Mixed adenoneuroendocrine carcinoma of gastrointestinal tract: Report of two cases

Mixed adenoneuroendocrine carcinoma(MANEC) is a rare tumor of the gastrointestinal tract that consists of a dual adenocarcinomatous and neuroendocrine differentiation, each component representing at least 30% of the tumor. To date, only seven cases have been reported in the cecum, and less than 40 in the stomach. Our first case was diagnosed in a 74-years-old female as a polypoid lesion of the cecum with direct invasion in the transverse colon, without lymph node metastases. The second case was diagnosed in the stomach of a 46-years-old male as a polypoid tumor of the antral region that invaded the pancreas and presented metastases in 22 regional lymph nodes. The metastatic tissue was represented by the glandular component. In both cases, the tumor consisted of a moderately-differentiated tubular adenocarcinoma(with mucinous component in Case 1) intermingled with neuroendocrine carcinoma. Ki67 index was lower than 20% in Case 1, respectively higher than 20% in Case 2. The neuroendocrine component was marked by synaptophysin and neuron specific enolase, being negative for Keratins 7/20. The neuroendocrine component represented 60% in Case 1, and 40% in Case 2, respectively. The glandular components were marked by carcinoembryonic antigen, maspin and keratin 20/7(Case 1/2). Both cases were proved to be microsatellite stable. Independently by the localization and tumor stage, MANECs appear to be highly malignant tumors, with high risk for distant metastases. The aggressiveness seems to depend on the endocrine component, independent of its proportion. The neuroendocrine component could be a dedifferentiated adenocarcinoma with a neuroendocrine phenotype.

Single skip metastasis in sentinel lymph node: In an early gastric cancer

Lymph node status is considered a key prognostic and predictive factor in patients with gastric cancer(GC).Although there is a practical approach to the intraoperative detection of sentinel lymph nodes(SLNs),such a procedure is not included in the European surgical protocol.In this report,we present a practical approach to SLN mapping in a representative case with early gastric cancer(EGC).A 74-year-old female was hospitalized with an endoscopically observed,superficially ulcerated tumor located in the antral region.Subtotal gastrectomy with D2 lymphadenectomy and SLN mapping was performed by injecting methylene blue dye into the peritumoral submucosal layer.An incidentally detected blue-stained lymph node located along the middle colic artery was also removed.This was detected 40 min after injection of the methylene blue.Histopathologic examination showed a p T1b-staged well-differentiated HER-2-negative adenocarcinoma.All of the 41 LNs located at the first,third,and fifth station of the regional LN compartments were found to be free of tumor cells.The only lymph node with metastasis was located along the middle colicartery and was considered a non-regional lymph node.This incidentally identified skip metastasis indicated stage Ⅳ GC.A classic chemotherapy regimen was given,and no recurrences were observed six months after surgery.In this representative case,low-cost SLN mapping,with a longer intraoperative waiting time,totally changed the stage of the tumor in a patient with EGC.

Cystic jejunal duplication with Heinrich's type Ⅰ ectopic pancreas, incidentally discovered in a patient with pancreatic tail neoplasm

The aim of this study was to present a case of enteric duplication cyst and criteria for a proper differential diagnosis. A 51-year-old male was hospitalized for pancreatic tail neoplasm and distal pancreatectomy with splenectomy was performed. During surgery, a jejunal cystic lesion was incidentally detected and jejunectomy was performed. Microscopically, the cyst was observed to be covered by Keratin 7/Keratin 20 positive intestinal type epithelium and the muscularis layer was shared by the cyst and adjacent jejunum, without a cleavage plane between the cyst wall and jejunal muscularis propria. In the deep muscularis propria, a Heinrich's type Ⅰ ectopic pancreas was also noted. In the pancreatic tail, a low grade intraepithelial lesion(panIN-1a) was diagnosed. This case highlights the necessity for a correct differential diagnosis of such rare lesions. Roughly 30 cases of jejunal duplication cysts have been reported to date in the PubM ed database.