'Head Invasion' Is Not a Metastasis-Free Condition in Pedunculated T1 Colorectal Carcinomas Based on the Precise Histopathological Assessment.
OBJECTIVE
Previous reports stated that pedunculated T1 colorectal carcinomas with 'head invasion' showed almost no nodal metastasis, requiring endoscopic treatment alone. However, clinically, some lesions develop nodal metastasis. We aimed to validate the necessity of distinguishing between 'pedunculated' and 'non-pedunculated' lesions, and also between 'head' and 'stalk' invasions.


METHODS
Initial or additional surgery with lymph node dissection was performed in 76 pedunculated and 594 non-pedunculated cases. Among pedunculated lesions, the baseline was defined as the junction line between normal and neoplastic epithelium (Haggitt's level 2). The degree of invasion was classified as 'head invasion' (above the baseline) or 'stalk invasion' (beyond the baseline). Clinicopathological factors were analyzed with respect to nodal metastasis.


RESULTS
Nine of 76 (11.8%) pedunculated cases and 52/594 (8.8%) non-pedunculated cases developed nodal metastasis (p = 0.40). No significant differences were found in the rate of nodal metastasis between 'head invasion' (4/30, 13.3%) and 'stalk invasion' (5/46, 10.9%). All the 4 cases with 'head invasion' had at least one pathological factor.


CONCLUSIONS
'Head invasion' was not a metastasis-free condition. Even for pedunculated T1 cancers with 'head invasion', additional surgery with lymph node dissection should be considered if these have pathological risk factors.
Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan.
Yui Jennifer
YJ
Kimura
Shin-Ei
SE
Kudo
Hideyuki
H
Miyachi
Katsuro
K
Ichimasa
Yuta
Y
Kouyama
Masashi
M
Misawa
Yuta
Y
Sato
Shingo
S
Matsudaira
Hiromasa
H
Oikawa
Tomokazu
T
Hisayuki
Yuichi
Y
Mori
Toyoki
T
Kudo
Noriyuki
N
Ogata
Kenta
K
Kodama
Kunihiko
K
Wakamura
Takemasa
T
Hayashi
Atsushi
A
Katagiri
Toshiyuki
T
Baba
Eiji
E
Hidaka
Fumio
F
Ishida
Shigeharu
S
Hamatani
D000230:Adenocarcinoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D004724:Endoscopy; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology* / Q000601:surgery; D007564:Japan; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012307:Risk Factors