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.

Intraductal US is a useful adjunct to ERCP for distinguishing malignant from benign biliary strictures.

BACKGROUND: Distinguishing malignant from benign biliary strictures remains a challenge. This prospective study assessed intraductal US as an adjunct to endoscopic retrograde cholangiography and tissue sampling for diagnosis of malignant and benign biliary strictures. METHODS: Sixty-two patients were enrolled who had biliary strictures suspected to be malignant but with negative tissue sampling by endoscopic retrograde cholangiography, or suspected biliary strictures based on clinical manifestations and/or cross-sectional imaging. Intraductal US was performed with an over-the-wire 2.4-mm diameter 20 MHz catheter US probe. The diagnostic accuracy of endoscopic retrograde cholangiography plus tissue sampling with and without intraductal US was compared with surgical findings or clinical outcome at a 12-month follow-up (benign/malignant) in nonsurgical cases. Tissue sampling results were reported as malignant, suspicious for malignancy, atypical, or normal. Analysis was by intention-to-treat. RESULTS: Two patients (3%) were excluded from analysis because the stricture could not be traversed with the intraductal US probe. Of the 60 remaining patients (37 men, mean age 64 years, range 27-89 years), 31 had malignant strictures (12 cholangiocarcinoma, 8 pancreatic, 5 metastatic, 3 gallbladder, 3 papilla), and 29 had benign strictures. Sphincterotomy was not required in any case to facilitate intraductal US. Fourteen patients (23%) underwent subsequent surgery including 11 with a preoperative diagnosis of resectable tumor. Endoscopic retrograde cholangiography/tissue sampling (atypia considered equivalent to benign) correctly identified 15 of 31 malignant strictures (p = 0.001) and all 29 benign strictures (p = 0.16) (accuracy 73%, sensitivity 48%, specificity 100%). The addition of intraductal US correctly identified 28 of 31 malignant strictures and 27 of 29 benign strictures (accuracy 92%, sensitivity 90%, specificity 93%). Of 11 patients with tumors who came to surgery, intraductal US correctly staged 4 (36%), understaged 5 (45%), missing metastatic lymph nodes in all cases and vascular invasion in 1 patient, and overstaged 2 (18%), with a false-positive diagnosis of metastatic lymph nodes in 1 and tumor mass in 1 patient who had no cancer at surgery. CONCLUSION: Technically easy, intraductal US is a valuable adjunct to endoscopic retrograde cholangiography/tissue sampling that increases the ability to distinguish malignant from benign strictures. Intraductal US is unsuitable for assessing lymph nodes associated with malignant strictures.