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.

Duodenal carcinoid tumor: report of a case diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy with immunocytochemical correlation

Fine-needle aspiration biopsy is a reliable and accurate method for the endoscopic diagnosis of gastrointestinal malignancies and it is particularly well suited for evaluation of submucosal lesions. We report the cytopathologic findings of a case of malignant carcinoid tumor of a 44-year-old male who presented with melena and a nonhealing duodenal ulcer. Endoscopic ultrasound examination revealed a submucosal lesion in the pyloric region. Fine-needle aspiration revealed abundant cellularity with tumor cells arranged in sheets and loose groups and dispersed single cells in a clean background. Papillary fragments, capillaries cuffed by tumor cells, and rosette formation were also noted. The cells were moderate in size, round to oval, with a small subpopulation of spindle-shaped cells. The nuclei were uniform, round to oval, with smooth nuclear borders. The chromatin pattern was finely granular with a salt-and-pepper appearance. The cytoplasm of the cells was small to moderate in amount, pale, and showed fine granularity. The differential diagnosis included a neuroendocrine neoplasm vs. an epithelioid gastrointestinal stromal tumor. The tumor cells were focally positive for chromogranin and negative for CD34, supporting the diagnosis of a neuroendocrine neoplasm. The differential diagnosis of primary gastrointestinal carcinoid tumors from gastrointestinal stromal tumors can be very difficult in cytologic material. In cases when diagnostic material is scant, or only present on one smear, the use of smear division and cell transfer in order to perform immunocytochemical stains may be of considerable value to confirm the neuroendocrine nature of the neoplasms.

Foregut carcinoids: a clinical and biochemical analysis

BACKGROUND

Gastrointestinal foregut carcinoids make up a small percentage (3% to 6%) of all reported carcinoids. Because these tumors are so uncommon, comparisons between the subtypes have been difficult. The goal of this study was to compare the hormonal and clinical characteristics of gastric, duodenal, and pancreatic carcinoids.

METHODS

A prospective database of approximately 750 carcinoid patients seen by one author over 25 years was reviewed, and the 104 patients with gastric (33), duodenal (17), or pancreatic (54) carcinoids were selected as the subgroup for analysis. These patients were compared with regard to hormone levels, clinical course, treatment, and survival.

RESULTS

Duodenal carcinoids exhibited significantly lower serotoninergic hormone levels than did the gastric and pancreatic carcinoids (urine 5-hydroxyindoleacetic acid [mg/24 h], 5 +/- 1 vs 16 +/- 5 and 47 +/- 12, respectively, P = .03). Pancreatic carcinoids presented with more advanced stage (distant metastases 87% vs 42% and 20% for gastric and duodenal, respectively) and had worse outcomes than patients with gastric and duodenal tumors with 10-year survivals of 10%, 59%, and 58%, respectively (P = .003).

CONCLUSIONS

Pancreatic carcinoids produce higher levels of serotoninergic hormones and have a significantly higher stage and worse outcome than other foregut carcinoids. This study demonstrates that the organ of origin is an important determinant of hormonal activity and clinical course for patients with foregut carcinoids.

Primary anaplastic large cell lymphoma of the small intestine

We describe the clinicopathologic, immunophenotypic, and molecular findings in 4 cases of anaplastic large cell lymphoma (ALCL) arising in the small intestine. All patients were men with acute symptoms of gastrointestinal tract obstruction. The clinical preoperative diagnosis was gastrointestinal carcinoma in 3 cases, and pancreatic carcinoma in 1 case. Histologic examination revealed cohesive aggregates of neoplastic cells, with multiple vesicular nuclei, prominent nucleoli, and abundant amphophilic cytoplasm. There was no clinical or histopathologic evidence of enteropathy. All cases were CD30+, and all showed evidence of T-cell lineage with cytotoxic potential by expression of CD3, CD43, or CD45RO; T-cell intracellular antigen-1; or perforin. One tumor showed p80 and anaplastic lymphoma kinase (ALK) overexpression corroborated by the presence of the t(2:5). One tumor expressed Epstein-Barr virus latent membrane protein. In all cases, the tumor cells were negative for CD20, CD15, CD56, and cytokeratin. Polymerase chain reaction revealed clonal rearrangements of the T-cell receptor gamma-chain gene, without evidence of immunoglobulin heavy-chain gene rearrangement. The diagnosis of primary bowel ALCL is facilitated by immunophenotypic and molecular studies. With 24 months of clinical follow-up, only the patient with the t(2:5)-positive tumor is alive and free of disease, suggesting that p80/ALK overexpression may be a good prognostic indicator.

'Pyloric gland-type adenoma' arising in heterotopic gastric mucosa of the duodenum, with dysplastic progression of the gastric type

'Pyloric gland-type adenoma' is a recently described and very rare entity. We report a case of a pedunculated polyp of the duodenal bulb showing the features of pyloric gland-type adenoma. Heterotopic gastric mucosa was found adjacent to the tumour. Immunohistochemically, the tumour cells at the surface of the polyp showed foveolar-type mucin (M1) while most other tumour cells showed deep gastric mucin (M2), displaying a pattern of differentiation similar to the normal gastric mucosa. The polyp also showed villous or papillary structures with disorganization of gastric differentiation and marked increase of proliferating in foci cells. This is the first case of pyloric gland-type adenoma found to arise in heterotopic gastric mucosa of the duodenum, showing dysplastic progression of the gastric type.

Type VI collagen immunoreactivity in skeinoid fibers in small intestinal stromal tumors

By immunoperoxidase analysis for types I to VI collagen, elastin, cytoskeletal components and some glycoproteins, we found type VI collagen immunoreactivity in amorphous eosinophilic deposits (skeinoid fibers) in three small intestinal stromal tumors. Negative results were obtained for types I, II, III, IV and V collagen, elastin, laminin, ubiquitin, intracellular filaments such as actin, desmin, vimentin, calponin and caldesmon, and glycoprotein such as lysozyme, factor XIIIa, beta2-microglobulin, alpha1-antitrypsin and alpha1-antichymotrypsin. In two lesions, the periodic acid-Schiff-positive skeinoid fibers were also focally labeled for amyloid P component.

Carcinoid tumors of the ampulla of Vater: a comparison with duodenal carcinoid tumors

BACKGROUND

Although ampullary carcinoid tumors (ACs) are often categorized clinically as duodenal carcinoid tumors (DCs), there are distinct clinical and pathologic differences.

METHODS

Clinical, histopathologic, and immunohistochemical features of 12 ACs were compared with those of 53 DCs that did not involve the ampulla.

RESULTS

Patients with AC were ages 28-74 years (mean, 54.9 years); 8 were males and 4 were females. Five were white and three were black; the race of four patients was not known. The size of ACs ranged from 0.2 to 5.0 cm in greatest dimension. There were no significant differences between AC patients and DC patients with respect to male predominance, race, tumor size, and mitotic rate. The insular growth pattern was more common in AC; the cribriform type was more common in DC. Four of 12 ACs contained psammoma bodies, versus none of 53 DCs (P = 0.001). The rate of metastasis was similar in patients with AC (4 of 12, 33%) compared with DC patients (14 of 53, 26%). In DC patients, involvement of the muscularis propria, a size greater than 2 cm, and mitotic activity were significantly correlated with metastatic risk. In AC patients, tumor size and mitotic activity had no correlation with metastatic potential. One AC had features of an atypical carcinoid tumor; there were none in the duodenal group. One-half of patients with AC presented with jaundice versus 7% of patients with DC (P = 0.005). Three patients (25%) with AC had von Recklinghausen disease versus 0 of 53 patients with DC (P = 0.003). Immunohistochemically, tumor cells expressed somatostatin in 67%, serotonin and cholecystokinin in 17%, insulin in 25%, and glucagon and gastrin in 0% of ACs. In contrast, 56% of DCs expressed gastrin (P < 0.001).

CONCLUSIONS

Carcinoid tumors of the ampulla differ clinically, histologically, and immunohistochemically from carcinoid tumors elsewhere in the duodenum.

Antitumor effect of a neutralizing antibody to vascular endothelial growth factor on liver metastasis of endocrine neoplasm

Distant metastasis of gastrointestinal endocrine neoplasm is resistant to currently available treatments. Because hematogenic metastasis is dominant, anti-angiogenic drugs are expected to be a novel therapy for this neoplasm. In the present study, the therapeutic effect of vascular endothelial growth factor neutralizing antibody (VEGFAb) on liver metastasis of an endocrine neoplasm was investigated experimentally. Cecal transplantation into nude mice of small pieces of EN-1, a xenotransplanted human intestinal endocrine neoplasm, resulted in liver metastasis. A treated group (n = 19) received 100 micrograms/mouse of VEGFAb intraperitoneally on alternate days from day 10 after tumor transplantation, and the control group (n = 19) received saline. Five of the 19 control mice died of tumor progression, of which 2 could not be evaluated. The cecal tumor weighed 6316 +/- 2333 mg (n = 17) in the control group and 1209 +/- 837 mg (n = 19) in the treated group (P < 0.01) 6 weeks after transplantation. Liver metastasis developed in 16 of 17 control mice and in 2 of 19 treated mice (P < 0.01). The VEGF level of the whole cecal tumor in the control group was significantly higher than that in the treated group (305.1 +/- 174.1 vs. 54.7 +/- 41.2 mg; P < 0.001). VEGFAb did not cause any body weight loss (28.52 +/- 1.63 in the control vs. 28.44 +/- 1.71 g in the treated group). These results indicate that VEGFAb may be a novel therapeutic agent for endocrine neoplasm with distant metastasis.

Intestinal tumorigenesis in compound mutant mice of both Dpc4 (Smad4) and Apc genes

The DPC4 (SMAD4) gene plays a key role in the TGFbeta signaling pathway. We inactivated its mouse homolog Dpc4 (Smad4). The homozygous mutants were embryonic lethal, whereas the heterozygotes showed no abnormality. We then introduced the Dpc4 mutation into the Apc(delta716) knockout mice, a model for human familial adenomatous polyposis. Because both Apc and Dpc4 are located on chromosome 18, we constructed compound heterozygotes carrying both mutations on the same chromosome by meiotic recombination. In such mice, intestinal polyps developed into more malignant tumors than those in the simple Apc(delta716) heterozygotes, showing an extensive stromal cell proliferation, submucosal invasion, cell type heterogeneity, and in vivo transplantability. These results indicate that mutations in DPC4 (SMAD4) play a significant role in the malignant progression of colorectal tumors.

Small intestinal stromal tumors: a clinicopathologic study of 20 cases with immunohistochemical assessment of cell differentiation and the prognostic role of proliferation antigens

Small intestinal stromal tumors (SISTs), similar to their gastric counterpart, are complex because of their divergent cellular differentiation and because of the difficulty in accurately predicting their clinical outcome. We studied a series of 22 SISTs from 20 patients to characterize lineage and investigate prognostic morphologic parameters and possible histologic and immunohistochemical differences from gastric stromal tumors (GSTs) and to determine the potential prognostic value of proliferation markers. Cases were categorized into the three following groups based on mitotic count (MC) per 50 high-power fields and tumor size: (1) benign, n = 6 (< 5 MC, < 5 cm); (2) borderline, n = 6 (< 5 MC, > or = 5 cm); and (3) malignant, n = 10 (> or = 5 MC, any size). For the formalin-fixed, paraffin-embedded tissue sections, an immunohistochemical panel was used to characterize differentiation toward myogenic cells (pan-muscle specific actin [HHF-35], alpha-smooth muscle actin, and desmin), Schwann cells (S-100 protein), enteric glial (glial fibrillary acidic protein), and nerve cells (neurofilament). Cellular proliferative activity was assessed immunohistochemically using monoclonal antibodies to proliferating cell nuclear antigen (PCNA) and Ki-67 antigen (MIB-1) and a tumor proliferation index (TPI) was obtained as the percentage of positive-staining tumor nuclei. Clinical follow-up revealed that none of the benign tumors progressed (mean follow-up, 96 months). Half of the patients with borderline tumors were dead of disease (mean, 50.7 months), while 8 of 9 patients with a malignant tumor died of disease (mean, 24.6 months). By Cox Proportional Hazard Regression analysis, mitotic count, tumor size, and cellularity significantly predicted survival. PCNA, MIB-1, tumor necrosis, and atypia were not significant predictors of survival. All tumors stained with vimentin; 17 (77%) and 13 (59%) of the tumors showed immunoreactivity with muscle-specific actin markers (HHF-35) and alpha-smooth muscle actin, respectively. Only 1 tumor stained with desmin, and none stained with S-100 protein, neurofilament, or glial fibrillary acidic protein. Immunophenotypic characteristics did not differ among the 3 groups. The TPI for PCNA and MIB-1 significantly differed between benign and malignant tumors and between borderline and malignant tumors, but it failed to separate the benign and borderline groups. Compared with 52 cases of GST previously reported by us using the same criteria and antibody panel, these tumors were histologically and immunohistochemically indistinguishable. However, none of the 18 borderline GSTs progressed, while 3 of 6 patients with a borderline SIST died of the disease. Based on this series of 22 SISTs, we conclude the following: (1) MC, size, and cellularity are the best predictors of clinical outcome in SIST. (2) The majority of SISTs show smooth muscle differentiation based on their immunoreactivity with HHF-35 and alpha-smooth muscle actin). (3) The TPI for PCNA and MIB-1 correlated with MC but failed to predict survival for individual cases. (4) SISTs and GSTs are morphologically and immunohistochemically similar; however, SISTs seem to have greater malignant potential than GSTs of similar size.

Numerous eosinophilic globules (skeinoid fibers) in a duodenal stromal tumor: an exceptional case showing smooth muscle differentiation

A unique case of duodenal stromal tumor in a 51-year-old man is reported. The tumor histologically showed spindle cell proliferation and numerous eosinophilic globules. Most globules were composed of tangled 45 nm thick fibrils, which were ultrastructurally identical to 'skeinoid fibers'. The presence of glycogen granules in the tumor cells and the immunoreactivity for alpha-smooth muscle actin suggested smooth muscle differentiation. Focal ultrastructural findings also supported the smooth muscle nature of this tumor. There were no immunohistochemical and ultrastructural features indicating neural differentiation. In previous studies, the presence of such 'skeinoid fibers' was suggested to be a histological marker for neural differentiation in gastrointestinal stromal tumor. However, the findings in the present case suggest that numerous 'skeinoid fibers' can be identified in duodenal stromal tumor with smooth muscle differentiation, although this condition may be rare.

Gangliocytic paraganglioma of the duodenum: report of a case with immunocytochemical and ultrastructural investigation

A case of gangliocytic paraganglioma is reported in a 70-year-old female presenting as a polypoid tumor of the second portion of the duodenum. Immunohistochemical and ultrastructural features of the tumor indicate that gangliocytic paraganglioma of the duodenum (GPD) represents an unique tumor originating from the neuroectodermal derivative exhibiting dual phenotypic expression toward paraganglionic and epithelial (neuroendocrine) cells. These findings correlate well with the literature and it is further suggested that GPD belongs to the histopathologic spectrum of tumors derived from the neural crest. The findings offer a plausible explanation for histogenetic possibilities of the occurrence of pure epithelial tumors (i.e., carcinoid-like tumors) in the paraganglionic systems. The patient remains with no evidence of disease 4 years following a simple polypectomy.

Proliferative characteristics of differentiated cells in familial adenomatous polyposis-associated duodenal adenomas

The authors have previously shown that duodenal adenomas in familial adenomatous polyposis (FAP) patients typically reveal abundant cells with endocrine differentiation (ED), Paneth differentiation (PD), and goblet cell differentiation (GD). However, the biological significance and proliferative potential of these cells is unknown. To study the proliferative properties of cells with ED, PD, or GD in FAP-associated duodenal adenomas, the authors used a double-labeling immunohistochemical technique to detect simultaneously the presence of proliferating cell nuclear antigen (PCNA), and either chromogranin or lysozyme in individual neoplastic cells. Adenomatous cells with GD were identified morphologically and also evaluated for the degree of PCNA expression by immunohistochemistry. Duodenal adenomas and the adjacent nonadenomatous epithelium from 10 FAP patients were studied. Cells with ED, PD, and GD were present in all adenomas, and constituted 14.1%, 11.6%, and 17.7% of adenomatous cells, respectively. The overall proliferative index of nondifferentiated adenomatous cells was 33.3%, which was similar to the proliferative index obtained for adenomatous cells with GD (31.2%) and nonadenomatous crypt goblet cells (34.9%). In contrast, adenomatous cells with ED and PD showed a significant decrease in their proliferative potential (P < .001). Only 6.0% and 7.3% of cells with ED and PD, respectively, were proliferative. Nonadenomatous crypt endocrine and Paneth cells showed no proliferative potential (proliferative index 0%). These results suggest that, in the process of proliferation and differentiation, specific subpopulations of adenomatous cells attempt to recapitulate the biological characteristics of their normal counterparts in the small intestinal crypts. Adenomatous cells with ED and PD are hypoproliferative, a finding that is consistent with their differentiated phenotype and suggests that these cells may not participate as actively in the growth of these lesions.

Two cases of duodenal gangliocytic paraganglioma: immunocytochemical characteristics

Two cases of duodenal gangliocytic paraganglioma were studied by means of immunocytochemical methods using 41 kinds of antibodies. The tumors consisted of three histological types; carcinoid, ganglioneuroma and paraganglioma. Tumors of both cases exhibited immunoreactivity to at least one or as many as three of the following: calcitonin, calcitonin-gene related peptide, endocrine granule constituent, Leu7, neuropeptide Y and basic fibroblast growth factor. In addition, these tumors were also immunopositive for neuron specific enolase, S-100 protein, neurofilament protein, pancreatic polypeptide, chromogranin A, somatostatin, leuenkephalin, substance P and vasoactive intestinal peptide, as has been described in previous reports. In one case, tumor cells were immunopositive for adrenocorticotropin, bombesin, gastrin releasing peptide, myelin basic protein, neuroendocrine marker and tyrosine hydroxylase. Moreover, paraganglioma cells of tumors showed both argyrophilia and argentaffinity. These results suggest that duodenal gangliocytic paraganglioma may originate from embryonic neuroinsular complex.

Aberrant insulinoma of the duodenal bulb

A rare insulin-immunoreactive neuroendocrine tumor of the duodenum in a 54 year old male is reported. The incidentally identified tumor was located on the anterior free wall of the duodenal bulb and measured approximately 6 mm in diameter. Uncomplicated endoscopic resection of the tumor was carried out. The lesion exhibited classic histologic features of insulinoma of the beta-islet cell type with stromal amyloid deposition. In addition to positive reactivities of chromogranin A, neuron-specific enolase, synaptophysin, Leu 7 (CD57), cystatin C, CA15-3 and cytokeratin, the non-argyrophilic tumor cells were strongly immunoreactive for insulin and C-peptide. The stromal amyloid was clearly labeled for amylin. A few cells were stained for somatostatin, whereas other hormones were negative. Interestingly, a few isolated insulin-positive cells were identified in the non-neoplastic duodenal mucosa in the proximity of the tumor. Immunoelectron microscopy using paraffin sections disclosed insulin-immunoreactive secretory granules in the cytoplasm. The patient exhibited no signs or symptoms of hypoglycemia. Serum insulin levels were not measured prior to resection. No tumors were demonstrated in the pancreas. Magnetic resonance imaging revealed a 1 cm asymptomatic pituitary mass, in association with moderately elevated serum prolactin levels. The patient is currently being followed up in the outpatient clinic.

Use of an isotopic somatostatin receptor probe to image gut endocrine tumors

OBJECTIVES

To evaluate the effectiveness of indium In 111 pentetate (diethylenetriaminepentaacetic acid [DTPA]-D-Phe-labeled octreotide scintigraphy in the localization of gastroenteropancreatic neuroendocrine lesions, and to identify covert lesions, determine multicentricity, define the distribution of metastases, confirm complete removal of tumor postoperatively, and evaluate the efficacy of therapeutic embolization.

DESIGN

Unmasked comparison.

SETTING

Tertiary care referral center.

PATIENTS

We studied 28 patients over a 12-month period. Biochemical evidence of a gastroenteropancreatic tumor was present in 13 patients. Octreoscan 111 was employed in four patients with an ambiguous biochemical diagnosis of gastroenteropancreatic tumor. Postoperative examination to document complete tumor removal was undertaken in seven patients. In one patient, Octreoscan 111 was used to evaluate the efficacy of therapeutic embolization.

INTERVENTION

[111In]DTPA-D-Phe-octreotide scintigraphy.

MAIN OUTCOME MEASURE

Identification of somatostatin receptor-bearing neuroendocrine tumors.

RESULTS

Intravenous administration of [111In]DTPA-D-Phe-octreotide followed by whole-body gamma camera scintigraphy resulted in the localization of gastroenteropancreatic neuroendocrine tumors with 75% sensitivity, 100% specificity, 100% positive predictive value, 63% negative predictive value, and 82% overall accuracy.

CONCLUSIONS

While Octreoscan 111 has been shown to localize the majority of amine precursor uptake and decarboxylation system (APUD) cell tumors as well as various other somatostatin-positive tumors, this technique may also be useful in a number of other circumstances. These include prediction of tumors that will respond to octreotide therapy, identification of covert metastases, intraoperative identification of tumors, and postoperative surveillance. Use of an alternative isotope may provide a vehicle for the administration of local therapeutic radiation to tumor cells. The precise efficacy of Octreoscan 111 in the identification of lesions smaller than 3 cm with low-density somatostatin-2 receptor expression remains to be determined.

Epithelioid angiosarcoma of the intestinal tract with endothelin-1-like immunoreactivity

Two rare cases of intestinal epithelioid angiosarcoma arising in the sigmoid colon and small intestine are reported. The small intestinal tumours were located in the duodenum and upper jejunum. All tumours showed reddish-black protuberant masses with comparatively clear margins. Histology reveals solid and epithelioid growth of large polygonal cells, mimicking undifferentiated carcinoma. Vascular differentiation such as lamina containing red cells and intracytoplasmic vacuolization is noticed. Intense immunoreactivity to Ulex europaeus agglutinin I and JC70 (CD31), and sporadic positive reaction to factor VIII related antigen were detected in one case but not in the other. However, both tumours have cells which show intense endothelin-1 immunoreactivity. Positive immunostaining occurred with low molecular weight keratins suggesting epithelial differentiation and suggested epithelioid angiosarcoma as a diagnosis, a specific entity within angiosarcoma. Because of their histological features, epithelioid angiosarcomas may be confused with undifferentiated carcinomas. Endothelin-1-like immunoreactivity seems to be a good marker for this type of angiosarcoma, even when the tumour cells lack usual marker substances for endothelial cells.

Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts) in the duodenum: the first visceral case

An ulcerated tumour was removed by a Whipple's operation from the descending part of the duodenum of a 38-year-old male. The tumour cells were mainly spindle-shaped, arranged in nests and had very prominent nucleoli. A few cells contained melanin and melanosomes. Immunoreactivity for S-100 protein and focally for HMB-45 was observed. These features are diagnostic for clear cell sarcoma of tendons and aponeuroses. Because no other primary tumour could be found and the search for similar cases from the literature was unsuccessful, we believe that this tumour is the first reported clear cell sarcoma in a visceral location.

Establishment of a CD4-positive plasmacytoma cell line (AMO1)

A human plasmacytoma cell line (AMO1) was established. The AMO1 cells had the light and electron microscopic characteristics typical of plasmacytoma cells and did not harbor Epstein-Barr virus. These cells expressed cytoplasmic immunoglobulin A kappa and the immunoglobulin heavy-chain gene (JH) and kappa light-chain gene (C kappa) were rearranged. Coexpression of a CD4 antigen and plasma cell antigens (CD38 and PCA-1) was an unusual and sustained feature. Neither the T-cell receptor beta nor the gamma chain gene displayed the rearranged form. Other lineage-specific surface antigens, namely T, B, monocytoid, and myeloid antigens, were all negative in AMO1. In accordance with the surface CD4 expression, polymerase chain reaction analysis indicated constitutive expression of CD4 mRNA, and the cytogenetic findings revealed that AMO1 cells had a derivative chromosome 12, which had a structural abnormality of the short arm carrying the CD4 gene locus. These findings provide strong evidence for the presence of CD4-positive malignant plasma cells and raise the possibility that the CD4 expression in the AMO1 cell line is closely associated with the derivative chromosome.

Argyrophil-negative G-cell duodenal carcinoid

A case of mono-hormonal-producing and functionally active G-cell carcinoid tumor of the duodenum is described. The tumor, found to be argyrophil negative, was investigated immunohistochemically and ultrastructurally. We report our results, then discuss the possible histochemical causes that can lead to the failure of argyrophilia, and direct attention to the possible misdiagnosis that can result from that failure.

Small Intestinal Stromal Tumors With Skeinoid Fibers

Microscopic appearances of spindle cell tumors of the gastrointestinal tract are suggestive of smooth muscle origin; however, they usually lack specific muscle cell features by electron microscopy and immunohistochemistry, thus justifying their designation as stromal tumors. The present report describes nine cases of small intestinal stromal tumors with eosinophilic stromal globules composed of tangles of curved fibers with crossbands simulating an appearance of skeins, designated as skeinoid fibers. Patients' ages ranged from 28 to 87 years; and four were male. The tumors presented as well-delineated mural nodules ranging from 1.8 to 13 cm in size, causing intestinal obstruction or hemorrhage. Four were in the duodenum, three in the jejunum, and two unspecified. Microscopically, seven were benign; one, to the largest, was definitely malignant and metastasized to the liver. Another, the second largest (7.5 cm), showed moderate atypia with two mitoses per 10 high-power fields. The light microscopic appearance, including immunohistochemistry, were typical for small intestinal stromal tumors. Skeinoid fibers were strongly periodate-Schiff's procedure-positive and stained blue with the trichrome stain. They appeared as a few micra-sized specks to large globules reaching a few millimeters. Skeinoid fibers were also found in three neurogenic spindle cell tumors (an acoustic neuroma, a neurofibroma, and a plexosarcoma of the mesentery), suggesting that such fibers are possible ultrastructural markers for neurogenic tumors and thus small intestinal stromal tumors with skeinoid fibers are neurogenic in origin.

Exocrine pancreatic insufficiency and pancreatic fibrosis due to duodenal somatostatinoma in a patient with neurofibromatosis

A case of duodenal somatostatinoma is described in a patient with Von Recklinghausen neurofibromatosis. The patient presented with exocrine pancreatic insufficiency, probably due to distal obstruction of the pancreatic duct by the tumor. Preoperative evaluation with calcium-pentagastrin and tolbutamide stimulation tests were nondiagnostic. At laparotomy, local excision of the tumor was performed. Pathological findings were compatible with duodenal somatostatinoma, causing pancreatic fibrosis. Somatostatin extracted from the tumor coeluted with the somatostatin-14 standard on high performance liquid chromatography (HPLC).

von Recklinghausen's disease associated with somatostatin-rich duodenal carcinoid (somatostatinoma), medullary thyroid carcinoma and diffuse adrenal medullary hyperplasia

This report describes the concomitant occurrence of a somatostatin-rich duodenal carcinoid, a medullary thyroid carcinoma and a diffuse adrenal medullary hyperplasia in a patient with von Recklinghausen's disease. A 50-year-old Japanese man died from lung metastasis of a malignant schwannoma. In addition to extensive viscero-cutaneous neurofibromatosis, two different types of neuroendocrine tumors were found in the duodenum and thyroid gland at autopsy. The duodenal tumor, which was located in the second portion, showed the histologic appearance of a carcinoid tumor with glandular differentiation and psammoma-bodies. Immunohistochemically the tumor cells were intensely positive for somatostatin. The thyroid tumor was composed of nests of tumor cells arranged in an endocrine pattern, and showed immunoreactivity for calcitonin. A review of the literature revealed no previously reported case of concomitant occurrence of duodenal somatostatinoma and medullary thyroid carcinoma in a single patient with von Recklinghausen's disease. Morphometric analysis of adrenal glands disclosed the presence of diffuse medullary hyperplasia. Thus, the present case exhibited a similarity in some respects with multiple endocrine neoplasia (MEN) syndrome, Type IIa or IIb.