Metastatic Patterns of Duodenopancreatic Neuroendocrine Tumors in Patients With Multiple Endocrine Neoplasia Type 1

Patients with multiple endocrine neoplasia 1 syndrome (MEN1) often develop multifocal duodenopancreatic neuroendocrine tumors (dpNETs). Nonfunctional pancreatic neuroendocrine tumors (PanNETs) and duodenal gastrinomas are the most frequent origins of metastasis. Current guidelines recommend surgery based on tumor functionality, size ≥2 cm, grade or presence of lymph node metastases. However, in case of multiple primary tumors it is often unknown which specific tumor metastasized. This study aims to unravel the relationship between primary dpNETs and metastases in patients with MEN1 by studying endocrine differentiation. First, it was shown that expression of the endocrine differentiation markers ARX and PDX1 was concordant in 18 unifocal sporadic neuroendocrine tumors (NETs) and matched metastases. Thereafter, ARX, PDX1, Ki67 and gastrin expression, and the presence of alternative lengthening of telomeres were determined in 137 microscopic and macroscopic dpNETs and 36 matched metastases in 10 patients with MEN1. ARX and PDX1 H-score clustering was performed to infer relatedness. For patients with multiple metastases, similar intrametastases transcription factor expression suggests that most metastases (29/32) originated from a single NET of origin, while few patients may have multiple metastatic primary NETs. In 6 patients with MEN1 and hypergastrinemia, periduodenopancreatic lymph node metastases expressed gastrin, and clustered with minute duodenal gastrinomas, not with larger PanNETs. PanNET metastases often clustered with high grade or alternative lengthening of telomeres-positive primary tumors. In conclusion, for patients with MEN1-related hypergastrinemia and PanNETs, a duodenal origin of periduodenopancreatic lymph node metastases should be considered, even when current conventional and functional imaging studies do not reveal duodenal tumors preoperatively.

Neuroendocrine Tumors (NETs) of the Minor Papilla/Ampulla: Analysis of 16 Cases Underlines Homology With Major Ampulla NETs and Differences From Extra-Ampullary Duodenal NETs

Neuroendocrine tumors (NETs) of the minor papilla/ampulla (MIPA) are rare and poorly studied. Only individual case reports and no comprehensive analysis are available from the literature. We collected 16 MIPA NETs and investigated their clinicopathologic and immunohistochemical features, including markers such as somatostatin, pancreatic polypeptide, gastrin, serotonin, MUC1, cytokeratin 7, and somatostatin receptors type 2A and 5. The median age at diagnosis was 57.5 years, and the female-to-male ratio was 2.2:1. The median NET size was 1.45 cm, and most (94%) were low-grade (G1) tumors. Similarly to what was observed in the major ampulla, 3 histotypes were found: (i) ampullary-type somatostatin-producing tumors (ASTs, 10 cases), characterized by somatostatin expression in most tumor cells, focal-to-extensive tubulo-acinar structures, often with psammoma bodies, MUC1 reactivity, and no or rare membranous reactivity for somatostatin receptor type 2A; (ii) gangliocytic paragangliomas (3 cases), characterized by the coexistence of 3 tumor cell types: epithelioid, often reactive for pancreatic polypeptide, ganglion-like cells, and S100 reactive sustentacular/stromal cells; and (iii) ordinary nonfunctioning NETs (3 cases), resembling those more commonly observed in the extra-ampullary duodenum. Comparable histotypes could also be recognized among the 30 MIPA NETs from the literature. No NET-related patient death among MIPA cases was observed during a median follow-up of 38 months; however, MIPA ASTs showed lymph node metastases and invasion of the duodenal muscularis propria or beyond in 44% and 40% of cases, respectively. In conclusion, MIPA NETs closely resemble tumors arising in the major ampulla, with predominance of ASTs.

Metastasis of extra-ampullary duodenal adenocarcinoma to the uterine cervix

Secondary metastatic tumours of the uterine cervix are rare. There have been no reports of duodenal cancer metastasizing to the uterine cervix. Here we present a rare case of an extra-ampullary duodenal adenocarcinoma that has metastasized to the uterine cervix. The patient was a 71-year-old woman who had surgery for an extra-ampullary duodenal adenocarcinoma five years previously. Follow-up examination revealed a suspicious right ovarian mass and nodules in the cervix and posterior fornix of the vagina. Biopsies suggested squamous cell carcinoma in the cervix and adenocarcinoma in the fornix. Intraoperatively, the right ovary was enlarged and peritoneal disseminations were found in the pouch of Douglas and the sigmoid colon mesentery. Histopathology of the subsequent hysterectomy and bilateral salpingo-oophorectomy specimen revealed a cervical squamous cell carcinoma categorized as pT1b1. Adenocarcinoma infiltration into the ovaries, uterine cervix and vagina, with vascular involvement was detected. Immunohistochemistry revealed the tumour in the cervix and ovaries to be positive for CK7, MUC5AC and MUC6, and immunonegative for CK20, CDX2, Pax8, ER, MUC2 and CD10, similar to the original duodenal adenocarcinoma. This case illustrates the difficulty in making a preoperative diagnosis of metastatic adenocarcinoma in the uterine cervix with a coexisting primary cervical squamous cell carcinoma. The absence of atypia in cervical glandular cells and immunohistochemical profiling of the adenocarcinoma clusters helped to reach a final diagnosis. This is the first report of an extra-ampullary duodenal adenocarcinoma metastasis to the uterine cervix.

Epithelial turnover in duodenal familial adenomatous polyposis: A possible role for estrogen receptors?

AIM: To investigate estrogen receptors expression in duodenal familial adenomatous polyposis (FAP) and any relationship with epithelial proliferation/apoptosis markers.

METHODS: Twenty-two patients affected by FAP undergoing duodenal resection for malignancies were recruited. Controls were 15 healthy subjects undergoing endoscopy for dyspeptic symptoms. ER-α, ER-α, Ki-67, TUNEL and caspase 3 expression (labeling index: percentage of positive cells) were evaluated by immunohistochemistry or immunofluorescence and examined by light or confocal microscopy. Samples were assigned to four groups: normal tissue, low (LGD) and high-grade dysplasia (HGD), adenocarcinoma (AC). One-way analysis of variance, corrected by Bonferroni’s test, and Pearson’s correlation test were applied for statistical analysis.

RESULTS: ER-beta showed a progressive decline: normal tissue (23.5 ± 4.9), LGD (21.1 ± 4.8), HGD (9.3 ± 3.5), AC (7.1 ± 3.1). The normal tissue of FAP subjects expressed ER-beta like the controls (23.9 ± 6.2). Conversely, ER-α showed a progressive increase from normal tissue (24.8 ± 5.6) to AC (52.0 ± 8.2); the expression in normal tissue was similar to controls (22.5 ± 5.3). Ki67 demonstrated a statistically significant progressive increase at each disease stage up to AC. TUNEL did not reveal differences between controls and normal tissue of FAP subjects, but progressive decreases were observed in LGD, through HGD to AC. Pearson’s correlation test showed a direct relationship between ER-β and TUNEL LI (r = 0.8088, P < 0.0001). Conversely, ER-α was inversely correlated with TUNEL LI (r = - 0.7257, P < 0.0001). The co-expression of ER-β and caspase 3 declined progressively from normal to neoplastic tissue.

CONCLUSION: This study confirmed that ER-β is strongly decreased in duodenal FAP carcinomas, declining in a multiple step fashion, thereby suggesting a putative anti-carcinogenic effect. ER-α showed the opposite trend. ER-β/caspase 3 co-expression suggests this hormone’s possible involvement in apoptosis. Hormonal influences in FAP duodenal tumorigenesis, and modulation of these as a possible chemoprevention strategy, may be a promising approach.

Traditional serrated adenomas of the upper digestive tract

For many years, it was generally accepted that the vast majority of the colorectal carcinomas (CRCs) evolved from conventional adenomas, via the adenoma–carcinoma sequence. More recently, serrated colorectal polyps (hyperplastic polyps, sessile serrated polyps and traditional serrated adenomas (TSAs)) have emerged as an alternative pathway of colorectal carcinogenesis. It has been estimated that about 30% of the CRC progress via the serrated pathway. Recently, TSAs were also detected in the upper digestive tract. In this work, we review the literature on TSA in the oesophagus, the stomach, the duodenum, the pancreatic main duct and the gallbladder. The review indicated that 53.4% (n=39) out of the 73 TSA of the upper digestive tract now in record showed a simultaneously growing invasive carcinoma. As a corollary, TSAs of the upper digestive tract are aggressive adenomas that should be radically excised, either endoscopically or surgically, to rule out the possibility of a synchronously growing invasive adenocarcinoma or to prevent cancer progression. The present findings substantiate a TSA pathway of carcinogenesis in the upper digestive tract.

Perivascular epithelioid cell tumor in the duodenum: challenge in differential diagnosis

Defined as a family of scarce mesenchymal neoplasm which distinctively co-express melanocytic markers and muscle markers, perivascular epithelioid cell tumors (PEComas) have been reported almost everybody site. Perivascular epithelioid cell tumors-not otherwise specified (PEComas-NOS) arising in the gastrointestinal (GI) tract are still restricted into sporadic case reports. Herein we present a case of GI PEComas-NOS which occurs in the duodenum of a 27-year-old male. Our initial diagnosis tended to gastrointestinal stromal tumor or smooth muscle tumor till the correct diagnosis of perivascular epithelioid cell tumor (PEComa) was established by postoperative pathological examination. We also make a literature review of GI PEComas-NOS and highlight the challenge it brings to the differential diagnosis.

Endoscopic mucosal resection of duodenal bulb adenocarcinoma with neuroendocrine features: An extremely rare case report

Duodenal adenocarcinoma, especially duodenal bulb with neuroendocrine features (NEF), is extremely rare. Here, we report one such case of duodenal bulb adenocarcinoma with neuroendocrine features. A 63-year-old Han Chinese woman was admitted to our department with the diagnosis of a duodenal bulb polyp and underwent an endoscopic mucosal resection. The pathological findings confirmed it as duodenal bulb adenocarcinoma with NEF. The patient remains curative after one and half a years of follow-up. Duodenal adenocarcinoma with NEF might be a low malignant neuroendocrine tumor rather than a conventional adenocarcinoma. Endoscopic treatment, including endoscopic mucosal resection, might be an ideal option for the adenocarcinomas with NEF.

Adenocarcinoma arising from heterotopic pancreas at the third portion of the duodenum

A 62-year-old Japanese man presented to our hospital with a history of weight loss of 6 kg in 4 mo. Imaging examinations revealed a tumor located on the third portion of the duodenum with stenosis. We suspected duodenal carcinoma and performed pancreas-preserving segmental duodenectomy. Adenocarcinoma arising from a heterotopic pancreas at the third portion of the duodenum was finally diagnosed by immunohistochemical staining. Malignant transformation in the duodenum arising from a heterotopic pancreas is extremely rare; to our knowledge, only 13 cases have been reported worldwide, including the present case. The most common location of malignancy is the proximal duodenum at the first and descending portion. Herein, we describe the first case of adenocarcinoma arising from a heterotopic pancreas, which was located in the third portion of the duodenum, with a review of the literature.

β-catenin Helices in the cytoplasm of sporadic and FAP duodenal adenomas

BACKGROUND

Initiation and progression in conventional adenomas is triggered by deregulation of Wnt/β-catenin signaling. In the absence of Wnt signal (off-state), β-catenin prevents phosphorylation of glycogen synthase kinase (GSK)-3β leading to aberrant nuclear accumulation in human tumors. While investigating the nuclear expression of β-catenin in biopsies from duodenal adenomas, we observed a non-previously reported phenomenon, namely the presence of β-catenin cytoplasmic helices (coils).

MATERIALS AND METHODS

Sections from 39 biopsies were immunostained with β-catenin: 25 from duodenal adenomas and the remaining 14 had normal duodenal mucosa (n=11) or polypoid gastric duodenal metaplasia (n=3).

RESULTS

Eighteen out of the 25 duodenal adenomas (72%) showed β-catenin helices; in contrast, none of the 33 control biopsies (including those with normal duodenal mucosa, gastric duodenal metaplasia and normal mucosa adjacent to 19 adenomas) showed β-catenin helices (p<0.05). The review of diagnostic H&E-stained sections and of β-catenin-stained nuclei revealed that the dysplastic nuclei were arranged in a picket fence-like fashion along the basement membrane of the glands and not as loops within the dysplastic glands; the nuclei of the dysplastic glands were not forming part of the β-catenin helices.

DISCUSSION

If these β-catenin coils are unrelated to an abnormal nuclear distribution at the base of the dysplastic glands, the rational explanation might be that the helices highlight changes taking place in the cytoplasm of affected glandular cells.

CONCLUSION

According to some authors, mutations in the β-catenin genes are always associated with a morphologically neoplastic course. It is herein proposed that β-catenin helices in duodenal adenomas might uncover a novel cytoplasmic phenomenon ensuing during the adenoma-carcinoma pathway.

Malignant gangliocytic paraganglioma of the duodenum with distant metastases and a lethal course

Gangliocytic paraganglioma (GP) is rare and has been regarded as benign in general with a good prognosis. We present a patient with duodenal GP showing a malignant and lethal clinical course. A 47-year-old male patient was found to have a duodenal tumor and enlarged regional lymph nodes. The patient initially underwent a pancreaticoduodenectomy to resect the tumor and involved lymph nodes completely. Histological and immunohistochemical analyses showed findings typical of GP. However, the distant metastatic lesions in the liver and pelvic cavity were rapidly observed after surgery. The patient underwent chemotherapy and radiotherapy, as well as a second surgery to partly remove the metastatic mass in the pelvic cavity. The histological examination revealed no significant difference in histological features between the primary duodenal tumor and the metastatic pelvic mass. However, the patient finally died of the tumor due to the recurrence of the residual pelvic lesion and increased liver mass. To our knowledge, this is the first report of lethal GP with multifocal metastases. Our case confirms that GP should be regarded as a malignant potential tumor with behavior code of “1”, rather than a benign tumor of “0”.

A case of ampullary gangliocytic paraganglioma

Gangliocytic paragangliomas (GPs) are rare tumors of the duodenum, presenting as single sessile or pedunculated polypoid masses. Clinical manifestations of duodenal GPs can vary from an incidental finding at endoscopy to frequent upper gastrointestinal bleeding caused by mucosal ulceration and abdominal pain. GPs are considered benign, but the disease can recur and spread to regional lymph nodes. A 41-year-old female presented with abdominal pain. Upper gastrointestinal endoscopy revealed a subepithelial tumor of the ampulla of Vater in the second portion of the duodenum. The tumor was resected using the endoscopic mucosal resection technique. The tumor was diagnosed as benign GP of the duodenum using histological and immunohistochemical staining procedures.

Gastrointestinal stromal tumors of the duodenum: Surgical management and survival results

AIM: To provide long-term survival results of operable duodenal gastrointestinal stromal tumors (DGISTs) in a tertiary center in China.

METHODS: In this retrospective study, the pathological data of 28 patients with DGISTs who had been treated surgically at the Second Department of General Surgery, Sir Run Run Shaw Hospital (SRRSH) from June 1998 to December 2006 were reviewed. All pathological slides were examined by a single pathologist to confirm the diagnosis. In patients whose diagnosis was not confirmed by immunohistochemistry at the time of resection, representative paraffin blocks were reassembled, and sections were studied using antibodies against CD117 (c-kit), CD34, smooth muscle actin (SMA), vimentin, S-100, actin (HHF35), and desmin. Operative procedures were classified as wedge resection (WR, local resection with pure closure, without duodenal transection or anastomosis), segmental resection [SR, duodenal transection with Roux-Y or Billroth II gastrojejunostomy (G-J), end-to-end duodenoduodenostomy (D-D), end-to-end or end-to-side duodenojejunostomy (D-J)], and pancreaticoduodenectomy (PD, Whipple operation with pancreatojejunostomy). R0 resection was pursued in all cases, and at least R1 resection was achieved. Regional lymphadenectomy was not performed. Clinical manifestations, surgery, medical treatment and follow-up data were retrospectively analyzed. Related studies in the literature were reviewed.

RESULTS: There were 12 males and 16 females patients, with a median age of 53 years (20-76 years). Their major complaints were “gastrointestinal bleeding” (57.2%) and “nonspecific discomfort” (32.1%). About 14.3%, 60.7%, 17.9%, and 7.1% of the tumors originated in the first to fourth portion, respectively, with a median size of 5.8 cm (1.6-20 cm). Treatment was by WR in 5 cases (17.9%), SR in 13 cases (46.4%), and by PD in 10 cases (35.7%). The morbidity and mortality rates were 35.7% and 3.6%, respectively. The median post-operative stay was 14.5 d (5-47 d). During a follow-up of 61 (23-164) mo, the 2-year and 5-year relapse-free survival was 83.3% and 50%, respectively. Eighty-four related articles were reviewed.

CONCLUSION: Surgeons can choose to perform limited resection or PD for operable DGISTs if clear surgical margins are achieved. Comprehensive treatment is necessary.

Multivisceral resection for advanced duodenal adenocarcinoma: a case report and review of literature

The aim of this paper is to address adenocarcinoma of the duodenum by reporting a case, reviewing the literature and discussing current knowledge, diagnostic modalities and treatment options. We present a case of a 42-year-old patient with duodenal adenocarcinoma at the second portion invading surrounding organs. The patient had a previous history of colon malignancy and was diagnosed with a new tumour formation on regular CT (computed tomography) follow-up. Pylorus-preserving pancreaticoduodenectomy (PPPD) was preformed for this T4 N2 M1 tumor. Duodenal adenocarcinoma is a rare tumor, most frequently involving the second duodenal portion. It has no specific symptoms and it is difficult to diagnose it due to its rarity and clinical presentation. Diagnosis, exact localization, and involvement of lymph nodes and surrounding organs have an impact on surgical strategy and prognosis.

Duodenal carcinoma from a duodenal diverticulum mimicking pancreatic carcinoma

An 81-year-old man was found to have a pancreatic head tumor on abdominal computed tomography (CT) performed during a follow-up visit for sigmoid colon cancer. The tumor had a diameter of 35mm on the CT scan and was diagnosed as pancreatic head carcinoma T3N0M0. The patient was treated with pylorus-preserving pancreaticoduodenectomy. Histopathological examination showed that the tumor had grown within a hollow structure, was contiguous with a duodenal diverticulum, and had partially invaded the pancreas. Immunohistochemistry results were as follows:CK7 negative, CK20 positive, CD10 negative, CDX2 positive, MUC1 negative, MUC2 positive, MUC5AC negative, and MUC6 negative. The tumor was diagnosed as duodenal carcinoma from the duodenal diverticulum. Preoperative imaging showed that the tumor was located in the head of the pancreas and was compressing the common bile duct, thus making it appear like pancreatic cancer. To the best of our knowledge, this is the second report of a case of duodenal carcinoma from a duodenal diverticulum mimicking pancreatic carcinoma.

Clear cell myomelanocytic tumor (PEComa) of the duodenum in a child with a history of neuroblastoma

We report herein a case of digestive clear cell myomelanocytic tumor (PEComa) that is unique in its location and presentation. The lesion, located in the duodenal wall, was diagnosed in a child with a history of cervical neuroblastoma that was in remission after surgical resection and chemotherapy. The diagnosis was obtained by examination of a biopsy specimen taken during laparoscopy. The decision was made to perform surgical resection. Examination of the surgical specimen confirmed the diagnosis of PEComa. No metastasis was found. After 2 years of follow-up, the patient is alive, without evidence of metastasis or recurrence. This case highlights the distinctive characteristics of the cells in PEComa, recognizable even on limited biopsy material. It also suggests a possible association between PEComa and neuroblastoma, 2 unusual tumors that belong to the spectrum of lesions known to occur in patients with tuberous sclerosis and that may share a possible common pathogenetic mechanism.

Glomus tumor of the duodenum: a case report

We describe a rare case of glomus tumor of the duodenum. The tumor was detected in a 46-year-old man being investigated for episodes of gastrointestinal bleeding. The excised specimen showed a 2.3 x 1.5 x 1.5 cm gray-tan tumor involving the mucosa and the submucosa. The overlying mucosa was focally ulcerated. Histologically, the tumor had a solid pattern of sharply demarcated, round glomus cells with prominent pericytoma-like vessels of varying sizes. The neoplastic cells stained for vimentin, smooth muscle actin, and focally for synaptophysin. These histologic and immunohistochemical features are consistent with a diagnosis of glomus tumor of the duodenum.

Extensive cutaneous metastases in a dog with duodenal adenocarcinoma

A 6-year-old Rottweiler was presented to the North Carolina State University College of Veterinary Medicine for evaluation of multiple cutaneous nodules. The dog had a history of anorexia, vomiting, and hind-limb paraplegia. Results of cytologic examination of the cutaneous nodules were consistent with a round cell tumor. At necropsy, primary tumors were found coalescing in the duodenum and the pancreas and extending into the associated mesentery. Numerous masses also were found throughout the skin, abdominal and thoracic viscera, and lumbar spinal cord. Histologically, the duodenal tumor had variable morphology, with some areas resembling adenocarcinoma and others resembling anaplastic round cell neoplasia; the skin and other metastatic lesions resembled round cell neoplasia. Immunohistochemistry of the cutaneous, duodenal, and pancreatic masses showed the neoplastic cells were positive for pancytokeratin, supporting an epithelial origin. In addition, low numbers of neoplastic cells were positive for periodic acid-Schiff and Alcian blue, consistent with acid mucin production by duodenal epithelium. These findings confirmed that the cutaneous nodules were metastatic lesions originating from the duodenal adenocarcinoma. Cutaneous metastasis of intestinal carcinoma is rare in domestic animals. This case demonstrates the potential difficulty in diagnosing metastatic lesions based on cytologic and histologic morphology alone, because the cutaneous metastases may not resemble the primary neoplasm morphologically.

Gastrointestinal stromal tumors, intramural leiomyomas, and leiomyosarcomas in the duodenum: a clinicopathologic, immunohistochemical, and molecular genetic study of 167 cases

In this study we analyzed the clinicopathologic features of duodenal smooth muscle or stromal tumors, including 156 GISTs, 6 leiomyomas (LMs), and 5 leiomyosarcomas (LMSs) from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki. GISTs were documented as KIT positive (n = 109); 47 tumors were also included because of their histologic identity to KIT-positive cases. GIST-specific c-kit gene mutations were documented in exon 11 in 9 of 30 cases (30%) and exon 9 in 4 of 30 cases (13%). The GISTs occurred in patients with an age range of 10-88 years (median 56 years); 54% were male. Ten patients had neurofibromatosis type I; six of them had multiple GISTs. The GISTs ranged from small asymptomatic intramural or external nodules to large masses that extended into the retroperitoneum (median size 4.5 cm). They were mostly spindle cell tumors; three malignant GISTs had an epithelioid morphology, and 81 cases had skeinoid fibers. The tumors often coexpressed CD34 and KIT (54%) and were variably positive for smooth muscle actin (39%) and S-100 protein (20%) but never for desmin. A total of 86% of patients with tumors >5 cm with >5 mitoses/50 high power fields (HPF) (n = 21) died of disease, whereas no tumor <2 cm with <5 mitoses/50 HPF (n = 12) recurred or caused death. Long latency was common between primary operation and recurrences or metastases; either one occurred in 49 of 140 patients with follow-up (35%). No formula could accurately predict metastases, which occasionally developed even if mitotic activity was <5/50 HPF and size <5 cm. Metastases were in the abdominal cavity, liver, and rarely in bones and lungs but never in lymph nodes. Four actin- and desmin-positive and KIT-negative benign intramural LMs were similar to those more often seen in the esophagus. There were five LMSs, one of which formed a polypoid intraluminal mass; all were actin positive and KIT negative. The great majority of duodenal mesenchymal tumors are GISTs, which have a spectrum from small indolent tumors to overt sarcomas. LMs and LMSs are rare.

[Prognostic significance of Ki67 and p53 protein in small bowel stromal tumor immunopositive for CD117]

OBJECTIVE

To investigate the correlative factors of the prognosis by observing the immunohistochemical features of small bowel stromal tumors(SBST).

METHODS

Thirty-three cases of stromal tumors with expressed CD117 were examined by the light microscope. The expressions of Ki67 and p53 protein with EnVision + staining were detected in the tumors and compared with the morphology.

RESULTS

The group included 20 males and 13 females whose ages ranged from 21 to 71 years (median: 46 years); the tumors were situated in duodenum (5 cases), jejunum (22 cases) and ileum (6 cases). Grossly, tumors size was from 1.5 to 20 cm. In eleven cases tumors showed foci of tumor cell necroses. In all these cases, mitotic counts ranged from 0 to 62 mitotic figures per 50 HPF (high-power fields), six of 33 tumors had no mitotic figures per 50 HPF, 5 cases had 1-2 mitotic figures and 22 cases had > or = 3 mitotic figures. Histologically, 4 cases classified as benign, 4 cases as borderline and 25 cases as malignant. Follow-up of 7 cases with benign and borderline tumors were alive without tumor. In the malignant group of 23 cases, 6 patients died of disease, 10 patients were alive with evidence of metastatic disease, and 7 patients were alive without tumor. Immunohistochemically, 31 of 33 stromal tumors were positive for Ki67, 16 cases of malignant tumors showed significant staining (> 5% cells). 31 of 33 tumors were positive for p53 protein, and all the 25 (100%) malignant tumors showed staining. In 12 of the 25 cases, the staining was strong and diffuse(> 50% cells). When the Ki67 and p53 proteins were negative or showed focal expressions (Ki67 < 1% and p53 < 10%), the patients presented a good prognosis. And when there were strong expressions (Ki67 > 5% and p53 > 50%), the patients portended a poor prognosis.

CONCLUSION

Immunohistochemical analysis of Ki67 and p53 protein was a better method in the prognosis. When Ki67 showed strong position, it was a bad sign. When p53 protein showed strong position, it might be the potential malignant parameter. When Ki67 and p53 proteins were all strong expressions, these patients portended a poor prognosis. In addition to the invasion and metastasis, tumor size, mitotic counts and tumor cell necrosis were also helpful parameters for diagnosis of malignancy.

Colorectal cancer in mice genetically deficient in the mucin Muc2

The gastrointestinal tract is lined by a layer of mucus comprised of highly glycosylated proteins called mucins. To evaluate the importance of mucin in intestinal carcinogenesis, we constructed mice genetically deficient in Muc2, the most abundant secreted gastrointestinal mucin. Muc2-/- mice displayed aberrant intestinal crypt morphology and altered cell maturation and migration. Most notably, the mice frequently developed adenomas in the small intestine that progressed to invasive adenocarcinoma, as well as rectal tumors. Thus, Muc2 is involved in the suppression of colorectal cancer.

Duodenal somatostatinoma of the ampulla of vater diagnosed by endoscopic fine needle aspiration biopsy: a case report

BACKGROUND

Duodenal somatostatinoma is a rare neuroendocrine neoplasm. A better prognosis can be obtained if these tumors are resected at an early clinical stage. Endoscopic punch biopsy has been the method most commonly used for the preoperative diagnosis of neuroendocrine duodenal tumors. To the best of our knowledge, endoscopic fine needle aspiration biopsy (FNAB) of duodenal somatostatinoma has not been reported before.

CASE

A 41-year-old, black female presented with upper gastrointestinal bleeding as well as elevated bilirubin, liver enzymes and glucose. Computed tomography, esophagogastroduodenoscopy and endoscopic retrograde cholangiopancreatography (ERCP) detected a mass at the region of the ampulla of Vater partially obstructing the pancreatic duct. The initial punch biopsy yielded only intestinal mucosa. Subsequent endoscopic FNAB suggested the diagnosis of a neuroendocrine neoplasm, as confirmed by additional punch biopsies. Immunohistochemical and electron microscopic studies disclosed somatostatin production by the tumor, which was resected through a modified Whipple procedure. The patient recovered fully.

CONCLUSION

This case demonstrates the usefulness of endoscopic FNAB in diagnosing submucosal gastrointestinal neuroendocrine tumors.

Mutations in c-kit gene exons 9 and 13 in gastrointestinal stromal tumors among Japanese

Gain-of-function mutation in c-kit proto-oncogene exon 11 has been described in about 20 -- 50% of gastrointestinal stroma tumor (GIST). Recently, additional mutational hot-spots in exon 9 and exon 13 of the c-kit gene have been reported in GISTs without mutations of exon 11, but a subsequent report in a Western population indicated that only a small portion of GISTs (eight of 200 GISTs, 4%) showed mutations in these regions. In this study, we evaluated mutations in exon 9 and exon 13 of the c-kit gene by both polymerase chain reaction-single strand conformation polymorphism analysis and direct sequencing in 48 GISTs in a Japanese population, for which the clinicopathological and immunohistochemical features and mutations in exon 11 had previously been reported. C-kit gene mutation in exon 9, representing insertion of GCC TAT, was identified in only 4 of 48 GISTs (8%), and none of the GISTs had mutations in exon 13. All four GISTs with mutation in exon 9 were high-risk, and the patients died of multiple tumor metastasis. Mutations in exon 9 and exon 13 of the c-kit gene were also rare events in Japanese GISTs and were related to a poor prognosis. These results in Japanese are consistent with those in Western populations, although a preferential occurrence of GISTs with exon 9 mutation in the small intestine, which was suggested in a previous report, was not observed.

Immunocytochemical localization of prohormone convertase 1/3 and 2 in gastrointestinal carcinoids

Gastrointestinal carcinoids are derived from the diffuse intestinal endocrine system and may produce amines and many peptides, including serotonin, chromogranin A (CGA), and tachykinins. Most peptide hormones are synthesized as bigger prohormones, which are processed to smaller active hormones by prohormone convertases (PCs). A total of 35 cases of gastrointestinal carcinoids, including gastric, duodenal, small intestinal, appendiceal, and large intestinal carcinoids, were immunocytochemically stained for serotonin, CGA, and PC 1/3 and 2, in order to colocalize CGA and PCs in the carcinoids. All carcinoids were positive for CGA and PCs. Carcinoids that stained strongly for CGA were generally weakly stained for PCs and those weakly staining for CGA were more strongly stained for PCs in the majority of the small and large intestinal tumors. Gastrointestinal carcinoids were positive for CGA and PCs, and the presence of PCs may suggest that the conversion of peptide prohormones to smaller peptide hormones occurs in gastrointestinal carcinoids. PCs immunocytochemistry may be added as a new phenotypic characterization for gastrointestinal carcinoids.