LARGE HYPERPLASTIC POLYP DEVELOPING AFTER ENDOSCOPIC MUCOSAL RESECTION OF GASTRIC ADENOMA IN A PATIENT RECEIVING IMMUNOSUPPRESSIVE THERAPY

A 59‐year‐old man underwent endoscopic mucosal resection (EMR) for gastric adenoma. He had suffered from end‐stage renal disease for several years and had received renal transplantation some 5 months before EMR. Subsequently, he took immunosuppressive agents. Follow‐up gastrofiberscopy 6 months after EMR showed a sessile polyp at the resection site twice as large as the original adenoma; biopsy specimens revealed a hyperplastic nature. At the time of writing, this hyperplastic polyp has neither increased in size nor developed adenomatous or carcinomatous changes by histological examinations over the past 5 years. Therefore, this is a case of hyperplastic polyp occurring at the gastric adenoma resection site, and suggests the possible effect of immunosuppressive therapy on the post‐EMR healing process and hyperplastic polyp development.     

A rare case of a signet ring cell carcinoma of the colon mimicking a juvenile polyp

Primary signet ring cell carcinoma (SRC) of colon at early stage is quite rare. Only 26 cases were reported until now. We report an early stage of primary SRC which was misdiagnosed as a juvenile polyp and treated with polypectomy followed by surgical resection. A 21-year-old male was administered for hematochezia. Abdominopelvic enhanced computed tomography revealed a polyp with active bleeding at the proximal rectum just below the rectosigmoid junction. Colonoscopy examination revealed a colon polyp with 0.5 cm sized head. Polypectomy was performed with snare and the polyp was completely removed. Biopsy revealed SRC. Surgical resection was also performed and there were no residual tumor or lymph node metastasis in the surgical specimen.     

Papillary adenocarcinoma occurring in a gastric hyperplastic polyp observed by magnifying endoscopy and treated with endoscopic mucosal resection

The patient was a 75-year-old man. He had been diagnosed with gastric hyperplastic polyp 4 years previously. The color of the apex of this polyp was whitish. Magnifying endoscopy findings revealed disappearance of the mucosal microstructure with irregular branched capillaries at the top of the polyp. Endoscopic mucosal resection (EMR) was performed. Histological examination revealed that a part of the polyp surface was replaced with papillary adenocarcinoma. Diagnosis of papillary adenocarcinoma in a hyperplastic polyp with mucosal invasion was made. Magnifying endoscopy was useful for the detection of gastric cancer occurring in the hyperplastic polyp in the present case.     

Pedunculated gastric carcinoma demonstrating a gastric foveolar phenotype

We report a case of gastric cancer complicated with very well differentiated adenocarcinoma containing signet ring cells. An endoscopic examination revealed a pedunculated polyp in the fornix of the stomach. A surgical operation was performed and the pathological findings showed very well differentiated adenocarcinoma mimicking gastric foveolae with a poorly differentiated component containing signet ring cells. This is the first case of pedunculated gastric cancer complicated with very well differentiated adenocarcinoma containing signet ring cells and also demonstrating a gastric foveolar phenotype.     

A case of gastric hamartomatous inverted polyp (submucosal tumor type) accompanied by gastric cancer]

Endoscopic examination of a 39-year-old woman revealed a flat-elevated submucosal tumor (SMT) in the upper third area of the stomach and a IIc lesion in the anterior wall of the lower third of the stomach. Endoscopic ultrasonography findings suggested an aberrant pancreas. Both lesions were resected by distal gastrectomy. Histological examination of the SMT revealed the dilated glands with cyst formation and proliferation of smooth muscle bundles in the submucosal layer, and it was diagnosed as a gastric hamartomatous inverted polyp. The IIc lesion was a signet ring cell carcinoma. Cases of gastric hamartomatous inverted polyps coexistent with gastric cancer have been rarely reported in Japan.     

A Small Gastric Cancer in Association with Menetrier Disease

Abstract: We studied a 57-year-old man who was diagnosed as having giant rugae at a mass-screening for gastric cancer. He was examined endoscopically for check-up purposes. In addition to giant rugal folds which occurred throughout the entire fundus and body of the stomach, a type IIc lesion was noted in the posterior lower wall of the gastric body. A biopsy revealed signet ring cell carcinoma. A total gastrectomy was performed. A resected specimen was serially sectioned and underwent histopathological examination; hypertrophy and cystic elongation of the gastric glands indicative of so-called giant hypertrophic gastritis was seen. The histological type of the type IIc lesion was undifferentiated adenocarcinoma with the signet ring cells being confined to the mucosal layer. This patient had a rare case of Menetrier's disease complicated by intramucosal carcinoma.     

Endoscopic features of early-stage signet-ring-cell carcinoma of the stomach

AIM: To identify the features of early signet ring cell gastric carcinoma using magnification endoscopy with narrow band imaging (NBI).METHODS: A retrospective review was conducted of 12 cases of early signet ring cell gastric carcinoma who underwent treatment in a single institution between January 2009 and April 2013. All patients had magnification endoscopy with NBI and indigo carmine contrast to closely examine the mucosal architecture, including the microvasculature and arrangement of gastric pits. Histologic examination of the final endoscopic submucosal dissection or gastrectomy specimen was performed and compared with the endoscopic findings to identify patterns specific to signet ring cell carcinoma.RESULTS: Twelve patients with early signet ring cell gastric carcinoma were identified; 75% were male, and average age was 61 years. Most of the lesions were stage T1a (83%), while the remainder were T1b (17%). The mean lesion size was 1.4 cm². On standard endoscopy, all 12 patients had a pale, flat lesion without any evidence of mucosal abnormality such as ulceration, elevation, or depression. On magnification endoscopy with NBI, all of the patients had irregularities in the glands and microvasculature consistent with early gastric cancer. In addition, all 12 patients exhibited the “stretch sign”, an elongation or expansion of the architectural structure. Histologic examination of the resected specimens demonstrated an expanded and edematous mucosal layer infiltrated with tumor cells.CONCLUSION: The “stretch sign” appears to be specific for signet ring cell carcinoma and may aid in the early diagnosis and treatment of this aggressive pathology.     

Vimentin-positive gastric adenocarcinoma arising in a hyperplastic polyp

We report a case of vimentin-positive early gastric adenocarcinoma arising in a hyperplastic polyp (HP). A 72-year-old Japanese man was admitted for the detailed examination of a gastric polyp. He had a subtotal gastrectomy due to acute abdomen 12 years ago. Upper endoscopy revealed a pedunculated polyp measuring approximately 2 cm on the greater curvature of upper body of the remnant stomach. Magnifying endoscopy revealed that the microsurface pattern was irregular and partially absent accompanied with irregular microvessels at the upper end of the polyp. We speculated that the lesion was an adenocarcinoma arising in the HP. Endoscopic submucosal dissection (ESD) was performed. Histological examination of the ESD specimen revealed that the lesion consisted of well- to poorly differentiated adenocarcinoma at the protruding lesion and foveolar hyperplastic epithelia at the base of the polyp. Immunohistochemically, most of tumor cells that comprised poorly-differentiated adenocarcinoma were positive for both cytokeratin and vimentin. Although carcinomas have occasionally been found in HPs, the histological features of the present case are considered extremely unusual. To the best of our knowledge, this is the first case of vimentin-positive early gastric carcinoma arising in a HP.     

Early-stage primary signet ring cell carcinoma of the colon

Primary signet ring cell carcinoma of the colorectum detected at an early stage is very rare; most cases are detected at an advanced stage. Therefore, its progno-sis is poorer than that of ordinary colorectal cancer. A 56-year-old Korean man was seen at this hospital for management of signet ring cell carcinoma of the co-lon. Colonoscopic examination revealed a Ⅱa-like, ill-defined and flatly elevated 9-mm residual tumor in the cecum. Endoscopic mucosal resection was preformed. Pathological examination of the resected specimen re-vealed signet ring cell carcinoma that had invaded the lamina propria without venous or perineural invasion. Abdominal computed tomography (CT) and positron CT showed no evidence of primary lesions or distant me-tastasis. An additional laparoscopic right-hemicolectomy was performed; no residual tumor or lymph node me-tastasis was found. We report a case of primary signet ring cell carcinoma of the colon detected at an early stage and provide a review of the literature.     

Coexistence of multifocal gastric adenocarcinoma with signet-ring cell morphology and a gastrointestinal stromal tumour in a stomach with hp-associated gastritis

A 79-year-old man was admitted because of anemia during marcumar therapy with suspected bleeding in the gastrointestinal tract. Endoscopy revealed a large mutifocal poorly differentiated gastric signet ring cell adenocarcinoma. After staging by the usual oesophagogastroduodenoscopic method, a total D 2 gastrectomy was performed. In the pathological resection specimen of the stomach, a multifocal poorly differentiated signet ring cell adenocarcinoma, infiltrating the submucosa (so called early cancer of sm-type) and an incidental gastroinstinal stromal tumour, 0.8 cm in diameter, was diagnosed. This is the first case report of the synchronous occurrence of a multifocal poorly differentiated gastric adenocarcinoma with signet-ring cell morphology (diffuse type according to the Lauren classification) and a GIST incidentally within a stomach with Hp-associated gastritis.     

A case of gastric hyperplastic polyp with malignant transformation

In this paper we report a case of hyperplastic polyp with malignant transformation. The patient was followed up by annual radiographic and endoscopic examination during 9 years. The first gastroscopy revealed a semi-pedunculated polyp beneath the esophageal-cardiac junction, 1.5cm in diameter and slightly reddish with smooth surface. Histological findings showed a hyperplastic polyp. There was slight change in size, but no change in histological examination of the lesion during the follow-up. In 1996, the biopsy specimen showed an atypical epithelium and the polyp was removed by snear polypectomy. A microscopic examination revealed a well-differentiated adenocarcinoma. Immunohistochemically, p53 and Ki-67 immunostaining showed positive in the carcinoma portion of the adenocarcinoma bearing a hyperplastic polyp in the stomach.     

Multiple depressed‐type colonic cancer (IIC)‐like configurations: metastases from gastric cancer

We present a rare case of multiple colonic metastases from advanced gastric cancer presenting colon depressed‐type multiple early cancer (IIc)‐like configuration. The case was a 74‐year‐old man who presented with a symptom of abdominal fullness. Colonoscopy and barium enema study revealed multiple IIc‐like lesions, which were shown histologically to be metastatic deposits of signet ring cell carcinoma. He had synchronous gastric cancer, which histologically demonstrated moderate to poorly differentiated adenocarcinoma with signet ring cell differentiation. In addition, he had concomitant multiple small bowel metastatic lesions. This appears to be the first published report of multiple IIc‐like colonic metastatic lesions from a gastric cancer.     

SYNCHRONOUS MULTICENTRIC SIGNET‐RING CELL CARCINOMA OF THE STOMACH

A case of simultaneous multicentric signet‐ring cell carcinoma (SRC) of stomach is presented. Initially, an early gastric cancer (IIc) was diagnosed and this was cured with distal gastrectomy. Thirty‐eight months after the operation, follow‐up endoscopy revealed a tiny mucosal discoloration lesion, which was diagnosed as a minute SRC focus with biopsy. This was successfully treated with endoscopic mucosal resection (EMR). Nine months later, gastroscopy discovered another small mucosal lesion and it was again diagnosed as a tiny SRC lesion, which was also successfully treated with EMR. After a further 2 months, endoscopy showed three small mucosal lesions (discoloration) similar to previous lesions, two of which proved to be SRC with biopsy. As these lesions distributed widely over the remnant stomach, total gastrectomy of the residual stomach was performed. Pathological examination demonstrated a total of 22 simultaneous multifocal SRC lesions, which were all very small mucosal cancer. These cancers, including previously EMR‐treated ones, seemed to develop in a multicentric manner, as they were diagnosed within 11 months. This case also indicated that even subtle endoscopic findings should vigorously be sought and, if in doubt, be biopsied in order to locate gastric cancer early enough for minimal invasive curative treatment to be feasible.     

Dynamic enhanced computed tomography imaging findings of an inflammatory fibroid polyp with massive fibrosis in the stomach

Inflammatory fibroid polyp(IFP) is a rare benign lesion of the gastrointestinal tract. We report a case of computed tomography(CT) imaging finding of a gastric IFP with massive fibrosis. CT scans showed thickening of submucosal layer with overlying mucosal hyperenhancement in the gastric antrum. The submucosal layer showed increased enhancement on delayed phase imaging. An antrectomy with gastroduodenostomy was performed because gastric cancer was suspected, particularly signet ring cell carcinoma. The histopathological diagnosis was an IFP with massive fibrosis. The authors suggest that when the submucosal layer of the gastric wall is markedly thickened with delayed enhancement and preservation of the mucosal layer, an IFP with massive fibrosis should be considered in the differential diagnosis.     

Signet Ring Cell Carcinoma in Hyperplastic Polyp

Background: A polypectomy was performed on a 68-year-old woman who had three gastric hyperplastic polyps. A focal signet ring cell carcinoma was discovered in one of the polyps, which was 2.2 cm in diameter and was located in the antrum. Methods: To study the carcinoma's phenotypic expression, special mucin histochemical stainings were performed. Results: The carcinoma infiltrated only into the mucosa. Intestinal metaplasia was scant. In the neoplasm neutral and foveolar mucin was predominant over acid mucin. The surrounding hyperplastic foveolar epithelium showed positivity for neutral mucin, and the intestinal metaplasia foci for acid mucin. Conclusions: This neoplasm has a mixed composition of mucins and shares histochemical characteristics with the surrounding hyperplastic foveolar epithelium.     

Flat gastric polyps: results of forceps biopsy, endoscopic mucosal resection, and long-term follow-up

OBJECTIVE: Histological examination of specimens obtained by forceps biopsy sampling of gastric polyps is of limited accuracy, and their management on this basis is therefore controversial. The aim of this prospective study was to assess the value of forceps biopsy sampling in establishing the correct diagnosis revealed by endoscopic mucosal resection (EMR). The complication rate of EMR was also determined. MATERIAL AND METHODS: Subjects with gastric polyps of epithelial origin, of at least 0.5 cm in diameter, and not associated with polyposis syndromes, were included in the study. Between 1994 and 2004, 56 gastric polyps in 44 patients (30 F, 14 M, mean age 67 years) met the inclusion criteria. Indigo carmine dye staining and electronic magnification were used in all cases. Following forceps biopsy sampling, 56 EMRs were performed. The histological results of the forceps biopsy and the resected specimens were analyzed. RESULTS: The initial forceps biopsies identified in situ carcinoma in 3 cases, adenoma with no dysplasia in 19, adenoma with low-grade dysplasia in 2, adenoma with moderate-grade dysplasia in 6, adenoma with high-grade dysplasia in 7, and hyperplastic lesions in 19 cases. The histological examination of the resected polyps revealed in situ carcinoma in 5 cases, carcinoid in 1, gastrointestinal stromal tumor in 1, adenoma with no dysplasia in 14, adenoma with low-grade dysplasia in 3, adenoma with moderate-grade dysplasia in 9, adenoma with high-grade dysplasia in 1, hyperplastic lesions in 21, and no diagnosis in 1 case. Complete agreement between the histological results on the forceps biopsy sample and on the ectomized polyp was seen in only 31 (55.3%) polyps. There were important disagreements in 12 cases. In 14 neoplastic and 1 hyperplastic polyps, the degree of dysplasia seen on histological examination of the forceps biopsy specimens differed from that observed for the resected specimens. Post-mucosectomy bleeding was observed in 3 patients, all of whom were successfully treated endoscopically. CONCLUSIONS: Forceps biopsy is not sufficiently reliable for the identification of gastric polyps. These lesions should be fully resected by EMR for a final diagnosis and (depending on the lesion size and type) possibly definitive treatment.     

Primary rectal signet ring cell carcinoma with peritoneal dissemination and gastric secondaries

Disseminated signet ring cell carcinomas frequently arise from the stomach. However, primaries in the colon and rectum have also been reported. We present a 68 year old lady who presented with a change in her bowel habit. Colonoscopy showed a stenosing rectal tumour at 7 cm to 8 cm from the anal verge. Multiple scattered ulcers were also noted along the entire length of the colon. Biopsy of the lesions revealed signet ring cell adenocarcinoma. Gastroscopy showed multiple nodules with ulceration over several areas of the stomach which were similar in appearance to the colonic lesions. However, no primary tumour of the stomach was seen. Biopsy of the gastric lesions also showed signet ring cell adenocarcinoma. Computed tomography scan of the abdomen and pelvis revealed circumferential tumour at the rectosigmoid junction with possible invasion into the left ischiorectal fossa. The overall picture was that of a primary rectal signet ring cell carcinoma with peritoneal dissemination. The patient was referred for palliative chemotherapy in view of the disseminated disease. In the present report, we discuss this interesting pathological entity and review the role of various histolological techniques in helping to identify the primary tumor.     

Signet ring cell carcinoma of the lower bile duct with rapid growth: report of a case

Signet ring cell carcinoma occurring in the biliary tract is extremely rare. We herein report the case of a 78-year-old Japanese woman demonstrating signet ring cell carcinoma of the lower bile duct with a rapid growth. Computed tomography of the pancreas head pointed out a circular thickness in the lower bile ductal wall and stenosis of the common bile duct. Cholangiography revealed tapering stenosis at the lower bile duct. Biopsy specimens taken from these lesions and scratched specimens taken from stenotic portion of the lower bile duct were analyzed and demonstrated signet ring cell carcinoma. To the best of our knowledge, this is the first reported case of primary signet ring cell carcinoma of the lower bile duct reported in the English literature. Based on our experience, signet ring cell carcinoma of the lower bile duct is considered to demonstrate both transmural dispersion and an aggressive nature.     

A Huge Polypoid Type Early Gastric Neuroendocrine Cell Carcinoma

Abstract: We report a case of a huge polypoid-type early gastric neuroendocrine cell carcinoma. Upper gastrointestinal endoscopy in a 77-year-old man revealed a gastric polyp on the anterior wall of the corpus. Endoscopically biopsied material from the polyp suggested that the lesion was malignant; specifically a poorly and moderately differentiated tubular adenocarcinoma or adenocarcinoma with neuroendocrine differentiation. Endoscopically the lesion was a huge polypoid type with a broad stalk approximately 40 mm in diameter, and its surface was tabulated with a white coat and erosion. The patient underwent total gastrectomy. The resected specimen histopathologically showed a polypoid mass with medullary carcinoma and indicated endocrine cell differentiation. Immunohis-tochemical findings supported the diagnosis of endocrine cell carcinoma. This case was an early and polypoid-type gastric endocrine cell carcinoma. Since examples of such cases are rare in the literature, we report this case in brief.     

Ultrastructural cytochemical study of enzymes expressed by signet ring cells in gastric cancer

AIM: To study the ultrastructural localization of five marker enzymes (ALPase, ACPase, G6Pase, TPPase and CCOase) in gastric cancer signet ring cells to demonstrate their biologic behaviors.METHODS: Five marker enzymes were examined in signet ring cells of seven gastric cancer patients by ultrastructural enzyme cytochemical techniques.RESULTS: The number of corresponding organelles and the activities of marker enzymes, especially ACPase and TPPase, increased, leading to stronger mucus synthesis, secretion and digestion in gastric cancer signet ring cells. There was a lack of collagenous fibers in the stroma around the cancer nests.CONCLUSION: Signet ring cell carcinoma is very invasive with metastasis rates due to the secretion of proteolytic enzymes.