Low-grade dysplasia component in early invasive squamous cell carcinoma of the esophagus.
OBJECTIVE
It has not been determined whether low-grade squamous dysplasia (LGD) of the esophagus is a precancerous lesion or not. If LGD progresses to squamous cell carcinoma, early carcinoma lesions that have such a natural history might contain a remaining LGD component.


METHODS
The lesions in the 68 patients with early invasive squamous cell carcinoma who underwent endoscopic mucosal resection were examined for the presence of an LGD component. If LGD components were observed, the degrees of architectural and cytological abnormalities of LGD components and those of tumor invasive fronts in the same lesions were studied. The degrees of abnormalities of 28 small LGD lesions were also studied.


RESULTS
Histological examination of resected specimens confirmed LGD components in 43% of the squamous cell carcinoma lesions. The lesions of lamina propria mucosae (m2) cancer contained a significantly broader area of LGD component than did the lesions of muscularis mucosae (m3) and submucosal layer (sm) cancer (P = 0.037). Mean score for the degrees of cytological abnormalities of LGD component was similar to that of tumor invasive front (P = 0.457) and significantly higher than that of small LGD lesions (P < 0.001).


CONCLUSIONS
Our results indicate the possibility that the lesion was formed by a combination of small lesions that arose as a multicentric occurrence of squamous cell carcinoma and dysplasia. Our results also suggest that an LGD component would transform to carcinoma along with tumor progression. However, the concept of 'basal cell layer type carcinoma in situ' may be suitable for squamous cell lesions with a high degree of cytological abnormalities confined to the lower half of the epithelium.
Shimizu
Yuichi
Y
Department of Gastroenterology, Hokkaido University Graduate School of Medicine, Sapporo, Japan. yshimizu@med.hokudai.ac.jp
Yoshida
Takeshi
T
Kato
Mototsugu
M
Hirota
Jojo
J
Ono
Shouko
S
Nakagawa
Manabu
M
Kobayashi
Takahiko
T
Kubota
Kanako
K
Asaka
Masahiro
M
D000230:Adenocarcinoma / Q000473:pathology*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002278:Carcinoma in Situ / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000473:pathology*; D004945:Esophagoscopy; D004947:Esophagus / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D011230:Precancerous Conditions / Q000473:pathology*