Small-cell neuroendocrine carcinoma of the ampullary region. A clinicopathologic, immunohistochemical, and ultrastructural study of three cases

Neuroendocrine neoplasms of the duodenum, ampullary region, jejunum and ileum

Neuroendocrine neoplasms of the small intestine are some of the most frequently occurring along the gastrointestinal tract, even though their incidence is extremely variable according to specific sites. Jejunal-ileal neuroendocrine neoplasms account for about 27% of gastrointestinal NETs making them the second most frequent NET type. The aim of this review is to classify all tumors following the WHO 2019 classification and to describe their pathologic differences and peculiarities.

Four Neuroendocrine Tumor Types and Neuroendocrine Carcinoma of the Duodenum: Analysis of 203 Cases

BACKGROUND

Several types of neuroendocrine neoplasms (NENs) have been described in the duodenal tract, from low-grade tumors (NETs) to high-grade neuroendocrine carcinomas (NECs). A comprehensive analysis of histology, hormonal profile and prognostic parameters of a sufficiently large duodenal NEN series to cover all main kinds of neoplasms is however lacking.

METHODS

We collected a retrospective series of 203 duodenal wall and ampullary region NENs, from six specialized endocrine pathology centers. All were characterized histopathologically and histochemically, and 190 were followed for a median of 9 years.

RESULTS

Twenty-seven poorly differentiated NECs, mostly from the ampullary region, were identified and shown to lead to patient demise in a median of 10 months. Among 176 NETs, four subtypes were characterized, including 20 gastrinomas, 37 ampullary-type somatostatin-producing NETs (ASTs), 12 gangliocytic paragangliomas (GPs) and 106 nonfunctioning NETs (nfNETs). ASTs and GPs were mostly localized in the ampullary/periampullary region, while gastrinomas and nfNETs were mainly from the proximal duodenum. ASTs and gastrinomas showed high rates of local infiltration (especially lymphoinvasion and deep duodenal wall/pancreatic tissue invasion) and lymph node metastasis, while nfNETs had significantly lower and more size-dependent local invasive potential. Disease-specific survival differed significantly between NETs and NECs, though not among NET subtypes. NET cases with distant metastases (n = 23) were significantly associated with larger size, higher proliferative grade, lymphovascular invasion, deep invasion and local lymph node metastasis.

CONCLUSION

Our careful analysis of a large series of duodenal NENs identified five histologically and prognostically different histotypes of potential clinical relevance.

Extrapulmonary small cell carcinoma of lymph node: Pooled analysis of all reported cases

AIM

To study clinical outcomes and management of lymph nodes extrapulmonary small cell carcinoma (LNEPSCC).

METHODS

Herein, we perform a systematic search of published literature in the PubMed and EMBASE databases for studies describing LNEPSCC. For uniformity of reporting, LNEPSCC was staged as limited if it involved either single lymph node station or if surgery with curative intent had been undertaken. The disease was staged extensive if it involved two or more lymph node regions.

RESULTS

The systematic literature review yielded eight descriptions (n = 14) involving cervical, submandibular and inguinal lymph nodes. Eleven (64.7%) patients had limited disease (LD) and six (35.3%) had extensive disease (ED) at presentation. Chemotherapy (n = 6, 35.3%) or surgery (n = 4, 23.5%) were the most common form of treatment given to these patients. Complete response was achieved in 12 (70.6%) of the patients. Median (interquartile range) progression free survival and overall survival was 15 (7-42) mo and 22 (12.75-42) mo respectively. Of the three illustrative cases, two patients each had ED at presentation and achieved complete remission with platinum based combination chemotherapy.

CONCLUSION

LNEPSCC is a rare disease with less than 15 reported cases in world literature. Surgical resection with curative intent is feasible in those with LD while platinum based combination chemoradiation is associated with favorable outcomes in patients with ED. Prognosis of LNEPSCC is better than that of small cell lung cancer in general.

Endoscopic approach to the patient with benign or malignant ampullary lesions

Adenoma and adenocarcinoma are the most common ampullary lesions. Advances in diagnostic modalities including endoscopic ultrasonography and intraductal ultrasonography have provided useful information that aids in diagnosing and managing ampullary lesions. Endoscopic papillectomy can be a curative therapy for localized ampullary adenoma and have a role in the diagnosis of indeterminate ampullary lesions that may contain a hidden malignancy. However, the consensus on how and when to use endoscopic papillectomy has not been fully established. This article reviews the approach to the patient with benign or malignant ampullary lesion.

Histopathology of gastrointestinal neuroendocrine neoplasms

Gastrointestinal neuroendocrine neoplasms (GI-NENs) arise from neuroendocrine cells distributed mainly in the mucosa and submucosa of the gastrointestinal tract. In 2010, the World Health Organization (WHO) classification of NENs of the digestive system was changed, categorizing these tumors as grade 1 neuroendocrine tumor (NET), grade-2NET, neuroendocrine carcinoma (large- or small-cell type), or mixed adenoneuroendocrine carcinoma (MANEC). Such a classification is based on the Ki-67 index and mitotic count in histological material. For the accurate pathological diagnosis and grading of NENs, it is important to clearly recognize the characteristic histological features of GI-NENs and to understand the correct method of counting Ki-67 and mitoses. In this review, we focus on the histopathological features of GI-NENs, particularly regarding biopsy and cytological diagnoses, neuroendocrine markers, genetic and molecular features, and the evaluation of the Ki-67 index and mitotic count. In addition, we will address the histological features of GI-NEN in specific organs.

Classification and pathology of gastroenteropancreatic neuroendocrine neoplasms

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are composed of cells with a neuroendocrine phenotype. The old and the new WHO classifications distinguish between well-differentiated and poorly differentiated neoplasms. All well-differentiated neoplasms, regardless of whether they behave benignly or develop metastases, will be called neuroendocrine tumours (NETs), and graded G1 (Ki67 <2%) or G2 (Ki67 2-20%). All poorly differentiated neoplasms will be termed neuroendocrine carcinomas (NECs) and graded G3 (Ki67 >20%). To stratify the GEP-NETs and GEP-NECs regarding their prognosis, they are now further classified according to TNM-stage systems that were recently proposed by the European Neuroendocrine Tumour Society (ENETS) and the AJCC/UICC. In the light of these criteria the pathology and biology of the various NETs and NECs of the gastrointestinal tract (including the oesophagus) and the pancreas are reviewed.

Resectable pancreatic small cell carcinoma

Primary pancreatic small cell carcinoma (SCC) is rare, with just over 30 cases reported in the literature. Only 7 of these patients underwent surgical resection with a median survival of 6 months. Prognosis of SCC is therefore considered to be poor, and the role of adjuvant therapy is uncertain. Here we report two institutions' experience with resectable pancreatic SCC. Six patients with pancreatic SCC treated at the Johns Hopkins Hospital (4 patients) and the Mayo Clinic (2 patients) were identified from prospectively collected pancreatic cancer databases and re-reviewed by pathology. All six patients underwent a pancreaticoduodenectomy. Clinicopathologic data were analyzed, and the literature on pancreatic SCC was reviewed. Median age at diagnosis was 50 years (range 27–60). All six tumors arose in the head of the pancreas. Median tumor size was 3 cm, and all cases had positive lymph nodes except for one patient who only had five nodes sampled. There were no perioperative deaths and three patients had at least one postoperative complication. All six patients received adjuvant therapy, five of whom were given combined modality treatment with radiation, cisplatin, and etoposide. Median survival was 20 months with a range of 9–173 months. The patient who lived for 9 months received chemotherapy only, while the patient who lived for 173 months was given chemoradiation with cisplatin and etoposide and represents the longest reported survival time from pancreatic SCC to date. Pancreatic SCC is an extremely rare form of cancer with a poor prognosis. Patients in this surgical series showed favorable survival rates when compared to prior reports of both resected and unresectable SCC. Cisplatin and etoposide appears to be the preferred chemotherapy regimen, although its efficacy remains uncertain, as does the role of combined modality treatment with radiation.

Carcinoids and high-grade neuroendocrine carcinomas of the ampulla of vater: a comparative analysis of 139 cases from the surveillance, epidemiology, and end results program-a population based study

CONTEXT

Neuroendocrine tumors of the ampulla of Vater constitute a heterogeneous group of neoplasms clinically and morphologically. Because they are rare, little is known about their demographics and biologic behavior.

OBJECTIVE

To analyze the demographics and the 5- and 10-year relative survival rates of 139 patients with carcinoid tumors and high-grade neuroendocrine carcinomas of the ampulla.

DESIGN

Using data from National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program from 1973 to 2006, we analyzed the demographics, morphology, and survival of patients with carcinoids and neuroendocrine carcinomas of the ampulla.

RESULTS

SEER recorded 6081 cases of malignant neoplasms of the ampulla, of which 82 were carcinoid tumors and 57 were high-grade neuroendocrine carcinomas. Of these 57, 42 were neuroendocrine carcinomas, not otherwise specified; 9 were small cell carcinomas; and 6 were large cell neuroendocrine carcinomas. The incidence was higher in men than in women. Patients with carcinoid tumors were younger (mean age, 61.6 years) than those with high-grade neuroendocrine carcinomas (mean age, 67.5 years). Carcinoid tumors were smaller than high-grade neuroendocrine carcinomas. The frequency of lymph node metastasis was 28.5% for carcinoid tumors and 62% for high-grade neuroendocrine carcinomas. The 5- and 10-year relative survival rates of patients with carcinoid tumors were 82% and 71%, respectively. The 5- and 10-year relative survival rate of patients with high-grade neuroendocrine carcinomas was 15.7%.

CONCLUSIONS

Carcinoids of the ampulla of Vater are relatively rare. Carcinoids and high-grade neuroendocrine carcinomas of the ampulla are biologically and clinically similar to these tumors arising in other sites. Carcinoids were smaller and metastasized less frequently than high-grade neuroendocrine carcinomas.

Neuroendocrine tumors of the small bowels are on the rise: Early aspects and management

Neuroendocrine tumors of the small bowel are on the rise. In the US they have increased by 300%-500% in the last 35 years. At the same time their prognosis is much improved. Today, most neuroendocrine tumors (NETs) of the duodenum are detected "incidentally" and therefore recognized at an early stage. Duodenal NETs which are well differentiated, not larger than 10 mm and limited to the mucosa/submucosa can be endoscopically resected. The management of duodenal NETs ranging between 10 and 20 mm needs an interdisciplinary discussion. Endoscopic ultrasound is the method of choice to determine tumor size and depth of infiltration. Surgery is recommended for well-differentiated duodenal NET tumors greater than 20 mm, for localized sporadic gastrinomas (of any size) and for localized poorly differentiated NE cancers. Surgery is recommended for any ileal NET. Advanced ileal NETs with a carcinoid syndrome are treated with long-acting somatostatin analogs. This treatment significantly improves (progression-free) survival in patients with metastatic NETs of the ileum. For optimal NET management, tumor biology, type, localization and stage of the neoplasm, as well as the patient's individual circumstances have to be taken into account.

Large cell neuroendocrine carcinoma of the ampulla of vater with adenocarcinoma and squamous cell carcinoma components

A 73-year-old woman visited our hospital complaining of general fatigue and jaundice. Laboratory tests revealed an elevated total bilirubin, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and γ-glutamyltransferase. Computed tomography and magnetic resonance imaging demonstrated a mass lesion at the ampulla of Vater with dilatation of the common bile duct and main pancreatic duct. Percutaneous transhepatic cholangiography revealed dilatation of the bile duct and a negative filling defect due to the tumor. Pancreatoduodenectomy was performed. The specimen included an ulcerated firm tumor of the papilla Vater. The surface of the ampulla consisted of well-differentiated papillary adenocarcinoma, whereas the deep layer, such as submucosal or muscular layer, contained large cell neuroendocrine carcinoma and squamous cell carcinoma. Immunohistochemistry revealed that the large cell neuroendocrine carcinoma component was positive for chromogranin A, synaptophysin and CD56. The patient died from multiple liver and bone metastases 13 months after surgery. This is a very rare case of a large cell neuroendocrine carcinoma accompanied by adenocarcinoma and squamous cell carcinoma components.

Primary extra-ampullary duodenal neuroendocrine carcinoma in an adult male

A primary extra-ampullary duodenal neuroendocrine carcinoma was found in a 40-year-old man who presented with upper abdominal pain and weight loss. Duodenoscopy and hypotonic duodenography revealed a protruding fungating mass with luminal occlusion at the third part of the duodenum (D3). Although the metastatic work-up was normal, the tumor was inoperable intraoperatively, hence a palliative bypass was carried out followed by chemotherapy with 5-fluorouracil and leucovorin. Examination of the biopsy by immunohistochemistry and ultrastructural study revealed it to be neuroendocrine in nature, expressing synaptophysin, chromogranin and cytokeratin and containing dense core cytoplasmic granules. However, there was no evidence of clinical endocrinopathy. The present case emphasizes the need for better detection, further analysis and evaluation of such rare cases to identify their clinical course and effective treatment modalities.

Coexistence of small cell neuroendocrine carcinoma and villous adenoma in the ampulla of Vater

Small cell neuroendocrine carcinoma of the ampulla of Vater is extremely rare and different from the common ampullary adenocarcinoma. The ampullary adenoma is also a rare neoplasm and has the potential to develop an adenocarcinoma. Their coexistence has been rarely reported in the literature. We herein describe an unusual case of a small cell neuroendocrine carcinoma associated with a villous adenoma in the ampulla of Vater with emphasis on computed tomography (CT) and histopathological findings. We also discuss their clinical, histopathological and radiological features as well as possible histogenesis.

Coexistence of small cell neuroendocrine carcinoma and villous adenoma in the ampulla of Vater

Small cell neuroendocrine carcinoma of the ampulla of Vater is extremely rare and different from the common ampullary adenocarcinoma. The ampullary adenoma is also a rare neoplasm and has the potential to develop an adenocarcinoma. Their coexistence has been rarely reported in the literature. We herein describe an unusual case of a small cell neuroendocrine carcinoma associated with a villous adenoma in the ampulla of Vater with emphasis on computed tomography (CT) and histopathological findings. We also discuss their clinical, histopathological and radiological features as well as possible histogenesis.

Adenocarcinoma of the ampulla of Vater: T-stage, chromosome 17p allelic loss, and extended pancreaticoduodenectomy are relevant prognostic factors

OBJECTIVE

To evaluate the prognostic significance of different clinico-pathological and molecular factors, and to compare survival after standard and extended pancreaticoduodenectomy (PD) in ampulla of Vater adenocarcinoma (AVAC). There are discordant data on factors affecting prognosis, and hence therapeutic choices, in AVAC.

PATIENTS AND METHODS

Clinical-pathological factors were evaluated in 59 patients, subjected to PD for AVAC; in 42 subjects information on chromosome 17p and 18q allelic losses (LOH) and microsatellite instability (MSI) was also available. The association between survival and type of PD was investigated in the 25 patients operated between 1990 and 2001 (16 standard and nine extended).

RESULTS

The overall 5- and 10-year tumor-related survival rates were 46% and 33%, respectively. Sixteen patients had T-stages 1-2, 14 T-stage 3, and 29 T-stage 4 cancers. Chromosome 17p and 18q LOH were detected in 23 (55%) and 15 cases (36%), respectively, and in 12 cases (29%) coexisted. Five cases were MSI-positive (12%). At univariate analysis, poor survival was associated with cancer ulceration (P = 0.051), poor differentiation (P = 0.008), T-stage 4 (P < 0.001), nodal metastases (P = 0.004), chromosome 17p (P < 0.001) and 18q LOH (P = 0.002), and absence of MSI (P = 0.009). At multivariate analysis, only T-stage (P = 0.002) and 17p LOH (P = 0.001) were independent predictors of survival. All patients with MSI-positive cancers were long-survivors (>12 yrs), whereas only 30% of MSI-negative cancer patients survived at 5 years. Extended pancreaticoduodenectomy was associated with a 3-year disease-related survival higher than standard resection (83% vs 31%; P = 0.018).

CONCLUSION

MSI and chromosome 17p status allow to better define prognosis within ampullary cancers at the same stage. Surgery alone resulted curative in MSI-positive cancer patients, whereas it was inadequate in patients showing allelic losses, who might benefit from adjuvant therapy. In this observational study, extended PD was associated with increased survival compared to standard procedures.

Small-cell neuroendocrine carcinoma of the ampulla of Vater

We report a patient (an 80-year-old woman) with anemia and fecal occult blood, who had an emergency operation for carcinoma of the cecum (well-differentiated adenocarcinoma without local lymph node metastasis). Postoperative magnetic resonance cholangiopancreatography, cholangiography, and upper gastroduodenal endoscopy showed a tumor of the ampulla of Vater, and pylorus-preserving pancreatoduodenectomy was performed. Histology of the resected tumor was that of small-cell carcinoma, and immunohistochemistry showed positive staining for neuron-specific enolase, chromogranin A, and synaptophysin, confirming the neuroendocrine nature of the tumor. As the histology of the tumor was distinct from cecal carcinoma, and no tumors were found in other organs, the tumor was diagnosed as primary small-cell neuroendocrine carcinoma of the ampulla of Vater. The patient died due to multiple liver metastases of the carcinoma of the ampulla of Vater 7 months after the pancreatoduodenectomy. The clinical and morphological features of this disease have been reported in nine individuals previously.

High-Grade Neuroendocrine Carcinoma of the Ampulla of Vater

We describe the clinical and pathologic features of 14 cases of high-grade neuroendocrine carcinoma (HGNEC) of the ampulla of Vater classified according to WHO classification of lung tumors into small cell carcinoma (SCC, 6 cases) and large cell neuroendocrine carcinoma (LCNEC, 8 cases) types. The immunohistochemical findings were compared with those of 13 cases of primary poorly differentiated ampullary adenocarcinomas (PDACA) lacking neuroendocrine morphology. The mean age of 10 males and 4 females was 70 years. The mean tumor size was 2.5 cm. Ten of 13 patients had lymph node metastases (mean, 2.3 nodes involved). Documented sites of distant metastases included brain and liver. Overall, 64% of patients with ampullary HGNEC died of disease (mean follow-up, 14.5 months). Four patients had no evidence of disease after resection (mean, 20 months). Half of the tumors were associated with adenomas of the adjacent mucosa, 2 with high-grade dysplasia. Two HGNECs were combined with a conventional adenocarcinoma and another with a squamous cell carcinoma component. By immunohistochemistry, the HGNECs were positive for cytokeratins (AE1/AE3, 100%; Cam5.2, 67%; CK7, 87%; CK20, 38%), similar to the pattern found in PDACAs. p27 expression was lost in 1 case of HGNEC and in all PDACAs. Retinoblastoma (Rb) protein expression was lost in 60% of HGNECs and in none of the PDACA cases. In conclusion, HGNECs of the ampulla are rare (2%-3% of ampullary tumors in our material). The clinical course parallels that of their pulmonary counterparts and appears to be worse than that of locally advanced ampullary adenocarcinomas. The association with adenoma and or conventional adenocarcinoma components may suggest a common pathway in the initial carcinogenesis of these two types of tumors. Loss of Rb expression, a characteristic finding in pulmonary SCCs, is present in almost half of ampullary HGNECs. In contrast, p27 expression is lost in PDACAs and retained in most HGNECs. Thus, there are differences in the molecular phenotypes of these two types of ampullary carcinoma, supporting the distinction of poorly differentiated carcinomas with a neuroendocrine phenotype from those without.

Primary small-cell neuroendocrine carcinoma of the duodenum - a case report and review of literature

BACKGROUND

Small-cell neuroendocrine carcinoma in the duodenum is an extremely rare neoplasm with poor prognosis.

CASE PRESENTATION

A 57-year-old man presented with sudden onset gastrointestinal bleeding and fainting attacks. Duodenoscopy and hypotonic duodenography revealed a 3 x 3 cm protruding tumor with ulcerations situated opposite the ampulla of Vater in the second part of the duodenum. Local excision of the tumor was performed, followed by adjuvant chemotherapy with 5-fluoro uracil and leucovorin. Examination of the tumor by immunohistochemistry and electron microscopy indicated it to be neuroendocrine in nature, expressing synaptophysin and AE1/AE3, and containing dense core granules. The patient showed no sign of recurrence and has been disease-free for more than 48 months after surgery.

CONCLUSIONS

Most cases of small-cell neuroendocrine carcinoma in the duodenum show rapid progression of the disease, and even radical surgery with or without chemotherapy do not prevent death. We report a rare subtype of small-cell neuroendocrine carcinoma. This subtype appears to have a much better prognosis, and may be amenable to local excision, if the lesion is away from the ampulla of Vater.

Pancreatic polypeptide hypersecretion associated with a neuroendocrine carcinoma of the gallbladder

The authors report a case of a suspected pure pancreatic polypeptide-secreting neuroendocrine carcinoma of the gallbladder. The tumor was initially interpreted as an adenocarcinoma of the gallbladder, but was found to have a neuroendocrine component after review. The pathology supports the view that a primitive epithelial stem cell can express both epithelial and neuroendocrine characteristics and can differentiate into both an adenocarcinoma and a neuroendocrine carcinoma. Upon recurrence, the tumor produced symptoms due to local growth, but eventually metastasized and led to the death of the patient within 4 years. The patient was treated with chemoembolization followed by the long-acting somatostatin analog octreotide acetate. The high serum level of pancreatic polypeptide may have contributed to cholestasis and cholelithiasis. Earlier measurement of serum hormone levels and identification of high pancreatic polypeptide levels may have suggested the presence of residual tumor and led to closer follow-up, imaging studies, and therapy.

Primary adenocarcinoma of the duodenum in the elderly: clinicopathological and immunohistochemical study of 17 cases

Seventeen cases of primary duodenal adenocarcinoma occurring in the elderly (older than 65 years) were examined to clarify their clinicopathological features and biological behavior. The mean age was 77.4 years (range, 66-104), and there was no appreciable difference in the incidence between the sexes (female: male ratio, 8: 9). Thirteen patients had tumors located in the first portion of the duodenum, three in the second portion and one in the third portion. Grossly, there were three varieties of lesions: six polypoid, four flat-elevated and seven ulcerative-invasive. Sixteen cases showed well-differentiated adenocarcinoma, three of which were difficult to distinguish from adenoma, and one was poorly differentiated adenocarcinoma. Three of 16 tumors had poor differentiation in the invasive area, whereas mucosal lesions were well differentiated. Eight tumors had invaded the duodenal wall with occasional involvement of the pancreas. Immunohistochemistry demonstrated p53 protein overexpression in two intramucosal (22.2%) and five invasive (62.5%) cancers. In the intramucosal area the mean Ki-67-positive rate (PR) of the tumors with distant metastasis was significantly higher than that of the tumors without metastasis (46.0 vs 31.6%; P < 0.05), while there was no significant difference in the association between PR and gross feature or depth of the tumors. Clinical follow-up showed three of the five patients with invasive cancer died of carcinoma within 28 months. Compared with published data from other investigators, the results of the present study indicate a proximal shift of duodenal carcinoma in the elderly. Furthermore, it is concluded that invasive duodenal adenocarcinomas with high PR should be considered as potentially aggressive tumors, although their histology may indicate a high degree of differentiation.

Apparent renal cell carcinomas in tuberous sclerosis are heterogeneous: the identification of malignant epithelioid angiomyolipoma

Renal epithelial tumors (carcinoma and oncocytoma) have been reported with higher a frequency than expected in patients with the tuberous sclerosis complex. However, the recent identification of a monotypic, epithelioid variant of angiomyolipoma, closely simulating renal cell carcinoma, has cast doubt on the real frequency of carcinoma. Immunohistochemical analysis with a panel of antibodies, including melanogenesis marker HMB45, can discriminate between carcinoma and carcinoma-like angiomyolipoma. We studied five tumors previously reported as carcinoma and found that only one of them showed an immunohistochemical phenotype indicative of an epithelial tumor (Ker+, HMB45-). Three tumors exhibited a phenotype compatible with the monotypic epithelioid variant of angiomyolipoma (HMB45+, Ker-), and two of the three patients died of metastatic disease. The last patient had unusual clinical features, and the tumor was positive both for HMB45 and keratin. It is concluded that (1) renal cell carcinoma is less common in tuberous sclerosis complex than previously believed, (2) some cases called renal cell carcinoma probably represent a monotypic, epithelioid variant of angiomyolipoma, and (3) epithelioid angiomyolipoma is a potentially malignant tumor with invasion and metastases. These findings indicate that all reported renal carcinomas in tuberous sclerosis complex, therefore, must be reevaluated.

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.

Ultrastructural and immunocytochemical features of a case of neuroendocrine carcinoma developing in a prior ileostomy site

A patient who developed a mixed neuroendocrine carcinoma and adenocarcinoma at the site of a previous long-standing ileostomy is reported. The neuroendocrine features are documented by both ultrastructural and immunocytochemical findings. Carcinoma arising in an ileostomy site is rare but has been recorded in patients with long-standing ileostomies after colectomy for chronic inflammatory bowel disease, as in this patient. Neuroendocrine carcinoma developing in this setting apparently has not been described before, however.

Clear cell ("sugar") tumor of the lung is a lesion strictly related to angiomyolipoma--the concept of a family of lesions characterized by the presence of the perivascular epithelioid cells (PEC)

We report a comparative study of 3 clear cell tumors of the lung (CCTL) and 3 angiomyolipomas (AML) of the kidney. Morphological analysis shows that the cells of CCTL are identical to the perivascular epithelioid component of AML. Phenotypically they both consistently expressed melanoma-associated antigens recognized by Moabs HMB45 and HMSA-1, while they were negative for HMSA-5. A minority of cells also expressed S-100 protein, vimentin and actin. In addition, one case of CCTL showed mature adipose tissue entrapped in the proliferation, thus suggesting an intermediate form between CCTL and AML. Based on morphological and phenotypical similarities, it is suggested that CCTL and AML belong to the same family of lesions, characterized by the presence of a peculiar muscle cell, expressing different melanoma-associated antigens.

Small cell carcinoma of the ampulla of vater

Primary small cell carcinoma of the periampullary region is rare. Only four patients have been reported previously. The authors examined a patient with ampullary small cell carcinoma using a range of immunocytochemical stains. This tumor shows morphologic and neuroendocrine features similar to its pulmonary and extrapulmonary counterparts.

Small cell undifferentiated carcinoma of the pancreas. Report of a patient with tumor marker studies

BACKGROUND

Small cell undifferentiated carcinoma of the pancreas is a rare type of pancreatic neoplasm.

METHODS

The authors report the clinical and pathologic aspects of a patient with this malignant lesion and an extensive serologic and immunohistochemical survey of potential ectopically produced hormones or tumor markers.

RESULTS

Neuron-specific enolase (NSE) emerged as a tumor marker.

CONCLUSIONS

NSE could be valuable in the diagnosis and management of other patients with this rare disease.

The WHO Histological Classification of Tumors of the Gallbladder and Extrahepatic Bile Ducts. A commentary on the second edition

The second edition of the WHO Histological Classification of Tumors of the Gallbladder and Extrahepatic Bile Ducts is more comprehensive and detailed than the previous one. Advances in our understanding of dysplasia, carcinoma in situ, various lines of differentiation among the carcinomas, and the recognition of a variety of tumor-like lesions have resulted in more than three times as many entities in the current classification as in the previous one. The new edition should facilitate pathologic, epidemiologic, and therapeutic comparisons.

An immunohistochemical and ultrastructural study of case of small-cell neuroendocrine carcinoma in the ampullary region of the duodenum

One case of small-cell neuroendocrine carcinoma in the ampullary region of the duodenum is reported. The histological appearance of the tumor was identical to pulmonary small-cell carcinoma. Neuroendocrine differentiation was demonstrated immunohistochemically by positive immunoreaction for neuron specific enolase, Leu-7 and chromogranin, and ultrastructurally by the presence of scanty dense-core neurosecretory type granules. Small-cell neuroendocrine carcinoma in the ampulla of Vater is extremely rare. To our knowledge, this is the sixth reported case.

Small cell carcinoma of the gallbladder combined with adenocarcinoma

A rare case of small cell carcinoma (SCC) of the gallbladder combined with adenocarcinoma is reported. The patient was a 70-year-old Japanese man, who died of the disease shortly after the onset of symptoms. Autopsy disclosed a small tumor (1.0 cm in longest diameter) in the fundus of the gallbladder, with widespread metastasis. Histochemically, the tumor cells showed negative reactions for argyrophilic and argentaffin stainings, a weak immunohistochemical reaction only for neuron-specific enolase, and negative reactions for all of the other neurosecretory markers used, including neurofilament, chromogranin, somatostatin, gastrin and leu-7. However, electron microscopic examination revealed a few typical neurosecretory granules (NSG) in the cytoplasm of some tumor cells. We suggest that: 1. The presence of NSG in the cytoplasm of tumor cells is the most reliable diagnostic criterion for SCC. 2. SCC, at least the combined type, arises from a multipotential stem cell.