Simultaneous gastric adenosquamous carcinoma and gastric carcinoma with lymphoid stroma: A case report

Abstract

Primary gastric adenosquamous carcinoma (ASC) is a rare tumor, and gastric carcinoma with lymphoid stroma (GCLS) is a distinct and relatively rare tumor, which is characterized histopathologically by prominent lymphoid infiltration and is commonly associated with Epstein-Barr virus (EBV) infection. The association between ASC and GCLS has been poorly understood, and only two cases of concomitant occurrence of ASC and GCLS have been reported previously. In this report, we describe the first documented case of simultaneous gastric ASC and GCLS. A 58-year-old Japanese male complained of loss of appetite. Gastric endoscopic examination revealed a type 3 tumor in the antrum. Distal gastrectomy with lymph node dissection was performed after neoadjuvant chemotherapy. Macroscopic examination of the resected specimen revealed two discontinuous lesions in the antrum. The first lesion, an ASC, was detected preoperatively by endoscopic examination. This type 3 tumor was composed of a mixture of squamous cell carcinoma (~75% of the tumor) and poorly-to-moderately differentiated adenocarcinoma (~25%). No EBV-encoded RNA (EBER)-positive neoplastic cells were noted. The tumor had invaded into the serosa. The second lesion was a GCLS, which was not preoperatively detected by endoscopic examination. The neoplastic cells of the GCLS were EBER-positive. The tumor had invaded into the muscularis propria. Accordingly, a diagnosis of simultaneous gastric ASC (pT4a) and GCLS (pT2) was made. The pathogenesis of gastric ASC has been under debate. Only limited cases of ASC associated with EBV have been reported. Notably, EBV has not been associated with the development of an ASC component in the previously reported concomitant cases of ASC and GCLS, as well as in the present case study. Therefore, additional studies are required to clarify the pathogenesis of gastric ASC, including its association with EBV.

Epstein–Barr virus-associated gastric adenosquamous carcinoma with concurrent gastric carcinoma with lymphoid stroma: a case report and review of the literature

“…There are several hypotheses proposed: (i) collision of concurrent AC and SCC, (ii) originating from the same cancer stem cell, which can differentiate into AC and SCC, (iii) oncogenic transformation of metaplastic squamous cells, (iv) squamous metaplastic transformation from the existing AC or GCLS. Considering that there was a transition between AC and SCC in the present case, and AC was the most frequent component in the metastatic lymph nodes with gastric ASC as indicated in the literature and also in our case [ 6 , 7 ], we suggest the last possibility.…”

Case report: Gastric adenosquamous carcinoma with EBV-positive component of squamous cell carcinoma mixed with gastric carcinoma with lymphoid stroma: A novel case report and literature review

“…Lymph node metastases from all three components were observed, with AC being the most common component. In the reported cases, EBER staining was only positive in the GCLS region in three cases ( 1 - 3 ), while it was throughout positive in one case ( 4 ). In the Ji-Hoon’s report ( 5 ), EBER staining was diffusely positive in GCLS and focally positive in SCC.…”

“…A mixture of AC and SCC can be seen in four cases, and even a transition of AC and SCC has been observed ( 4 ). In addition, AC is the most common component of the metastatic lymph nodes of patients with gastric ASC ( 3 , 4 , 13 ). In the present case, considering the presence of a transition area between AC and the other two components with EBER positive expression, we suggest the second possibility.…”

Increased proportion of the squamous cell carcinoma component is associated with worse survival in resected gastric adenosquamous carcinoma

“…Although numerous discussions have occurred in previous articles, [ 5 , 7 , 8 , 19 , 22 , 23 ] the pathogenesis of the SCC component in gastric cancer remains obscure since the first report of this scarce disease in 1905 by Rolleston and Trevor. [ 24 ] The most convincing hypothesis regarding the pathogenesis of the SCC component is squamous metaplasia of a preexisting AC, which is widely accepted by most authors.…”