Endobronchial large cell neuroendocrine carcinoma

Area of Science:

• Pulmonology
• Oncology
• Pathology

Background:

• Neuroendocrine lung tumors are classified by morphology and mitotic count per World Health Organization guidelines.
• Differentiating between tumor types like atypical carcinoid and large cell neuroendocrine carcinoma is crucial for prognosis.

Observation:

• A 58-year-old non-smoking male presented with recurrent pneumonia and an endobronchial mass.
• Histological examination revealed a tumor with neuroendocrine morphology and 20 mitoses per 10 high-power fields, leading to a large cell neuroendocrine carcinoma diagnosis.

Findings:

• Despite high mitotic count, the tumor exhibited carcinoid-like morphology, endobronchial location, and a favorable clinical course.
• These features were more consistent with atypical carcinoid than large cell neuroendocrine carcinoma.

Implications:

• The case suggests current histologic criteria for neuroendocrine lung tumors may require reevaluation.
• A higher mitotic rate might be permissible for atypical carcinoid classification, potentially improving diagnostic accuracy.