Related Experiment Video
Updated: Dec 24, 2025
06:51
Utilizing 18F-FDG PET/CT Imaging and Quantitative Histology to Measure Dynamic Changes in the Glucose Metabolism in Mouse Models of Lung Cancer
Published on: July 21, 2018
18.4K
Transcriptomic data helps refining classification of pulmonary carcinoid tumors with increased mitotic counts
Olga Sazonova1, Venkata Manem1, Michèle Orain1
1Quebec Heart and Lung Institute Research Center, Quebec City, QC, Canada.
Summary
Pulmonary neuroendocrine tumor classification is challenging for borderline cases. This study suggests tumors with carcinoid features and low mitotic counts should be classified as carcinoids, not large cell neuroendocrine carcinoma (LCNEC).
Area of Science:
- Pulmonary pathology
- Oncology
- Molecular diagnostics
Background:
- Pulmonary neuroendocrine neoplasms (NENs) are WHO-classified into typical/atypical carcinoids, large cell neuroendocrine carcinoma (LCNEC), and small cell lung cancer (SCLC).
- LCNEC with low mitotic counts and carcinoid-like morphology present classification challenges due to rarity and limited validation of current grading systems.
Purpose of the Study:
- To investigate the clinicopathological and transcriptomic profiles of pulmonary neuroendocrine tumors, particularly those in the diagnostic gray zone.
- To evaluate the current WHO classification system for pulmonary NENs with borderline features.
Main Methods:
- Analysis of 18 lung resection specimens diagnosed as carcinoids or LCNEC, including four borderline tumors (10-30 mitoses/mm²).
- Comprehensive morphological and immunohistochemical (IHC) evaluation.
- Unsupervised clustering of tumor-based transcriptomic profiles.
Main Results:
- Transcriptomic clustering identified two distinct molecular groups: C1 (low proliferation) and C2 (high proliferation).
- C1 included carcinoids and borderline tumors; C2 included LCNEC and one borderline tumor.
- Patients in C1 demonstrated significantly better recurrence-free survival than those in C2 (20% vs 75% recurrence).
- Three of four borderline tumors exhibited carcinoid-like features, supporting reclassification.
Conclusions:
- The current WHO diagnostic guidelines are suboptimal for classifying pulmonary NENs with increased proliferative index and carcinoid morphology.
- Pulmonary neuroendocrine tumors with carcinoid-like features and mitotic counts <20/mm² should be considered pulmonary carcinoids, not LCNEC.
