
• A pragmatic approach aids in overcoming diagnostic challenges for PNETs.