Gastrointestinal neuroendocrine cell proliferations

Injury patterns and potential diagnostic pitfalls associated with radiation and radio-chemotherapy in the stomach and gastroesophageal junction

Chemoradiation-associated injury may cause marked epithelial and stromal changes in gastric specimens. We characterized these histologic features in a retrospective series of cases. Nineteen cases of radiochemotherapy-associated gastropathy were identified, including 16 from our institution and 3 from consultation material. Patient charts and hematoxylin and eosin-stained slides were reviewed. Most patients were men (79%) with a median age of 66 years. All patients had a documented history of radiation and 15 patients also received chemotherapy. The median time from treatment to biopsy or resection was 2.3 months. Gross and endoscopic findings included erythematous, hemorrhagic, or ulcerated mucosa. Mucosal eosinophilia was seen in 16 cases (84%) while 10 cases (53%) featured acute inflammation including neutrophilic microabscesses. Epithelial changes included increased apoptosis (6 cases, 32%) and marked epithelial atypia (10 cases, 53%), potentially mimicking malignancy in some cases. However, the atypical cells featured voluminous eosinophilic cytoplasm with low nuclear-to-cytoplasmic ratio, a clue to their benign nature. Neuroendocrine cell nests were seen in 4 cases (21%) and loosely aggregated in 1 case, potentially mimicking a well-differentiated neuroendocrine tumor or enterochromaffin-like (ECL) cell hyperplasia in autoimmune gastritis. Eleven cases (58%) featured vascular changes that included vessel dilation, hobnailed endothelial cells, and fibrin thrombi. Stromal changes were seen in 11 cases (58%) and included lamina propria hyalinization, submucosal fibrosis, and myofibroblast atypia. Injury associated with radiochemotherapy is histologically varied and may affect epithelial, stromal, and vascular compartments. Familiarity with these features is important as a subset of these findings may provoke concern for neoplasia.

Amphicrine Carcinoma of the Ampullary Region

Amphicrine carcinoma is a peculiar tumor in which the cells have both exocrine and neuroendocrine differentiation, with mucus and neuroendocrine granules within the cytoplasm. In the 2010 WHO classification of tumors of the digestive tract, they have been included in the intermediate-grade malignant category of mixed adenoneuroendocrine carcinomas (MANECs). These tumors are extremely rare in the gastrointestinal tract. Four cases have been reported in the stomach, three in the pancreas, and one in the liver. To the best of our knowledge, this report describes the first case of amphicrine carcinoma in the ampullary region.

Relation of neuroendocrine cells to transforming growth factor-alpha and epidermal growth factor receptor expression in gastric adenocarcinomas: prognostic implications

The presence of neuroendocrine (NE) cells in gastric adenocarcinoma (GCa) is well documented, however, their significance is controversial. There is no evidence in the literature concerning the possible effect of these cells on the expression of TGF-alpha and EGFR, which are believed to confer growth advantage to tumor cells. 101 partial or total gastrectomy specimens from patients operated for conventional gastric adenocarcinoma were included in the study. In each case immunohistochemistry was performed on sequential tissue sections for chromogranin A (ChrA), TGF-alpha and EGFR. Samples were graded based on the number of ChrA-positive cells (0-3). TGF-alpha and EGFR expressions were evaluated according to both the intensity (0-2) and quantification of the positively stained areas (0-3). Follow-up data was available in 54 patients. Twenty-seven patients died of disease, while 27 patients were alive with a follow-up of at least 15 months. ChrA expression was detected in 54.4% of the tumor specimens. TGF-alpha was stained positively in 42.6% and EGFR in 49.5% of the cases. NE cells in GCa was related to TGF-alpha (p<0.0001) and EGFR expression (p<0.05), and TGF-alpha/EGFR coexpression (p<0.001). Among histopathologic variables, the presence of NE cells was significantly related to grade, stage and lymph node status. Although the presence of NE cells had no effect on survival, the expression of EGFR (p<0.0001) and TGF-alpha (p=0.002) were related to survival. The results of our study suggest that the presence of NE cells may have an effect on the expression of TGF-alpha and EGFR in GCa, and the autocrine mechanism between TGF-alpha and EGFR plays an important role in the prognosis of gastric carcinoma.

Gastric mucosal atrophy: interobserver consistency using new criteria for classification and grading

BACKGROUND AND AIMS

Considerable difficulties persist amongst pathologists in agreeing on the presence and severity of gastric atrophy. An international group of pathologists pursued the following aims: (i) to generate an acceptable definition and a simple reproducible classification of gastric atrophy; and (ii) to develop guidelines for the recognition of atrophy useful for increasing agreement among observers.

METHODS

After redefining atrophy as the 'loss of appropriate glands' and examining histological samples from different gastric compartments, three categories were identified: (i) negative; (ii) indefinite; (iii) atrophy, with and without intestinalization. Atrophy was graded on a three-level scale. Interobserver reproducibility of the classification was tested by kappa statistics (general and weighted) in a series of 48 cases.

RESULTS

The medians of the general agreement and weighted kappa values were 0.78 and 0.73, respectively. The weighted kappa coefficients, obtained by cross-tabulating the evaluation of each pathologist against all others, were, with only one exception, > 0.4 (moderate to excellent agreement).

CONCLUSIONS

By using the definition of atrophy as the loss of appropriate glands and distinguishing the two main morphological entities of metaplastic and non-metaplastic types, a high level of agreement was achieved by a group of gastrointestinal pathologists trained in different cultural contexts.

Site-specific epithelial-mesenchymal interactions in digestive neuroendocrine tumors. An experimental in vivo and in vitro study

Little is known about the functional interactions between digestive neuroendocrine tumor cells and their stromal microenvironment. The focus of our study is whether mesenchymal cells modulate peptide expression, cell proliferation, and invasiveness in digestive neuroendocrine tumor cells. We designed an experimental in vivo and in vitro study using the mouse enteroendocrine cell line STC-1. In vivo, STC-1 cells were injected subcutaneously in 18 immunosuppressed newborn rats. At day 21, all animals presented poorly differentiated neuroendocrine tumors with lung metastases. Subcutaneous tumors were usually limited by a capsule containing basement membrane components and myofibroblasts that presented a low mitotic index. Lung tumors were devoid of capsule and poor in myofibroblasts, and their mitotic index was high. The profile of peptide expression in STC-1 tumors was different from that of cultured STC-1 cells. In vitro, STC-1 cells were cultured with fibroblasts of different origins, including dermis, lung, digestive tract, and liver. Based on their origin, myofibroblasts differentially modulated hormone synthesis, proliferation, spreading, and adhesion of STC-1 cells. In conclusion, our results show that site-specific functional interactions between mesenchymal and neuroendocrine cells may contribute to modulating the behavior of digestive neuroendocrine tumors, depending on their growth site.

Brain metastases from adenoendocrine carcinoma of the common bile duct: a case report

A 68-year-old man with metastatic brain tumors from adenoendocrine carcinoma of the common bile duct is reported. A common bile duct tumor and a metastatic liver tumor had been resected 6 years and 3 years prior to admission, respectively. Microscopically they showed two components; moderately differentiated tubular adenocarcinoma and neuroendocrine carcinoma. He presented with headache and vomiting and MRI revealed two metastatic brain tumors. They were successfully resected and radiotherapy was carried out. Histological diagnosis of the metastatic brain tumors was neuroendocrine carcinoma, but carbohydrate antigen (CA)-19-9 and carcinoembryonic antigen (CEA)-immunoreactive cells were observed without glandular pattern. Immunohistochemically serotonin and pancreatic polypeptide were detected, but somatostatin was not. As the endocrine cells demonstrated in the normal extrahepatic bile ducts are only somatostatin-containing D cells, these cells are considered to originate as part of a metaplastic process. To our knowledge, this represents the second case of adenoendocrine carcinoma of the common bile duct.

Metastasis from small cell carcinoma of the lung producing acute appendicitis

A case of acute gangrenous appendicitis with perforation caused by metastatic small cell carcinoma of the lung in a 65 year old man is reported. The manifestation of appendicitis occurred more than 4 years after the diagnosis of the bronchogenic carcinoma. With longer survival of patients with disseminated tumors it is probable that new manifestations of those malignancies will be discovered. Acute appendicitis due to metastasis from a distant neoplasm should be considered in the differential diagnosis of right lower abdominal pain in the oncology patient.

Proliferation Markers and Their Uses in the Study of Endocrine Tumors

A growing body of literature supports the view that the proliferative activity (PA) of tumor cells is an important prognostic indicator for a variety of different tumors. We examined the role of PA in diagnosis and prediction or malignancy of endocrine tumors (ETs) of pituitary gland, pancreas, thyroid, parathyroid glands, adrenal glands, paraganglia, gastroenteric tract, and lung. The data in the literature indicate that the assessment of PA is not a diagnostic indicator of malignancy especially at the individual case level, whereas it can be useful for identifying subsets of malignant tumors with different aggressiveness potential, as well as for choosing therapeutic options in metatstatic lesions. We hope that, in the near future, multiparametric approaches including PA markers, cell growth and differentiation factors, and oncogenes will yield valuable information for diagnosis and prognosis of ETs also in individual cases.