A case report of adenosquamous carcinoma of the esophagogastric junction

Abstract

Background: Many types of tumors can arise in the esophagogastric junction (EGJ). Squamous cell carcinoma (SCC) arising from the esophageal epithelia, adenocarcinoma arising from the gastric mucosa, or Barrett's esophageal mucosa are frequently observed in the EGJ. However, adenosquamous carcinoma (ASC) has been rarely observed in this area. We herein report a rare case of ASC of the EGJ.

Case presentation: An 81-year-old man visited our hospital complaining of dysphagia. Esophagogastroduodenoscopy detected an elevated tumor in the gastric cardia. Biopsy specimens taken from the tumor showed SCC. Computed tomography revealed a tumor located in the EGJ and node metastases surrounding the EGJ. The tumor was diagnosed as SCC, overhanging in the stomach, of the EGJ. The patient underwent a proximal gastrectomy with a lower esophagectomy and node dissection for the metastases surrounding the EGJ, and esophagogastrostomy in the lower mediastinum. Histopathologic examination showed the tumor consisted of SCC and adenocarcinoma. The adenocarcinoma consisted of nests scattered in the SCC. We observed adenocarcinoma component in 35% of the tumor and epithelial spread of SCC in the lower esophagus. Thus, we diagnosed the tumor as ASC of the EGJ. Eight metastatic nodes were dissected; both SCC and adenocarcinoma were observed in seven.

Conclusions: In the present case, SCC may be originated from the squamous epithelia of the lower esophagus and grew into the stomach, and the adenocarcinoma may have differentiated from SCC through the infiltration.

Keywords: Adenosquamous carcinoma; Esophagogastric junction; Submucosal tumor-like.

Fig. 1

Esophagogastroduodenoscopy findings. A An elevated lesion is found in the EGJ. The tumor is easy to bleed, and its demarcation is ill-defined because of submucosal invasion. B The tumor overhangs in the gastric cardia, but continues into the squamocolumnar junction (arrow). C In the lower esophagus, the tumor invades in the esophageal submucosa (arrowheads). The lumen of the EGJ is intact

Fig. 2

Findings of barium meal study. A An elevated lesion is detected in the gastric cardia (arrowheads). B The tumor invades the lower esophagus approximately 15 mm from the EGJ with stenosis (arrow)

Fig. 3

Image findings. A Computed tomography. Computed tomography reveals a mass, 50 mm in diameter, in the EGJ (arrow). B ¹⁸F-FDG-positron emission tomography. In 18F-FDG-positron emission tomography, SUV max of FDG accumulation is 19.9 in the tumor (arrow)

Fig. 4

Macroscopic findings. A Macroscopic findings of the resected specimen. An elevated tumor is mainly located in the gastric cardia. B The cut surface of the tumor. The tumor is covered with the normal squamous mucosa (arrowheads) and the gastric mucosa (arrows). C A schema of the cut surface. Black areas show the adenocarcinoma components, while diagonal area shows the SCC components. The adenocarcinoma component is located diffusely as a focal area in the tumor and occupies 35% of the tumor, while the SCC component is located in the surface to the deep layer of the tumor.

Fig. 5

Histopathologic findings. A Low-power magnification of SCC in hematoxylin and eosin staining (HE). SCC, covered with the normal squamous epithelium, is infiltrated diffusely in the tumor (arrows). B High-power magnification of SCC (HE). SCC is moderately differentiated. C Low-power magnification of adenocarcinoma (HE). Scattered adenocarcinoma nests are observed in the tumor. D High-power magnification of adenocarcinoma (HE). Adenocarcinoma is well-differentiated. E AB-PAS staining shows blue adenocarcinoma cells. F Superficial SCC in the squamous epithelium of the lower esophagus. G Distal part of SCC is covered with the normal columnar epithelium (arrowheads). H Several transition parts between SCC and adenocarcinoma components are observed in the primary tumor. The left panel shows SCC (left side on the dashed line) and the right panel shows the adenocarcinoma component (right side on the dashed line). I The SCC component is observed in the No. 11p nodes dissected. J The adenocarcinoma component is observed in the No. 11p nodes synchronously. K No reaction for HER2 is immunohistochemically observed in SCC cells. L A positive reaction for HER2 is observed in adenocarcinoma cells, the staining intensity is judged to be 2+