Malignant tumors, such as breast cancer, lung cancer, renal cell carcinoma, malignant melanoma, can metastasize to the stomach . However, metastasis to the stomach is uncommon, especially that originates from colon cancers. According to the report of Terashima et al. , there were 14 GM cases originating from colon cancer in 2019 in the Fukushima Journal of Medical Science.
The clinical symptoms of GM are non-specific , including dyspepsia, anorexia, abdominal distension, black stool, nausea, vomiting, upper abdominal pain, early satiety, and bleeding, and even gastric perforation [10-12]. However, the most common symptom is abdominal pain. Our patient presented with a 6-month history of abdominaldistension and anal pendant expansion, which may be caused by colon cancer.
GM can occur anywhere in the stomach, but mainly in the upper two-thirds of the stomach. They can be single or multiple and synchronous or metachronous, while they are mainly single and metachronous . Our patient had single synchronous stomach metastasis.
There are four types of GM . The first type comprises polypoid lesions, a nodule or mass, which is easily confused with gastric polyps. The second type is ulcerative mass, which is the typical imaging feature of GM. This mass is mainly in the submucosa of the stomach, manifesting as local gastric wall thickening with ulceration at the top of the lesion and normal adjacent or surface mucosa. This is described as a “bull’s-eye sign” or “crateriform ulcer” on gastrointestinal endoscopy . It is easily confused with gastric stromal tumors. The third type involves a submucosal nodule in the gastric wall . It is easily confused with gastric stromal tumors, neurinoma, and liomyoma. The final type is diffuse gastric wall thickening, also called “linitis plastica” , which is prone to be confused with diffuse gastric cancer. Except for the diffuse gastric wall thickening type, the mucosa and adjacent gastric wall of the other GM types usually appear normal, without enlarged lymph nodes around the stomach. GM may occur alone or in association with other metastatic sites such as the lung, liver, brain, and adrenal glands, and the latter is more common.The current case belongs to the first type and has a polypoid mass with homogeneous enhancement.
Metastasis to the gastric wall occurs in several ways, such as direct invasion, hematogenous metastasis, lymphatic metastasis and intraoperative implantation . Among them, hematogenous and lymphatic metastases are the most common. In our case, GM occurred through hematogenous metastasis.
Current treatment methods for GM include surgical resection, neoadjuvant chemoradiotherapy, endoscopic electrocoagulation, and endoscopic resection . Because of rapid metastatic tumor growth, the survival time of GM patients is only a few months after primary diagnosis . However, with appropriate treatment, patients can live longer. By combining surgery with chemotherapy and radiotherapy, the longest survival time is seven years . So far, our patient recovers well, 18 months after surgery, with 13 times of chemotherapy.
This report presents a rare case of synchronous isolated GM from ascending colon carcinoma. In this case, polypoid lesion in the gastric wall has certain imaging characteristics feature of GM on CT. This case study also demonstrates that surgery combined with chemotherapy may promote prognosis in patients with synchronous isolated GM.