Special manifestations of colon cancer

Colon cancer can penetrate the intestinal wall and communicate with the abdominal cavity, forming a perforation, or it can communicate with other internal organs to form a fistula. When a fistula is formed with the stomach, feces may be vomited, and when it is connected with the small intestine, it can be detected by X-ray. In some cases, the tumor penetrates the abdominal wall and communicates with the outside of the body.

Carcinoid syndrome caused by carcinoid tumor

Carcinoid tumors are common in the appendix and rectum. They originate from Lieberkuhn alveolar Kulchitsky cells. Due to the secretion of 5-hydroxylamine, bradykinin, histamine, and catecholamines, some carcinoid tumors may cause carcinoid syndrome, which is manifested by skin flushing, diarrhea, asthma, cyanosis, dyspnea, interphalangeal joint pain, mental disorders, and endocardial fibrosis. Patients with common colon tumor symptoms such as blood in the stool and abdominal tumors accompanied by carcinoid syndrome should first consider the possibility of colon carcinoid tumors.

Acute appendicitis as the first sign

The coexistence of colon cancer and acute appendicitis is not uncommon in clinical practice. Ambjomsson et al. reported 561 patients aged 40 years or older who underwent appendectomy for acute appendicitis. Among them, 16 patients came back for colon cancer within 3 years after surgery, accounting for 2.9%.

The causes of colorectal cancer coexisting with acute appendicitis include:

① Colon tumors cause obstruction of the appendix root lumen;

② Tumor growth leads to obstruction of appendix lymph or blood flow;

③ Intestinal obstruction increases the intraluminal pressure, affecting the normal drainage of the appendix;

④ The spread of inflammation in the area surrounding the tumor causes appendicitis. It is not uncommon for acute appendicitis to be the first symptom of colon cancer. Therefore, the possibility of colon cancer should be considered for patients with acute appendicitis accompanied by changes in stool characteristics and habits and chronic abdominal pain. When performing appendectomy due to appendicitis, attention should be paid to colon exploration. Patients with appendicitis over 40 years old should pay special attention to excluding colon cancer.