Clinicopathologic characteristics of early-stage mucinous gastric carcinoma

Early mucinous gastric carcinoma (MGC) is very rare, and the clinicopathologic features are not well understood. The aim of this study is to clarify the clinicopathologic characteristics of early MGC.

A total of 806 patients with gastric cancer underwent gastrectomy between 1983 and 2002 at our department. Of these patients, 7 were found to have early MGC. MGC was defined as a tumor in which more than 50% of the tumor area contained extracellular mucin pools. Microscopic examination was performed, and particular attention was paid to the mucin component of the tumor and histologic subtype (ie, well-differentiated or poorly-differentiated).

The incidence of early MGC among all gastric carcinomas in our series was 0.9% (7/806). Tumors ranged in size from 1.0 cm to 7.2 cm, with a mean of 3.7 cm, and 4 appeared macroscopically elevated and 3 appeared depressed. Histologically, 3 tumors were considered well-differentiated type and 4 were considered poorly differentiated type. Microscopic features were thickening of the submucosal layer due to accumulation of abundant mucin and elevation of the surrounding normal mucosa. Tumor invaded the submucosa in 6 cases, and lymph node metastasis occurred in 1 case. However, no patient died of recurrence during follow-up periods ranging from 4 to 85 months.

Early MGC is characterized as an elevated lesion resembling submucosal tumor due to abundant mucin pools in the submucosa. Cases of early MGC have a good outcome similar to that of early non-MGC.