High-Grade Neuroendocrine Carcinoma with Bronchial Intraepithelial Tumor Spread: Possibly a New Histologic Feature of Large-Cell Neuroendocrine Carcinoma.
BACKGROUND
During surgical resection of a peripherally located high-grade neuroendocrine carcinoma (HGNEC), we unexpectedly discovered prominent bronchial intraepithelial tumor spread up to the surgical end of the bronchus. Because bronchial intraepithelial tumor spread of peripherally located HGNEC has been rarely reported, we conducted a retrospective analysis at our hospital.


METHODS
We histologically reviewed surgically resected HGNEC cases to assess bronchial intraepithelial spread of tumor cells. HGNECs with bronchial intraepithelial tumor spread were further studied by immunohistochemistry for neuroendocrine markers, and their clinicopathological characteristics were evaluated.


RESULTS
Of 1778 cases of surgically resected lung cancer in our hospital, 47 cases of HGNEC were evaluated. Bronchial intraepithelial tumor spread was observed in nine cases (19.1%); eight of these cases were large-cell neuroendocrine carcinoma (LCNEC) or small-cell lung carcinoma with an LCNEC component. Moreover, bronchial intraepithelial tumor spread was continuous from the primary tumor to the resected end of the bronchus in four cases, and all these cases had an LCNEC component. Furthermore, HGNEC with bronchial intraepithelial tumor spread was associated with a higher recurrence rate than no bronchial intraepithelial tumor spread.


CONCLUSIONS
The results of this study suggest that bronchial intraepithelial tumor spread is commonly observed in cases of peripherally located HGNEC and may be a unique form of tumor invasion, especially tumors with LCNEC morphology. Therefore, surgeons and pathologists should be cognizant of bronchial intraepithelial tumor spread in peripherally located HGNEC, as well as its potential role as an indicator of HGNEC aggressiveness.
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan. Electronic address: h.kojima@scchr.jp.
Hideaki
H
Kojima
Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
Reiko
R
Watanabe
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Mitsuhiro
M
Isaka
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Reiko
R
Shimizu
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Hiroyuki
H
Kayata
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Naoko
N
Miyata
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Tomohiro
T
Maniwa
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Shoji
S
Takahashi
Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
Ichiro
I
Ito
Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
Toru
T
Kameya
First Department of Surgery, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Kazuhito
K
Funai
Division of Thoracic Surgery, Shizuoka Cancer Center, Shizuoka, Japan.
Yasuhisa
Y
Ohde
Division of Pathology, Shizuoka Cancer Center, Shizuoka, Japan.
Takashi
T
Nakajima
D000368:Aged; D000369:Aged, 80 and over; D001984:Bronchial Neoplasms / Q000473:pathology*; D018287:Carcinoma, Large Cell / Q000473:pathology*; D018278:Carcinoma, Neuroendocrine / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading