1. Pulmonary large cell carcinomas with neuroendocrine features are high-grade neuroendocrine tumors 
Akira Iyoda, MD, Kenzo Hiroshima, MD, Masayuki Baba, MD, Yukio Saitoh, MD, Hidemi Ohwada, MD, Takehiko Fujisawa, MD 
The Annals of Thoracic Surgery 
Volume 73, Issue 4, Pages (April 2002)
DOI: /S (01)

2. Fig 1
Histological features of typical carcinoid. Light microscopy (hematoxylin and eosin stain, ×40). The tumor cells reveal growth patterns such as organoid, palisading, or rosette-like arrangements, which suggest neuroendocrine differentiation. These tumor cells have uniform cytologic features with eosinophilic, finely granular cytoplasm and nuclei with a finely granular chromatin pattern. Typical carcinoids have less than two mitoses per 2 mm2 and lack necrosis.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

3. Fig 2
Histological features of atypical carcinoid. Light microscopy (hematoxylin and eosin stain, ×40). The tumor cells reveal growth patterns such as typical carcinoid. However, atypical carcinoids have 2 to 10 mitoses per 2 mm2 and/or necrosis.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

4. Fig 3
Histological features of large cell neuroendocrine carcinoma. Light microscopy (hemotoxylin and eosin stain, ×40). The tumor cells have a neuroendocrine morphology with organoid nesting, palisading, and rosettes. Numerous mitoses, which are 11 or greater per 2 mm2, are seen. Cytologic features include large cell size, low nuclear-to-cytoplasmic ratio, fine chromatin, and nucleoli.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

5. Fig 4
Histological features of large cell neuroendocrine carcinoma. Immunohistochemistry (×40). The tumor cells stain positive with a polyclonal anti-chromogranin A antibody.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

6. Fig 5
Histological features of small cell carcinoma. Light microscopy (hematoxylin and eosin stain, ×40). The tumors consist of small cells, which are round, oval, and spindle-shaped, and generally less than the diameter of three small resting lymphocytes, with scant cytoplasm, ill-defined cell borders, finely granular nuclear chromatin, and absent or inconspicuous nucleoli.
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

7. Fig 6
The overall survival curves for each tumor histological type. The overall survival for patients with atypical carcinoid was significantly higher than for those with large cell carcinoma with neuroendocrine features (p < 0.001) and with small cell lung carcinoma (p < 0.001). (AC = atypical carcinoid; LCNF = large cell carcinoma with neuroendocrine features; SCLC = small cell lung carcinoma; TC = typical carcinoid.)
The Annals of Thoracic Surgery  , DOI: ( /S (01) )

8. Fig 7
The disease-free survival curves for each tumor histological type. The disease-free survival for patients with atypical carcinoid was significantly higher than for those with large cell carcinoma with neuroendocrine features (p < 0.001) and small cell lung carcinoma (p < 0.001). (AC = atypical carcinoid; LCNF = large cell carcinoma with neuroendocrine features; SCLC = small cell lung carcinoma; TC = typical carcinoid.)
The Annals of Thoracic Surgery  , DOI: ( /S (01) )