Head-to-head: Should Ki67 proliferation index be included in the formal classification of pulmonary neuroendocrine neoplasms?
Giuseppe PelosiWilliam D TravisPublished in: Histopathology (2024)
The reporting of lung neuroendocrine neoplasms (NENs) according to the 2021 World Health Organisation (WHO) is based on mitotic count per 2 mm 2 , necrosis assessment and a constellation of cytological and immunohistochemical details. Accordingly, typical carcinoid and atypical carcinoid are low- to intermediate-grade neuroendocrine tumours (NETs), while large-cell neuroendocrine carcinoma (NEC) and small-cell lung carcinoma are high-grade NECs. In small-sized diagnostic material (cytology and biopsy), the noncommittal term of carcinoid tumour/NET not otherwise specified (NOS) and metastatic carcinoid NOS have been introduced with regard to primary and metastatic diagnostic settings, respectively. Ki-67 antigen, a well-known marker of cell proliferation, has been included in the WHO classification as a non-essential but desirable criterion, especially to distinguish NETs from high-grade NECs and to delineate the provisional category of carcinoid tumours/NETs with elevated mitotic counts (> 10 mitoses per mm 2 ) and/or Ki-67 proliferation index (≥ 30%). However, a wider use of this marker in the spectrum of lung NENs continues to be highly reported and debated, thus witnessing a never-subsided attention. Therefore, the arguments for and against incorporating Ki-67 in the classification and clinical practice of these neoplasms are discussed herein in detail.
Keyphrases
- high grade
- low grade
- machine learning
- deep learning
- neoadjuvant chemotherapy
- cell proliferation
- cell cycle
- fine needle aspiration
- single cell
- clinical practice
- small cell lung cancer
- squamous cell carcinoma
- cell therapy
- healthcare
- public health
- signaling pathway
- nitric oxide synthase
- ultrasound guided
- optic nerve
- pulmonary hypertension
- mental health
- preterm infants
- peripheral blood
- working memory
- emergency department
- nitric oxide
- mesenchymal stem cells
- adverse drug
- bone marrow
- preterm birth
- social media