Primary Squamous Cell Carcinoma of the Stomach: A Case Report and Review of the Literature.

Primary gastric squamous cell carcinoma (PGSCC) is an exceedingly rare disease, accounting for 0.04% - 0.07% of all gastric cancers. First reported in 1895 by Rörig et al, less than 100 cases of PGSCC worldwide have been reported in the literature. These reports show PGSCC is more common in males (5:1 male to female ratio), and exhibits a peak incidence in the sixth decade of life. It may involve any portion of the stomach with predilection for the proximal stomach, especially along the lesser curvature. Although no clear pathogenesis of this tumor has been reported, several plausible theories have been proposed. These include squamous differentiation of preexisting gastric adenocarcinoma, cancerization of ectopic squamous epithelium, malignant transformation of squamous metaplasia of glandular epithelium, association with Helicobacter pylori or Epstein-Barr virus infection, and evolution in the setting of marked chronic gastritis with intestinal metaplasia. This report presents and discusses the case of a 64-year-old female who developed PGSCC arising in the gastric fundus.