Early colonic carcinoma with extensive lymph node metastases: case report and review of literature

Small, Depressed-Type Early Colon Cancer Invading Shallow Submucosal Layer With Extensive Lymph Node Metastasis: A Case Report

Early colorectal cancers are defined as invasive tumors that are limited to the mucosal layer or submucosal layer (SM), regardless of the presence or absence of lymph node (LN) metastasis. The reported incidence of LN metastasis of SM1 colon cancers is 0 - 5.9%, but the incidence in SM2 and SM3 colon cancers could be as high as 11.3 - 25.0%, and risk factors for LN metastasis include depth of SM invasion, growth patterns (polypoid or non-polypoid), histological sub-classification (moderate or poor differentiation) and regional lymphatic and vascular invasion. Among colorectal cancers with non-polypoid growth, the malignant potential is higher for depressed, than polypoid types, even for small tumors. Herein, we describe a patient with small, depressed-type early colon cancer with extensive LN metastasis and superficial SM invasion (pSM 450 µm). Six courses of chemotherapy with mFOLFOX6 and bevacizumab reduced the size of the LN metastases, thus eliciting a partial response (PR) according to the response evaluation criteria in solid tumors (RECIST).

Optimum lymph node dissection in clinical T1 and clinical T2 colorectal cancer

PURPOSE

On the basis of a retrospective review, we aimed to clarify the optimum extent of lymph node dissection in patients with cT1 and cT2 colorectal cancer.

METHODS

We reviewed medical records of 487 patients with cT1 and 351 patients with cT2 colorectal tumors, who had undergone curative surgery.

RESULTS

In patients with cT1 tumors, results of pathologic examination showed either no lymph node metastasis or metastasis within the paracolic or pararectal region in 284 (98.3 percent) of 289 patients with colon tumors and 195 (98.5 percent) of 198 with rectal tumors. Of 459 patients without clinically evident metastasis, only one patient with a poorly differentiated adenocarcinoma had metastasis beyond the paracolic area. In 28 patients with cT1 tumors and clinically diagnosed node metastasis, pathologic examination showed that node involvement did not extend beyond the named vessel in 26. Among patients with cT2tumors, 97.5 percent of patients with colon tumors and 95.9 percent with rectal tumors had no or limited metastasis. Of 276 without clinically evident metastasis, none had node metastasis at the roots of the named vessels; of 75 with clinically evident metastasis, none had pathologic extension beyond the roots of the named vessels.

CONCLUSIONS

In cT1 patients with cN-negative colorectal cancers, paracolorectal lymph node dissection may be optimal; in those with cN positivity, the regional nodes along the named vessels should be dissected. In cT2 patients who are cN-negative, dissection of the regional nodes may be optimal. For those with cN positivity, dissection at the roots of the named vessels should be considered.