Fatal submucosal invasive gastric adenosquamous carcinoma detected at surveillance after gastric endoscopic submucosal dissection

Abstract

An 80-year-old man was under annual surveillance esophagogastroduodenoscopy after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC). Two years after the initial ESD, a 0-IIc type metachronous EGC lesion, 8 mm in size, without an ulcer scar, was found in the gastric antrum. The estimated tumor depth was up to the mucosa, and biopsy revealed well and poorly differentiated adenocarcinoma. ESD was performed for this lesion and en bloc resection with negative margins was achieved. Histopathological examination revealed an adenosquamous carcinoma 8 mm in size invading the deep submucosal layer (1600 μm), with lymphovascular invasion, consistent with the diagnosis of non-curative resection. Additional gastrectomy was recommended for this patient; however, two months after the ESD, preoperative computed tomography revealed multiple liver metastases, and the patient was considered as an unsuitable candidate for surgical resection. Systemic chemotherapy was therefore started; however, the patient died of gastric cancer 27 mo after the second ESD. Early gastric adenosquamous carcinoma localized to the mucosa and submucosa is extremely rare and its clinical behavior is not well known. The present report is very significant in that it underscores the distinct possibility of gastric adenosquamous carcinoma being very aggressive and fatal even when detected at an early cancer.

Clinicopathological features and prognosis of gastric adenosquamous carcinoma

“…The histogenesis of gastric ASC was still under debate. Several hypotheses have been proposed: 5 (1) squamous metaplastic transformation of AC, (2) oncogenic transformation of ectopic squamous epithelium, (3) oncogenic transformation of metaplastic squamous cells, (4) collision of concurrent AC and SCC, (5) differentiation of stem cells toward both glandular and squamous cells. The first hypothesis was supported by many researchers based on accumulating evidence.…”

Gastric squamous cell carcinoma and gastric adenosquamous carcinoma, clinical features and outcomes of rare clinical entities: a National Cancer Database (NCDB) analysis

“…Diagnosis of GASC requires coexistence of both adenocarcinoma and squamous cell carcinoma in the primary tumor and squamous component should exceed 25% of the primary tumor (12,13). Several hypotheses have been proposed for pathogenesis of GASC so far including squamous metaplastic transformation of adenocarcinoma; transformation of ectopic squamous epithelium or transformation of metaplastic squamous cells; collision of concurrent AC and SCC (5), or stem cells differentiation toward both glandular and squamous cells (7,14).…”

A Primary Adenosquamous Carcinoma of the Stomach: Report of Two Cases

“…Adjuvant chemotherapy was administered because both cases were stage III. However, a standard chemotherapy protocol for adenosquamous stomach carcinomas remains undefined (2,8). Thus, oral capecitabineintravenous infusion with cisplatin chemotherapy was administered considering the age and general condition of the patients.…”