Small colorectal cancers resembling submucosal tumor with massive submucosal invasion and lymph node metastasis: A report of two cases and review of the literature.
Colorectal cancer resembling submucosal tumor (SMT) is very rare. We herein report two cases of small colon carcinoma resembling SMT (80-year-old female and 67-year-old male), which massively invaded into the submucosal layer and accompanied marked lymphatic invasion and lymph node metastasis. We also reviewed the reported cases of colorectal carcinoma resembling SMT (SMT-like group, n=70) and analyzed the clinicopathological characteristics of this group compared with typical colorectal carcinoma cases operated at our institution (control group, n=1723). Tumors in the SMT-like group were significantly smaller in size compared with the control group; the median diameter measured 22mm vs. 37mm (P<0.01), respectively. Histologically, although the tumors in the SMT-like group were small in diameter, they almost all invaded into the submucosal (T1) or deeper layer (T2-4), and the rate of poorly differentiated adenocarcinoma or mucinous adenocarcinoma was significantly higher than that in the control group (48.6% vs. 7.7%; P<0.01). In the subgroup analysis of T1 tumors, the rate of lymphatic invasion in the SMT-like group was also significantly higher than that in the control group (43.8% vs. 15.4%; P<0.01). Carcinoma resembling SMT appears to be invasive and has a high risk of lymphatic invasion even if small in size. Therefore, surgical treatment with dissection of the regional lymph nodes might be necessary in cases with any signs of massive submucosal invasion.
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan. Electronic address: takahide124@gmail.com.
Takahide
T
Shinagawa
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Soichiro
S
Ishihara
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Hiroaki
H
Nozawa
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Koji
K
Murono
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Takeshi
T
Nishikawa
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Kensuke
K
Otani
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Kazuhito
K
Sasaki
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Koji
K
Yasuda
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Toshiaki
T
Tanaka
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Tomomichi
T
Kiyomatsu
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Keisuke
K
Hata
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Kazushige
K
Kawai
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Hironori
H
Yamaguchi
Department of Pathology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Akimasa
A
Hayashi
Department of Pathology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Mariko
M
Tanaka
Department of Pathology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Tetsuo
T
Ushiku
Department of Pathology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Masashi
M
Fukayama
Department of Surgical Oncology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, 113-8655 Tokyo, Japan.
Toshiaki
T
Watanabe
D000230:Adenocarcinoma / Q000473:pathology; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000473:pathology* / Q000601:surgery; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology*; D010535:Laparoscopy; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology*