Lung Cancer — Small Cell MCQ — NEET PG Practice Question | NEETPGAI
Lung Cancer — Small Cell
medium
microscope Pathology
A 62-year-old male smoker presents with progressive dyspnea, chest pain, and hemoptysis. Chest X-ray shows a central hilar mass with mediastinal widening. Bronchoscopic biopsy reveals small round cells with scant cytoplasm, fine chromatin, and frequent mitoses. Which is the most common site of origin for small cell lung cancer (SCLC)?
A. Central airways and main bronchi
B. Visceral pleura
C. Peripheral lung parenchyma
D. Lung apex
Explanation
Site of Origin in Small Cell Lung Cancer
Key Point
Small cell lung cancer (SCLC) arises from neuroendocrine cells (Kulchitsky cells) located predominantly in the central airways, particularly around the main and lobar bronchi.
Anatomical Distribution
SCLC shows a characteristic central location pattern:
Table
Feature
SCLC
NSCLC (Adenocarcinoma)
Most common site
Central airways (main/lobar bronchi)
Peripheral lung (distal airways)
Histology origin
Neuroendocrine cells (Kulchitsky)
Mucous glands, respiratory epithelium
Mediastinal involvement
Frequent (early)
Late
Presentation
Hilar/mediastinal mass
Peripheral nodule
Why Central Airways?
1.
Neuroendocrine cell distribution — Kulchitsky cells are concentrated in the bronchial epithelium of central airways.
2.
Early mediastinal spread — Central location allows rapid invasion of mediastinal lymph nodes (present in ~90% at diagnosis).
3.
Clinical presentation — Hemoptysis, airway obstruction, and superior vena cava syndrome are common.
High-YieldNEET PG
SCLC is a centrally located, hilar/mediastinal mass in a heavy smoker — this is the classic presentation. Peripheral lung nodules should raise suspicion for adenocarcinoma or squamous cell carcinoma, not SCLC.
Clinical Pearl
The central location of SCLC explains why it is almost always unresectable at presentation — mediastinal involvement precludes surgical cure in the majority of cases.
Warning
Do not confuse SCLC (central, neuroendocrine) with adenocarcinoma (peripheral, mucous gland origin). The site of origin is a key differentiator.
Robbins 10e Ch 15
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