H2A.Z overexpression suppresses senescence and chemosensitivity in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most intractable and devastating malignant tumors. Epigenetic modifications such as DNA methylation and histone modification regulate tumor initiation and progression. However, the contribution of histone variants in PDAC is unknown. Here, we demonstrated that the histone variant H2A.Z is highly expressed in PDAC cell lines and PDAC patients and that its overexpression correlates with poor prognosis. Moreover, all three H2A.Z isoforms (H2A.Z.1, H2A.Z.2.1, and H2A.Z.2.2) are highly expressed in PDAC cell lines and PDAC patients. Knockdown of these H2A.Z isoforms in PDAC cell lines induces a senescent phenotype, cell cycle arrest in phase G2/M, increased expression of cyclin-dependent kinase inhibitor CDKN2A/p16, SA-β-galactosidase activity and interleukin 8 production. Transcriptome analysis of H2A.Z-depleted PDAC cells showed altered gene expression in fatty acid biosynthesis pathways and those that regulate cell cycle and DNA damage repair. Importantly, depletion of H2A.Z isoforms reduces the tumor size in a mouse xenograft model in vivo and sensitizes PDAC cells to gemcitabine. Overexpression of H2A.Z.1 and H2A.Z.2.1 more than H2A.Z.2.2 partially restores the oncogenic phenotype. Therefore, our data suggest that overexpression of H2A.Z isoforms enables cells to overcome the oncoprotective barrier associated with senescence, favoring PDAC tumor grow and chemoresistance. These results make H2A.Z a potential candidate as a diagnostic biomarker and therapeutic target for PDAC.

Hyaline vascular Castleman's disease involving the biliary tract

We report a case of Castleman's Disease (CD), hyaline vascular subtype involving the biliary tract with obstruction. A 43 year old man presented with a 5 week history of abdominal and back pain with biliary obstructive symptoms. He was jaundiced with persistently high LFTs. Radiological investigation revealed a stricture in the extrahepatic biliary tract. The clinical impression at the time was of sclerosing cholangitis with bile duct cholangiocarcinoma. A Whipple's procedure was performed. Histology and immunohistochemistry supported the histologic diagnosis of CD of hyaline vascular subtype. There was no evidence of disease elsewhere and the patient was disease free after a 6 year follow-up. Our case describes the hyaline vascular subtype of CD, a relatively rare disease occurring in a previously undescribed location.

[Pseudohyperplastic carcinoma with xanthomatous changes: a neoplasm mimicking glandular hyperplasia of the prostate]

INTRODUCTION AND OBJECTIVES

Varieties of prostatic adenocarcinoma whose architectural and cytological appearance mimicked benign lesions have been reported in recent decades. Such neoplasms include xanthomatous (foamy) carcinoma and pseudohyperplastic carcinoma. We recently studied five carcinomas showing a cytoarchitectural combination of both neoplasms which were confused with benign glandular proliferations.

METHODS

Five cases (1.8%) of pseudohyperplastic carcinoma showing xanthomatous changes were selected from a total of 280 biopsies showing prostate carcinoma. Glandular prostatic hyperplasia was originally diagnosed in four of such cases.

RESULTS

Patient age ranged from 54 and 78 years (mean, 64 years). All patients had high prostate-specific antigen levels, and digital rectal examination showed abnormalities in four of them. Neoplasms showed minimal atypia and consisted of mid- to large-sized glands arranged in nests resembling hyperplastic nodules. Glands showed papillary projections, infoldings, and undulations. Most nuclei were basal, small and hyperchromatic, and nucleomegaly was only seen in two biopsies in isolated histological fields. Several useful criteria for diagnosis of acinar carcinoma, such as perineural infiltration, mitosis, crystalloids, blue secretions, and prostatic intraepithelial neoplasm, were absent.

CONCLUSIONS

Prostatic carcinoma with a pseudohyperplastic pattern and xanthomatous changes mimics hyperplastic glands. Timely detection is critical to avoid treatment delay.

Allelic losses at 3p and 11p are detected in both epithelial and stromal components of cervical small-cell neuroendocrine carcinoma

Microdissected epithelial and stromal cells from 15 cervical small-cell carcinoma patients and 9 healthy control subjects were assessed for loss of heterozygosity with polymorphic DNA markers at chromosomes 3p and 11p. Among malignant lesions assessed with 7 markers at 3p, 21 allelic losses were detected from 193 informative samples. Of losses, 20 were in epithelial and 1 was in normal-appearing stromal cells. Among losses in epithelial cells, 16 were from 44 samples informative for 3 markers within 3p21.2-p14.2 (0.36 loss/sample), whereas only 4 were from 54 samples informative for 4 markers outside the region (0.09 loss/sample), suggesting a "hot spot" of genetic alterations within 3p21.2-p14.2. Among malignant lesions assessed with 2 markers within 11p14-p12, 15 losses were seen in 52 informative samples. Of losses, 10 were in epithelial and 5 were in normal-appearing stromal cells. Of 10 epithelial samples showing losses within 11p14-p12, 8 also displayed losses within 3p21.2-p14.2, suggesting a concurrent involvement of these loci in tumor development or progression. The five losses in stromal cells were in four cases that showed no loss in epithelial cells with same markers, suggesting that stromal cells might play initiative roles in tumor development.

Metaplastic lesions of the extrahepatic bile ducts: a morphologic and immunohistochemical study

Although metaplastic changes can occur in the extrahepatic bile ducts, a detailed morphologic study of these lesions has not been done. We examined the bile duct mucosa in 42 pancreaticoduodenectomy specimens, 32 with neoplastic lesions and ten with inflammatory lesions of the extrahepatic bile ducts, to assess the prevalence and type of metaplastic lesions. For comparison, the common bile ducts from 10 autopsy cases were reviewed. Twenty of the 42 total cases (48%), 13 of the 32 neoplastic cases (40%), and 7 of the 10 inflammatory cases (70%) had metaplastic changes. Pyloric gland metaplasia was the most common type (16/20 cases; 80%), whereas intestinal metaplasia was seen in 1/20 cases (5%). A combination of pyloric gland and intestinal metaplasia occurred in 2/20 cases (10%), and squamous metaplasia plus the above-mentioned two types of metaplasia was seen in 1/20 cases (5%). None of the normal common bile ducts obtained from ten autopsies had metaplastic changes. Endocrine cells were identified in nine (56%) of 17 metaplastic lesions. In contrast, endocrine cells within the intramural glands were seen in only 2 of the 10 normal common bile ducts. Although a significant proportion of carcinomas (6/13 cases) was in close proximity to areas of metaplasia, we were unable to find dysplastic foci within the metaplastic glands or the metaplastic surface epithelium. Reactive atypical cells involved the surface biliary epithelium and intramural glands and were associated with inflammation and metaplastic changes. The presence of goblet, mucinous, squamous, and reactive atypical cells in association with hyperplasia of intramural glands in frozen sections or small biopsy specimens may be mistaken for malignancy; hence, recognition of these lesions is of diagnostic importance.

Expression of protein gene product 9.5 in epithelioid and conventional malignant peripheral nerve sheath tumors

CONTEXT

Due to the frequent lack of S100 protein expression in malignant peripheral nerve sheath tumors (MPNSTs), especially the epithelioid variant, these tumors are difficult to diagnose without the aid of electron microscopy or a clinical history of neurofibromatosis.

METHODS

Protein gene product 9.5 (PGP9.5), a broad neural marker, is expressed in nerve fibers and neurons of both the peripheral and central nervous systems. We compared its expression to that of S100 protein in 16 cases of MPNST. As controls, 6 monophasic synovial sarcomas, 9 leiomyosarcomas, and 5 dermatofibrosarcoma protuberans were included.

RESULTS

Expression of PGP9.5 was seen in 15 MPNSTs, with 3 to 4+ positivity in the majority of the cases. Ten cases, 2 epithelioid and 8 conventional MPNSTs, were reactive with PGP9.5, but were negative for S100 protein. Five cases were immunoreactive for both S100 protein and PGP9.5. One case was negative for PGP9.5 but demonstrated focal S100 protein positivity. Expression of PGP9.5 was seen in 4 of 6 synovial sarcomas, 3 of 9 leiomyosarcomas, and none of 5 dermatofibrosarcoma protuberans.

CONCLUSION

Although PGP9.5 is not a specific marker for MPNST, it is a more sensitive marker than S100 protein (94% vs 38%). When there is a lack of S100 protein expression and a broad panel of immunostains, such as cytokeratin, epithelial membrane antigen, and smooth muscle actin, yields only focal or equivocal staining, PGP9.5 is a useful diagnostic adjunct in confirming the neural origin of a spindle cell sarcoma.

Clear cell carcinoid tumor of the gallbladder: another distinctive manifestation of von Hippel-Lindau disease

We describe a morphologically distinctive carcinoid tumor of the gallbladder that occurred in a 38-year-old man with von Hippel-Lindau (VHL) disease. The carcinoid tumor was composed predominantly of lipid-containing clear cells arranged in nests and tubules with pagetoid spread into the biliary epithelium and was interpreted as metastatic renal cell carcinoma. The neoplastic cells showed diffuse immunoreactivity for chromogranin, synaptophysin, cytokeratins (cytokeratin 7 and AE1/AE3) and, unexpectedly, for inhibin, but were negative for monoclonal carcinoembryonic antigen, serotonin and a variety of peptide hormones. This clear cell carcinoid tumor of the gallbladder was histologically similar to the recently described clear cell endocrine pancreatic tumor associated with VHL. Four cases of the latter tumor, which were also inhibin positive showed, in addition, focal and variable reactivity for the pancreatic hormones. Two classical carcinoid tumors of the gallbladder, two renal cell carcinomas associated with VHL and 11 of 13 sporadic endocrine pancreatic tumors (not associated with VHL) did not show immunoreactivity for inhibin. Inhibin appears to be an immunohistochemical marker for gallbladder clear cell carcinoid and clear cell endocrine pancreatic tumors associated with VHL and is a useful tool to distinguish these tumors from metastatic renal cell carcinoma. However, the basis for the inhibin positivity in these endocrine tumors is unknown.

Nasopharyngeal gangliocytic paraganglioma

Gangliocytic paraganglioma (GP) is a rare neoplasm described almost exclusively in the gastrointestinal tract, especially the periampullary region. However, several examples have been reported at various sites, including the stomach, jejunum, and appendix. Herein we report a case of GP involving the nasopharynx. To our knowledge, this is the first report of GP at this site. A 44-year-old woman presented with headaches and symptoms of fullness and pressure related to mass effect. An initial endoscopic biopsy was followed by surgical excision of the nasopharyngeal mass. The triphasic tumor fulfilled the morphologic and immunohistochemical criteria for GP. The histogenesis of GP is uncertain, and the current belief is that it arises from the embryonic ventral pancreas. This concept is based largely on the location of most cases, which is along the embryologic migration route of the ventral pancreas, as well as the expression of pancreatic polypeptide by the tumor. The nasopharyngeal location of our case clearly refutes the pancreatic origin of GP. We propose that the tumor probably arises from totipotential adult stem cells, which in the right microenvironment differentiate along nonnative cell lineages.

Atypical bile duct adenoma, clear cell type: a previously undescribed tumor of the liver

A variable proportion of bile duct adenomas of the liver are still confused with metastatic well-differentiated adenocarcinoma by surgeons and pathologists. We present here three examples of previously undescribed primary hepatic bile duct tumors that were composed almost entirely of clear cells that closely mimicked metastatic renal cell carcinoma. They were interpreted as atypical bile duct adenomas and occurred in two males and one female whose ages ranged from 25 to 64 years. All three tumors were incidental findings and measured from 0.8 to 1.1 cm. The clear neoplastic cells showed mild nuclear atypia and no mitotic activity. They were arranged in tubules and nests that focally infiltrated the hepatic parenchyma. For comparison, a case of clear cell cholangiocarcinoma and 13 conventional bile duct adenomas were examined. The clear cell cholangiocarcinoma was larger (6.0 cm) and had the tubular pattern of conventional cholangiocarcinoma and an abundant desmoplastic stroma. The clear cells of this tumor exhibited greater nuclear atypia and increased mitotic activity. All three atypical bile duct adenomas expressed cytokeratin (CK) 7, p53 protein, epithelial membrane antigen (EMA), and carcinoembryonic antigen (CEA); they were negative for CK20, vimentin, Hep Par 1, chromogranin, and prostatic specific antigen (PSA) and exhibited less than 10% of Ki-67-positive nuclei. One atypical bile duct adenoma displayed luminal immunoreactivity for villin. With the exception of Ki-67 reactivity, the 13 conventional bile duct adenomas and the clear cell cholangiocarcinoma had essentially a similar immunohistochemical profile as that of the atypical clear cell bile duct adenomas. The absence of an extrahepatic primary tumor, the histologic features, the immunohistochemical profile, and the fact that all patients are symptom-free 2 months to 18 years after wedge liver biopsy support the interpretation of atypical clear cell bile duct adenoma. The differential diagnosis with clear cell hepatocellular carcinoma and metastatic clear cell carcinomas is discussed.

Primary mammary small-cell carcinoma: a molecular analysis of 2 cases

Primary small-cell carcinoma of the breast is an exceedingly rare variant of breast carcinoma whose genetic profile has not been previously investigated. We report the molecular features of 2 cases of small-cell carcinoma of the breast: 1 with an adjacent intraductal carcinoma, and 1 with prior pleomorphic lobular carcinoma in situ. Laser capture microdissection followed by loss of heterozygosity (LOH) analysis revealed identical molecular alterations at multiple chromosomal regions, including BRCA-1, BRCA-2, p53, and retinoblastoma gene loci, in 1 case of small-cell carcinoma and its adjacent intraductal component. Additionally, LOH in 1 or both small-cell carcinomas was detected at 3p, 4q31.2-qter, 8p21-24, 11q13 (MEN-1 locus), 11q23.3, 11q24.1-25, 16q24.1 (H-cadherin locus), and 17q25. The results of our molecular analysis suggest that genetic changes in mammary small-cell carcinoma resembled those seen in both invasive ductal carcinomas and pulmonary small-cell carcinoma. Second, mammary small-cell carcinoma is clonally related to ductal carcinoma in situ and might represent an example of divergent differentiation occurring in a multipotential neoplastic stem cell.

Solitary cylindroma (dermal analog tumor) of the breast: a previously undescribed neoplasm at this site

The authors report a previously undescribed small, well-demarcated breast tumor similar to a dermal cylindroma in a 63-year-old woman. The tumor was an incidental finding in a lumpectomy specimen for infiltrating lobular carcinoma. The cylindroma was surrounded by normal-appearing breast parenchyma and had the typical "jigsaw" pattern of epithelial basaloid islands. The islands showed focal squamous and myoepithelial differentiation. A notable number of reactive dendritic Langerhans cells permeated the epithelial cell islands, a feature considered to be characteristic of dermal cylindroma. There was also ductal differentiation. Thick bands of hyaline periodic acid-Schiff (PAS) stain and collagen IV-positive basement membrane material bordered the cell islands, and PAS-collagen IV-positive hyaline globules were seen within the cell islands. There was no nuclear pleomorphism or mitotic figures. The cylindroma did not express gross cystic disease fluid protein 15, carcinoembryonic antigen, estrogen and progesterone receptors, or cytokeratin 20 (CK20). There was diffuse and strong immunoreactivity to CK AE1/AE3, and focal reactivity for CK7 and smooth muscle actin. Cylindroma of the breast should be distinguished from adenoid cystic carcinoma and basal cell carcinoma. Although clearly epithelial, the exact histogenesis and cell phenotype of this unusual dermal type cylindroma of the breast are unknown.

Pancreatic intraepithelial neoplasia: a new nomenclature and classification system for pancreatic duct lesions

Proliferative epithelial lesions in the smaller caliber pancreatic ducts and ductules have been the subject of numerous morphologic, clinical, and genetic studies; however, a standard nomenclature and diagnostic criteria for classifying these lesion have not been established. To evaluate the uniformity of existing systems for grading duct lesions in the pancreas, 35 microscopic slides with 35 representative duct lesions were sent to eight expert pathologists from the United States, Canada, and Europe. Kappa values for interobserver agreement could not be calculated initially because more than 70 different diagnostic terms were used by the eight pathologists. In several cases, the diagnoses rendered for a single duct lesion ranged from "hyperplasia," to "metaplasia," to "dysplasia," to "carcinoma in situ." This review therefore demonstrated the need for a standard nomenclature and classification system. Subsequently, during a working group meeting, the pathologists agreed to adopt a single standard system. The terminology pancreatic intraepithelial neoplasia (or PanIN) was selected, and diagnostic criteria for each grade of PanIN were established (http://pathology.jhu.edu/pancreas_panin). This new system was then evaluated by having the eight pathologists rereview the original 35 cases. Only seven different diagnoses were rendered, and kappa values of 0.43, 0.14, and 0.42 were obtained for PanINs 1, 2, and 3 respectively. Cases assigned other diagnoses (e.g., squamous metaplasia) collectively had a kappa value of 0.41. These results show both the potential of the classification system, and also the difficulty of classifying these lesions even with a consistent nomenclature. However, even when there is lack of consensus, having a restricted set of descriptions and terms allows a better understanding of the reasons for disagreement. It is suggested that we adopt and apply this system uniformly, with continued study of its reliability and use, and possibly further refinement. The acceptance of a standard classification system will facilitate the study of pancreatic duct lesions, and will lead ultimately to a better understanding of their biologic importance.

Small cell carcinoma of the gallbladder: a clinicopathologic, immunohistochemical, and molecular pathology study of 12 cases

Small cell carcinomas of the gallbladder are unusual neoplasms that have been characterized only recently. The authors describe the clinical, histopathologic, immunohistochemical, and molecular features of 12 small cell carcinomas of the gallbladder. The mean age at diagnosis was 69 years, and the male-to-female ratio was 5:7. The neoplasms had an average size of 3 cm, and 90% showed invasion of the muscularis propria and perimuscular connective tissue. Seventy-five percent of the carcinomas had metastasized or extended locally beyond the gallbladder at surgery. Survival was uniformly poor, with a mean survival of 10.7 months (range, 3-25 months). Half the small cell carcinomas were combined with other neoplasms. Four had foci of adenocarcinoma, one contained areas of squamous differentiation, and another had a component of carcinosarcoma. Immunohistochemical analysis showed focal reactivity for chromogranin (six of six cases), neuron-specific enolase (six of six cases), and Leu-7 (three of three cases). The molecular changes in small cell carcinomas were similar to those of adenocarcinomas occurring at this site, with a high frequency of p53 (75%) and p16INK4a (33%) abnormalities, and a low frequency of deleted in pancreatic carcinoma-4 inactivation (0%) and K-ras codon 12 mutations (17%). In contrast to pulmonary small cell carcinomas, p16INK4a function appears to be abrogated more frequently in these carcinomas.

Clear cell endocrine pancreatic tumor mimicking renal cell carcinoma: a distinctive neoplasm of von Hippel-Lindau disease

The dominantly inherited von Hippel-Lindau disease is characterized by clear cell neoplasms in various organs including the kidney and pancreas. Determination of primary versus metastatic lesion in this setting can be a diagnostic dilemma. The authors present five cases of clear cell endocrine pancreatic tumor (EPT) closely mimicking renal cell carcinomas in five patients with a family history or histologic evidence of von Hippel-Lindau disease. In fact, two of these tumors were confused with metastatic renal cell carcinoma by fine-needle aspiration. All five tumors had a component of clear cells arranged in nests, cords, and tubules with central hemorrhage separated by thin-wall vessels resembling renal cell carcinoma. However, these tumors also exhibited cords and festoons and a gyriform pattern suggestive of an endocrine neoplasm, and expressed chromogranin and synaptophysin. Vascular invasion was identified in four tumors, one of which metastasized. The concurrent primary renal cell carcinomas and the multicentric microcystic adenomas found in three patients did not show reactivity for the neuroendocrine markers. Focal clear cell change was noted in only one of 29 endocrine pancreatic tumors arising in patients without von Hippel-Lindau disease. Eleven metastatic renal cell carcinomas in the pancreas did not show immunoreactivity with the endocrine markers. Clear cell EPTs closely mimicking renal cell carcinoma are distinctive neoplasms of von Hippel-Lindau disease. In contrast to clear cell EPT, metastatic renal cell carcinoma does not express neuroendocrine markers and lacks neurosecretory granules by electron microscopy. Von Hippel-Lindau disease should be strongly suspected in patients with renal cell carcinoma, clear cell EPT, and multifocal microcystic serous adenomas.

Immunoreactivity for hepatocyte paraffin 1 antibody in hepatoid adenocarcinomas of the gastrointestinal tract

Hepatocyte paraffin 1 (Hep Par 1) is a monoclonal antibody considered almost specific for normal and neoplastic hepatocytes, that can be used on formalin-fixed paraffin-embedded tissues. Hep Par 1 reactivity has been demonstrated consistently in hepatocellular carcinomas and hepatoblastomas but only rarely in cholangiocarcinomas and metastatic tumors to the liver. Although its role as a marker of hepatocytic differentiation in primary liver tumors has been studied extensively, Hep Par 1 expression has not been explored in extrahepatic lesions, especially rare adenocarcinomas with hepatoid morphologic features. We studied 7 hepatoid adenocarcinomas of the gastrointestinal tract (6 gastric and 1 from the gallbladder) for Hep Par 1 immunoreactivity. Focal Hep Par 1 expression was seen in 6 of 7 tumors. These hepatoid adenocarcinomas also showed reactivity for alpha-fetoprotein and carcinoembryonic antigen. The presence of Hep Par 1 reactivity in extrahepatic hepatoid adenocarcinomas underscores the fact that Hep Par 1 expression is not unique to primary hepatocellular neoplasms. Adenocarcinomas with hepatoid features must be considered in the differential diagnosis of Hep Par 1-positive lesions.

Poorly differentiated follicular thyroid carcinoma with rhabdoid phenotype: a clinicopathologic, immunohistochemical and electron microscopic study of two cases

Poorly differentiated thyroid carcinomas with follicular cell phenotype are not well defined. Different diagnostic criteria have been employed for these tumors, including solid growth, nodular, trabecular, and insular patterns. Cytologic features, such as a predominance of tall and columnar cells, have been considered to be diagnostic of poorly differentiated carcinoma. However, there is no agreement among surgical pathologists regarding morphologic criteria for poorly differentiated thyroid carcinoma. We report two unique thyroid neoplasms that we interpreted as poorly differentiated follicular carcinomas. Nodular, trabecular, and sheetlike patterns predominated in both tumors. They were composed of cells that were focally immunoreactive for thyroglobulin and had large vesicular nuclei with prominent nucleoli. A variable number of cells showed rhabdoid phenotype. The rhabdoid inclusions did not stain for thyroglobulin but contained whorls of intermediate filaments that were vimentin positive. There were foci of necrosis and numerous mitotic figures. Both patients were adults and died with multiple pulmonary metastases. The presence of rhabdoid cells in poorly differentiated follicular carcinomas broadens the spectrum of tumors with rhabdoid phenotype. More cases are needed to determine whether the rhabdoid phenotype is a marker for poorly differentiated follicular carcinoma as well as an independent adverse prognostic factor.

Carcinoid tumors of the extrahepatic bile ducts: a study of seven cases

The authors report seven patients with carcinoid tumors of the extrahepatic bile ducts (EHBDs). All patients were women, with an average age at diagnosis of 49.8 years (range, 37-67 yrs). The most common presenting symptom was painless jaundice with or without pruritus. Although one patient had peptic ulcer disease before the onset of obstructive jaundice, none had systemic endocrine manifestations. These neoplasms were most often located in the common bile duct. Grossly, the carcinoid tumors were usually nodular and poorly demarcated, and ranged from 1.1 to 2.7 cm in size. Only one of the neoplasms was polypoid. Microscopically, the tumors had a trabecular or nesting pattern with occasional tubule formation, and were composed of relatively small cells with granular chromatin. All of the neoplasms expressed chromogranin and two expressed synaptophysin. Three expressed serotonin and two of the three were also immunoreactive for pancreatic polypeptide or somatostatin. Two tumors were focally positive for gastrin and one of these two tumors was also positive for serotonin and pancreatic polypeptide. All seven carcinoid tumors showed no immunoreactivity for p53, and assays for p53 loss of heterozygosity analysis were negative in two, suggesting that p53 mutations do not play a role in the pathogenesis of EHBD carcinoids. A mutation in codon 12 of K-ras was found in one carcinoid tumor whereas two of two showed immunoreactivity for Dpc4 protein. In view of the small number of carcinoids studied, the importance of these findings in the pathogenesis of these tumors is unclear. Ultrastructural examination of three of the tumors revealed numerous membrane-bound, round neurosecretory granules. Clinically, these lesions had an indolent course. Even in the presence of lymph node metastases (noted in two patients), all of the patients remained disease free 2 to 11 years (average follow up, 6.6 yrs) after segmental resection or pancreaticoduodenectomy (Whipple's procedure). Because carcinoid tumors of the EHBD are of low malignant potential, they should be separated from the more common adenocarcinomas in this location.

Hyalinizing clear-cell carcinoma of salivary glands in fine-needle aspiration

Hyalinizing clear-cell carcinoma (HCCC) is a recently described distinctive salivary gland neoplasm. Because of its cytoplasmic clearing and the bland nuclear features, HCCC resembles other tumors. The authors describe the cytomorphologic features of four cases of HCCC in fine-needle aspirates (FNA) and discuss the differential diagnosis. Fine-needle aspirates from 4 patients with primary HCCC of minor salivary glands were reviewed. Smears were stained with Diff-Quik and Papanicolaou stains. The cytologic features of the epithelial and the stromal components were analyzed. Cell blocks were prepared, and findings were correlated with prior or subsequent surgical specimens in each case. The smears contained numerous cohesive small and large epithelial cell groups and sheets which had sharp outlines and showed focal nuclear overlapping. The cells had uniform round to ovoid nuclei, granular chromatin, and small nucleoli. The abundant, well-defined cytoplasm was clear in many cells but denser in others. No myoepithelial cells or hyaline globules were identified. HCCC seems to have characteristic cytomorphologic findings on FNA smears. Because these cytologic features are not specific, and overlap with those of a number of salivary gland neoplasms that contain clear cells, a high level of suspicion, clinico-pathologic correlation, and examination of cell blocks are necessary to suggest the diagnosis. A diagnosis of HCCC by FNA was suspected in 3 of the 4 cases reported here.

Stromal tumor of the gallbladder with phenotype of interstitial cells of Cajal: a previously unrecognized neoplasm

We report a small, well-demarcated stromal tumor of the gallbladder in a 69-year-old woman. The tumor and associated cholelithiasis led to chronic cholecystitis symptoms. The wall of the gallbladder contained a 2.4-cm hypocellular nodule composed of bland spindle-shaped cells that were immunoreactive for vimentin, CD34, and CD117. With the latter antibody, which stains interstitial cells of Cajal (ICC), the neoplastic cells appear fusiform with elongated bipolar projections or dendritic-like cytoplasmic projections. The gallbladder wall adjacent to the tumor contained numerous CD117-positive cells in close contact with the normal smooth muscle cells, whereas two of 10 gallbladders with minimal chronic cholecystitis showed only a few CD117-positive cells. These findings provide evidence that this stromal tumor of the gallbladder shows ICC differentiation similar to some stromal tumors of the gut. The presence of numerous ICC in the uninvolved gallbladder wall suggests that this tumor might have evolved through hyperplasia of ICC.

Large cell neuroendocrine carcinoma of the gallbladder: report of two cases

We report two cases of primary large cell neuroendocrine carcinoma (LCNEC) of the gallbladder, which, to the best of our knowledge, represent the first description of this entity. One of the tumors consisted entirely of LCNEC, whereas the second tumor was composed of LCNEC and the more common intestinal-type adenocarcinoma. Both tumors were morphologically similar to their pulmonary counterpart and were characterized by large cells with prominent nucleoli, coarse chromatin, and a high mitotic rate. The cells showed an organoid growth pattern with rosette formation and frequent areas of necrosis. Panendocrine markers were expressed in a variable proportion of tumor cells in both cases, and one of the cases also showed focal positivity for type 2 somatostatin receptors. One of the tumors followed a rapidly fatal course despite aggressive surgical treatment and chemotherapy administration, and the second patient is still alive and disease-free 12 months after surgery. The description of these two cases of LCNEC of the gallbladder is significant for two reasons. From an academic standpoint, we now know that all the neuroendocrine tumors described in other organs can arise de novo in the gallbladder. More importantly, however, the recognition of this rare tumor type carries important clinical implications in regard to the use of chemotherapeutic agents and supplemental treatments (for example, somatostatin analogs).

Loss of Dpc4 expression in colonic adenocarcinomas correlates with the presence of metastatic disease

DPC4 is a candidate tumor suppressor gene on chromosome 18q21, a region that shows high frequencies of allelic losses in pancreatic and colorectal adenocarcinomas. Biallelic inactivation of DPC4 has been reported in half of pancreatic cancers, but are relatively infrequent in other tumor types. The role of DPC4 inactivation in colorectal neoplasms has not been fully characterized. An immunohistochemical assay for Dpc4 protein expression has been recently developed and shown to be a sensitive and specific surrogate for alterations in the DPC4 gene. In this study we examined the expression of Dpc4 protein in formalin-fixed archival tissue from 83 colorectal lesions, including 19 adenomas and 64 sporadic adenocarcinomas (11 stage I, 13 stage II, 17 stage III, and 23 stage IV cancers). None of the adenomas or stage I adenocarcinomas showed loss of Dpc4 expression, whereas one of 13 (8%) stage II, one of 17 (6%) stage III, and five of 23 (22%) of stage IV cancers showed loss of Dpc4 expression. There was a borderline significant difference in loss of Dpc4 reactivity in colorectal tumors with distant metastasis at presentation (22%) versus primary tumors without distant metastasis (5%) (Fisher's exact test, P = 0.05; chi(2) = 0.04). Poorly differentiated histology or status of pericolonic lymph nodes did not affect Dpc4 expression. Alterations in DPC4 are involved in the progression of a subset of colorectal carcinomas, especially those that present with advanced disease. In the sequential pathogenesis of colorectal tumors, inactivation of DPC4 is likely to be a late event.

Noninvasive and minimally invasive papillary carcinomas of the extrahepatic bile ducts

BACKGROUND

Adenocarcinomas of the extrahepatic bile ducts (EBD) are uncommon neoplasms that are morphologically heterogenous and associated with a poor prognosis. Papillary carcinomas of the EBD, however, appear to follow a much less aggressive clinical course.

METHODS

The authors reviewed the clinical records of nine patients with papillary carcinoma of the EBD, analyzed the microscopic features, and selected immunohistochemical reactivity (p53 and MIB-1) that might correlate with patient survival.

RESULTS

Six patients were male and three were female, with a mean age of 65 years (range, 48-83 years). The clinical presentation of disease in these patients was similar to that reported for conventional adenocarcinoma of EBD. According to their cell phenotypes, these papillary carcinomas were classified as biliary type (7 cases) and intestinal type (2 cases). Most were located in the common bile duct and were well differentiated (7 cases). Five showed minimal expansile invasion into the ductal wall and four were noninvasive. Five patients were treated with a Whipple operation, three underwent segmental resections, and one underwent a left hepatic lobectomy. One patient died of unrelated causes 16 years after a Whipple operation, and another died of postoperative complications. The remaining 7 patients are alive and disease free 1-13 years after surgery.

CONCLUSIONS

Noninvasive and minimally invasive papillary carcinomas of the EBD are associated with excellent long term prognosis regardless of their cytologic features or their immunohistochemical reactivity to p53 and MIB-1. These tumors should be distinguished from biliary papillomatosis, intraductal papillary mucinous carcinomas of the pancreas extending into the bile ducts, papillary adenomas, and papillary hyperplasia.

Noninvasive and minimally invasive papillary carcinomas of the extrahepatic bile ducts

BACKGROUND

Adenocarcinomas of the extrahepatic bile ducts (EBD) are uncommon neoplasms that are morphologically heterogenous and associated with a poor prognosis. Papillary carcinomas of the EBD, however, appear to follow a much less aggressive clinical course.

METHODS

The authors reviewed the clinical records of nine patients with papillary carcinoma of the EBD, analyzed the microscopic features, and selected immunohistochemical reactivity (p53 and MIB-1) that might correlate with patient survival.

RESULTS

Six patients were male and three were female, with a mean age of 65 years (range, 48-83 years). The clinical presentation of disease in these patients was similar to that reported for conventional adenocarcinoma of EBD. According to their cell phenotypes, these papillary carcinomas were classified as biliary type (7 cases) and intestinal type (2 cases). Most were located in the common bile duct and were well differentiated (7 cases). Five showed minimal expansile invasion into the ductal wall and four were noninvasive. Five patients were treated with a Whipple operation, three underwent segmental resections, and one underwent a left hepatic lobectomy. One patient died of unrelated causes 16 years after a Whipple operation, and another died of postoperative complications. The remaining 7 patients are alive and disease free 1-13 years after surgery.

CONCLUSIONS

Noninvasive and minimally invasive papillary carcinomas of the EBD are associated with excellent long term prognosis regardless of their cytologic features or their immunohistochemical reactivity to p53 and MIB-1. These tumors should be distinguished from biliary papillomatosis, intraductal papillary mucinous carcinomas of the pancreas extending into the bile ducts, papillary adenomas, and papillary hyperplasia.

Noninvasive and minimally invasive papillary carcinomas of the extrahepatic bile ducts

BACKGROUND

Adenocarcinomas of the extrahepatic bile ducts (EBD) are uncommon neoplasms that are morphologically heterogenous and associated with a poor prognosis. Papillary carcinomas of the EBD, however, appear to follow a much less aggressive clinical course.

METHODS

The authors reviewed the clinical records of nine patients with papillary carcinoma of the EBD, analyzed the microscopic features, and selected immunohistochemical reactivity (p53 and MIB-1) that might correlate with patient survival.

RESULTS

Six patients were male and three were female, with a mean age of 65 years (range, 48-83 years). The clinical presentation of disease in these patients was similar to that reported for conventional adenocarcinoma of EBD. According to their cell phenotypes, these papillary carcinomas were classified as biliary type (7 cases) and intestinal type (2 cases). Most were located in the common bile duct and were well differentiated (7 cases). Five showed minimal expansile invasion into the ductal wall and four were noninvasive. Five patients were treated with a Whipple operation, three underwent segmental resections, and one underwent a left hepatic lobectomy. One patient died of unrelated causes 16 years after a Whipple operation, and another died of postoperative complications. The remaining 7 patients are alive and disease free 1-13 years after surgery.

CONCLUSIONS

Noninvasive and minimally invasive papillary carcinomas of the EBD are associated with excellent long term prognosis regardless of their cytologic features or their immunohistochemical reactivity to p53 and MIB-1. These tumors should be distinguished from biliary papillomatosis, intraductal papillary mucinous carcinomas of the pancreas extending into the bile ducts, papillary adenomas, and papillary hyperplasia.

Inherited medullary microcarcinoma of the thyroid: a study of 11 cases

The authors report 11 patients with genetically determined medullary microcarcinomas. Nine patients were either children or adolescents and two patients were young adults. The youngest patient was 7 years old and the oldest was 34 years of age (mean age, 15.4 yrs). The preoperative diagnosis was based on family history and elevated serum calcitonin levels. In addition, six patients had RET protooncogene mutations in exons 10, 11, and 16. Two patients who had the RET protooncogene mutations did not have serum calcitonin measurements. Nine patients had bilateral medullary microcarcinomas (<1.0 cm), whereas the two patients with unilateral tumors demonstrated multifocal disease. The principle microscopic differences between these genetically determined medullary microcarcinomas and larger sporadic (>1 cm) medullary carcinomas were the low incidence of stromal desmoplasia and amyloid deposition, the high incidence of C-cell hyperplasia, and the low incidence of lymph node metastases. Only one patient, a 34-year-old man, presented with lymph node metastases. All patients remain disease free 11 to 70 months after diagnosis. This small series of thyroid microcarcinomas illustrates the impact molecular diagnostics is having on the management and prognosis of genetically determined medullary carcinoma.

Genetic abnormalities involved in the pathogenesis of gallbladder carcinoma

While considerable progress has been made in the understanding of the genetic changes involved in the pathogenesis of several human neoplasms, there is limited information about the genetic changes involved in the development of gallbladder carcinoma. Several studies indicate that TP53 (17p13) and p16(Ink4)/CDKN2 (9p21-22) gene loci abnormalities are frequent and early events in the pathogenesis of this neoplasm, in some cases preceding the onset of histological changes of invasion. Preliminary data also suggest that deletions at other chromosomal regions (8p21 and DCC at 18q21 loci) may play an important role in the development of gallbladder carcinoma; however, they need to be further analyzed. K-ras gene mutations appear to be an infrequent event in this neoplasm, except in gallbladder carcinomas associated with congenital abnormalities of the biliary tract. Genetic studies confirm that the sequence dysplasia-carcinoma in situ (CIS) is the usual route for the development of gallbladder carcinoma, and our recent data strongly suggest that adenomas are not precursors of this neoplasm.

Endometrial endometrioid carcinomas associated with Ewing sarcoma/peripheral primitive neuroectodermal tumor

Three uterine tumors, each consisting of endometrioid carcinoma and Ewing's sarcoma/peripheral primitive neuroectodermal tumor (ES/pPNET) are described. The diagnosis of ES/pPNET in each case was first established in the hysterectomy specimen because each ES/pPNET was misinterpreted on the endometrial biopsy specimens as a high-grade homologous sarcoma. The ES/pPNET element in each case consisted of solid masses of small- to medium-sized round cells without Homer-Wright pseudorosettes, glial or ganglion cells, true rosettes with central lumens, or medulloepithelial tubules. Each ES/pPNET exhibited focal positive immunostaining for neuron-specific enolase, diffuse staining for vimentin, and strong cell membrane immunoreactivity for O13 (CD99), the last finding providing the first clue to the diagnosis of ES/pPNET in each case. The diagnosis in each case was confirmed by detection of EWS/FLI-1 fusion transcript through reverse transcription polymerase chain reaction. We also examined O13 immunoreactivity retrospectively in 40 cases of malignant mixed mullerian tumors (MMMT) with homologous or heterologous elements. O13 immunoreactivity was not observed in the malignant epithelium or in the homologous or heterologous sarcomas. The immunoreactivity of O13 in round cell endometrial sarcomas provides a clue to the diagnosis of ES/pPNET.

Uterine metastasis from a heterologous metaplastic breast carcinoma simulating a primary uterine malignancy

OBJECTIVE

To describe the first distant metastasis of a heterologous metaplastic breast carcinoma in the uterus and discuss its differential diagnosis.

METHODS

Light microscopy, immunohistochemistry, and flow cytometry were used to evaluate the tumor.

RESULTS

A 58-year-old woman underwent mastectomy for metaplastic breast carcinoma confined to the breast. She presented 4 years later with vaginal bleeding. The endometrial curettage showed a poorly differentiated carcinoma. She underwent hysterectomy and bilateral salpingo-oophorectomy as well as pelvic and periaortic lymphadenectomy. Clinical and intraoperative findings favored a primary uterine malignancy. The uterus was markedly distorted with multiple gray-white, solid subserosal, and intramural tumor nodules. The tumor diffusely infiltrated the endometrium sparing benign endometrial glands. The tumor nodules were distributed full thickness of the myometrium. These nodules were composed of high-grade malignant epithelial cells with areas of chondroid metaplasia. Extrauterine microscopic tumor was present in left ovary, pelvic, and periaortic lymph nodes. The histologic features and estrogen/progesterone receptors (ER/PR) as well as DNA ploidy analysis of the uterine tumor showed striking similarity with those of the primary metaplastic breast carcinoma. A diagnosis of metastatic metaplastic breast carcinoma in the uterus was rendered.

CONCLUSION

A metastatic heterologous metaplastic breast carcinoma with cartilaginous metaplasia should be considered in the differential diagnosis of heterologous uterine malignant mixed mesodermal tumor (MMMT) and high-grade endometrioid carcinoma with rare foci of cartilage.

Mucinous cystic neoplasms of the pancreas

Since their initial description, mucinous cystic neoplasms have been difficult to classify. This article attempts to clarify histological, clinical, and genetic criteria so that the pathologist can categorize each mucinous cystic neoplasm into 1 of 4 possible categories. Mucinous cystadenomas contain a single layer of mucin-producing, columnar epithelium lacking significant atypia. Borderline mucinous cystic neoplasms contain cells with moderate atypia. Mucinous cystic neoplasms with in situ carcinoma show significant architectural and cytological atypia. When invasive carcinoma is present in association with a mucinous cystic neoplasm, then the diagnosis of invasive mucinous cystadenocarcinoma should be made. The categorization of mucinous cystic neoplasms into these groups is essential because it accurately predicts outcome, provided that the tumor has been sampled and examined thoroughly. Completely removed mucinous cystadenomas, borderline mucinous cystic neoplasms, and mucinous cystic neoplasms with in situ carcinoma follow benign courses. Partial resection should be avoided as evidence suggests that mucinous cystic neoplasms can progress from adenomas to borderline lesions to carcinomas in situ to invasive carcinomas over time; partial resection should be avoided if possible. Modern molecular genetic techniques are helping to unravel the origins of rare variants of mucinous cystic tumors, such as the mucinous cystic tumor with an associated osteoclast-like giant cell tumor and the mucinous cystic tumor with sarcomatous stroma.

Pancreatic mucinous cystic neoplasms with sarcomatous stroma: molecular evidence for monoclonal origin with subsequent divergence of the epithelial and sarcomatous components

Neoplasms with mixed carcinomatous and sarcomatous growth patterns occur in many organs and tissues. The pathogenesis of these cancers is thought to be either the result of two independent neoplastic processes merging to form a single tumor, or a neoplasm of monoclonal origin that develops phenotypic diversity. To address this issue, we characterized molecular alterations in separately microdissected epithelial and sarcomatous areas in three cases of pancreatic mucinous cystic neoplasms with sarcomatous stroma. Using microsatellite markers for six chromosomal loci commonly deleted in infiltrating ductal adenocarcinomas of the pancreas, we found genetic alterations to be virtually identical between the sarcomatous and epithelial components of two of the three neoplasms. In the third neoplasm, we found allelic losses and retentions to be identical at five of the six chromosomal loci, but at a single locus, we noted allelic loss in the neoplastic epithelial component but not the sarcomatous component. The same neoplasms were also analyzed for activating point mutations in codon 12 of the K-ras gene by using mutant-enriched polymerase chain reaction and allele-specific oligonucleotide hybridization. A K-ras mutation was identified in the epithelial component of one of the three neoplasms (the same tumor with an additional allelic loss in the neoplastic epithelial cells), but the sarcomatous component of this tumor was wild-type at codon 12 of K-ras, as were both components of the other two neoplasms. Overall, these results suggest a monoclonal origin with subsequent divergence of the neoplastic epithelial and sarcomatous portions of these neoplasms.

Protocol for the examination of specimens from patients with carcinomas of the gallbladder, including those showing focal endocrine differentiation: a basis for checklists. Cancer Committee of the College of American Pathologists

No Abstract Available

Protocol for the examination of specimens from patients with carcinomas of the extrahepatic bile ducts, exclusive of sarcomas and carcinoid tumors: a basis for checklists. Cancer Committee of the College of American Pathologists

No Abstract Available

Pyloric gland metaplasia with perineural invasion of the gallbladder: A lesion that can be confused with adenocarcinoma

BACKGROUND

Metaplastic pyloric glands have been described in a variety of organs including the gallbladder, in which they can extend into the muscular wall and serosa.

METHODS

Clinical, histologic, and immunohistochemical features of four cases of gallbladder florid pyloric gland metaplasia with perineural and intraneural invasion are analyzed.

RESULTS

The patients with pyloric gland metaplasia and perineural and intraneural invasion were all females ages 57-72 years. A preoperative diagnosis of chronic cholecystitis and cholelithiasis was made for all four patients, but a histologic diagnosis of adenocarcinoma was made for two patients and entertained in two others. Macroscopically the gallbladders showed changes usually associated with chronic cholecystitis. No intraluminal masses were observed in any of the gallbladders. The characteristic microscopic features included florid pyloric gland metaplasia, proliferation of medium-sized nerve trunks more prominent in the muscular layer and serosa, and perineural and intraneural invasion by the metaplastic glands lined by cytologically bland cuboidal or columnar mucin-containing cells. At last follow-up all patients were alive and symptom free 1-7 years after laparoscopic cholecystectomy.

CONCLUSIONS

Pyloric gland metaplasia of the gallbladder should be added to the long and increasing list of benign epithelial proliferations that are associated with perineural and intraneural invasion. This lesion should not be mistaken for adenocarcinoma of the gallbladder, a misinterpretation that may have serious therapeutic implications. The pathogenesis of this phenomenon is unknown.

Molecular abnormalities associated with secretory carcinomas of the breast

Secretory carcinomas (SCAs) represent a unique histological variant of invasive breast carcinomas, occurring predominantly in patients younger than 30 years of age. Data from limited series have shown SCAs to have a favorable prognosis in patients younger than 20 years of age, whereas the clinical course tends to parallel the more common in filtrating ductal carcinomas (IDCs) in patients older than 20 years. There are no reports on the molecular abnormalities associated with this unusual tumor. Microdissected archival formalin-fixed tissue from 10 SCAs collected from 2 institutions were used to determine the frequencies of allelic loss at 13 chromosomal regions with 19 microsatellite markers, using multiplex polymerase chain reaction (PCR)-based techniques. The results of loss of heterozygosity (LOH) and microsatellite alterations (MAs) analyses were compared with 20 cases of IDCs. P53 gene mutation analysis was also performed on the 10 SCAs using single-strand conformation polymorphism (SSCP) analysis, followed by sequencing of abnormal bands. LOH at multiple regions of chromosome 3p were the most common abnormality in both SCAs (55%) and IDCs (50%), followed by LOH at 17q21 (BRCA1 locus), 13q14 (retinoblastoma gene locus), and 8p21-23. No significant differences were seen in the frequencies of LOH at any chromosomal region except for 17p13 (p53 gene locus), where allelic losses were absent in SCAs, but evident in 46% of IDCs (P < .05). The 2 histological entities were similar in the fractional regional loss (FRL) index (0.26 v 0.24), fractional allelic loss (FAL) index (0.23 v 0.27), as well as in the frequency of MAs (0.015 v 0.005), P > .05. P53 gene missense mutation (G:C::A:T) was detected in 1 of 10(10%) SCAs. Based on the considerable similarities in the molecular abnormalities associated with both tumors, the formation of secondary lumina in both the in situ and the invasive components, as well as suggestions from limited series that the clinical behavior in adult patients parallels that of IDCs, SCA most likely reflects a secretory variant of IDCs.

Correlation of CD44S expression in renal clear cell carcinomas with subsequent tumor progression or recurrence

BACKGROUND

Recent reports have shown altered expression of CD44 in renal cell carcinomas. However, to the authors' knowledge there are no data correlating CD44 expression in renal cell carcinomas with subsequent tumor progression or recurrence, nor is there information about the presence of particular splice variants of CD44 in these tumors.

METHODS

The authors examined the immunohistochemical expression of CD44S, the standard isoform of CD44, in renal cell carcinomas from 43 patients using 2 different monoclonal antibodies, Mab2137 and Hermes-3. In addition, they stained the renal cell carcinomas with antibodies to 2 splice variants of CD44, CD44v3 and CD44v6.

RESULTS

Increased staining of renal clear cell carcinomas with Mab2137 was observed in high grade versus low grade tumors (45% vs. 0%, P = 0.013), whereas increased staining of clear cell carcinomas with Hermes-3 was noted in high stage versus low stage tumors (40% vs. 0%, P = 0.006). Few tumors stained with antibodies to CD44v3. Although increased expression of the splice variant CD44v6 was noted in papillary versus clear cell carcinomas, and increased staining of papillary carcinomas with Mab2137 and with antibodies to CD44v6 was noted for low stage versus high stage tumors, these differences did not achieve statistical significance. Clinical follow-up of at least 43 months was available for 26 patients. Six of these patients (five with clear cell carcinoma and one with papillary carcinoma) developed progressive or recurrent disease. The primary tumors from all 5 patients with progressive or recurrent clear cell carcinoma showed staining with Mab2137, whereas the primary tumors from only 2 of the 15 patients with at least 43 months follow-up and no evidence of progressive or recurrent clear cell carcinoma (13%) showed staining with Mab2137 (P = 0.001). Alternatively, 5 of 7 clear cell carcinomas (71%) that stained with Mab2137 were from patients who subsequently developed recurrence or progression, compared with 0 of 13 clear cell carcinomas that did not stain. Similar findings were not observed for papillary carcinomas, which appeared to be biologically distinct from clear cell carcinomas.

CONCLUSIONS

CD44S staining with Mab2137 correlates with progression or recurrence of clear cell renal cell carcinoma. CD44S may, therefore, play a pathogenetic role in tumor progression.

Expression of the RNA component of human telomerase in adult testicular germ cell neoplasia

BACKGROUND

During human development, telomerase is repressed in most somatic cells, whereas it is maintained in male germline cells. Reactivation of telomerase has been associated with somatic cancers. To the authors' knowledge, the role of telomerase in germ cell derived malignancies has not previously been evaluated.

METHODS

A radioactive in situ hybridization method was used to study the expression of the RNA component of human telomerase (hTR) in 22 cases of adult testicular germ cell neoplasia encompassing all major histomorphologic types. For precise cell identification, hTR in situ hybridization was combined with immunohistochemistry in select cases.

RESULTS

Testicular germ cell tumors showed differential expression of hTR. The highest level of expression was seen in embryonal carcinoma. Seminoma and unclassified intratubular germ cell neoplasia exhibited moderate levels of expression. Yolk sac tumor was characterized by a range of expression, which mirrored its morphologic variation. Immature teratoma recapitulated the down-regulation of telomerase manifested during human embryogenesis. Mature teratoma represented the adult pattern of somatic repression. Notably, choriocarcinoma showed modest expression. The expression of spermatocytic seminoma was intermediate between that of classic seminoma and embryonal carcinoma. No difference in expression was evident between matching intratubular and invasive components. In nonneoplastic testis, hTR expression was down-regulated during spermatogenesis and was absent in spermatozoa. Expression was negligible in rete testis and interstitial Leydig cells, and low in epididymis. Unexpectedly, Sertoli cells, which are testicular accessory somatic cells, displayed the most intense expression observed in this study.

CONCLUSIONS

In testicular germ cell tumors of young adults (and during spermatogenesis), hTR expression is down-regulated with differentiation, irrespective of the aggressiveness of the tumors. Spermatocytic seminoma, regarded as a low grade malignancy, shows moderately intense expression.

Pathologic examination accurately predicts prognosis in mucinous cystic neoplasms of the pancreas

The behavior of pancreatic mucinous cystic neoplasms has long been debated. Some authors contend that histologically benign neoplasms can recur and metastasize. We reviewed the gross and microscopic findings and outcomes of 61 mucinous cystic neoplasms diagnosed at The Johns Hopkins Hospital from March 20, 1984 to July 8, 1998. Each neoplasm was placed into one of four categories based on complete histologic examination: invasive mucinous cystadenocarcinoma, mucinous cystic neoplasm with in situ carcinoma, borderline mucinous cystic neoplasm, and mucinous cystadenoma. Neoplasms in the latter three categories were included only if they were entirely resected and completely examined. Patient outcomes were obtained from hospital records and patient and physician follow-up. Twenty (33%) of the patients had invasive mucinous cystadenocarcinomas, and they had 2- and 5-year disease-specific survival rates of 67% and 33% (mean follow-up of survivors, 4.2 years), respectively. Nine (15%) patients had mucinous cystic neoplasms with in situ carcinoma (mean follow-up of survivors, 4.1 years). Five (8.2%) patients had borderline mucinous cystic neoplasms (mean follow-up of survivors, 5.6 years). Twenty-seven (44%) patients had mucinous cystadenomas (mean follow-up of survivors, 5.1 years). No mucinous cystadenoma, borderline mucinous cystic neoplasm, or mucinous cystic neoplasm with in situ carcinoma recurred or metastasized. No patient with the diagnosis of mucinous cystadenoma, borderline mucinous cystic neoplasm, or mucinous cystic neoplasm with in situ carcinoma died of disease. The difference in disease-specific survival rates between patients with invasive mucinous cystadenocarcinomas and those with noninvasive tumors was significant (p < 0.0001, log-rank test). One case, originally showing only benign histology on incisional biopsy, contained foci of invasive carcinoma on complete resection. Completely resected and entirely examined mucinous cystadenomas, borderline mucinous cystic neoplasms, and mucinous cystic neoplasms with in situ carcinoma follow benign courses. Because invasive carcinoma can be focal, failure to study an entire mucinous cystic neoplasm may result in the miscategorization of a malignant neoplasm as benign.

Frequent expression of beta-human chorionic gonadotropin (beta-hCG) in squamous cell carcinoma of the cervix

Human chorionic gonadotropin (beta-hCG) has been detected within tissue homogenates, culture fluid, and sera of patients with squamous cell carcinoma of the cervix. Studies regarding in vivo localization of beta-hCG in squamous cell carcinoma of the cervix are scant and conflicting. Cervical samplings (biopsy and/or curettage specimens) of 63 cases of poorly differentiated invasive squamous cell carcinoma of the cervix were initially stained by the immunoperoxidase technique for the presence of beta-hCG and human placental lactogen (hPL). Based on beta-hCG reactivity, patients were divided into beta-hCG-positive and beta-hCG-negative groups. Thirty-three of the 63 (52%) cases showed localization of beta-hCG in tumor cells. Subsequent specimens of patients, who underwent surgical treatment, were likewise examined for beta-hCG reactivity. These surgical specimens showed focal beta-hCG reactivity in the beta-hCG-positive group only. The beta-hCG reactivity was seen in both high-grade SIL (CIN III), invasive squamous cell carcinoma, and its metastases. The focal beta-hCG reactivity was predominantly confined to the peripheral tumor cells at the stromal-epithelial interface in noninvasive and invasive lesions. Intensity of immunostaining was moderate to strong. The beta-hCG staining was observed in different cancer stages and in various age groups. No hPL reactivity was seen in any cases. Poorly differentiated squamous cell carcinoma of uterine cervix showing immunoreactivity for beta-hCG should be distinguished from choriocarcinoma and other trophoblastic tumors.

Allelic losses at chromosome 3p are seen in human papilloma virus 16 associated transitional cell carcinoma of the cervix

OBJECTIVE

Transitional cell carcinomas (TCCs) of the cervix are rare neoplasms of the female genital tract. Although these tumors display urothelial differentiation, there is controversy regarding their histogenetic relationship to squamous cell carcinomas (SCC) of the cervix versus transitional cell carcinomas of the bladder.

METHODS

We performed partial allelotyping of five TCCs of the cervix using 23 polymorphic markers located on chromosomes 3p and 9, which demonstrate frequent and early losses in cervical SCC and urothelial TCC, respectively. Multiplex polymerase chain reaction was used on DNA extracted from archival paraffin-embedded tissue using precise microdissection. Additionally, P53 gene mutation analysis was performed using single-strand confirmation polymorphism (SSCP) and the presence of human papilloma virus (HPV) sequences was analyzed using general and specific (types 16 and 18) primers.

RESULTS

General HPV sequences were demonstrated in all cases, but the oncogenic strain HPV 16 was present in only three (60%) of the five tumors; no HPV 18 was detected in any sample. Three of five TCCs, all harboring HPV 16 sequences, demonstrated concurrent allelic losses at several 3p loci (specifically 3p12, 3p14.2 [the FHIT gene locus], 3p21.3, and 3p22-24.2). LOH at a single locus on 9q32-qter was demonstrated in one tumor; no other deletions were seen on chromosome 9. P53 gene mutations in exons 5-8 were absent by SSCP analysis.

CONCLUSIONS

The infrequent involvement of chromosome 9 in TCCs of the cervix, along with the concurrent presence of 3p LOH and oncogenic HPV 16 in a subset of tumors, suggests a closer histogenetic relationship of this neoplasm to cervical SCCs rather than urothelial TCCs.

Signet-ring cell variant of small lymphocytic lymphoma with a prominent sinusoidal pattern

Signet-ring cell lymphoma is a rare morphologic variant of non-Hodgkin's lymphoma characterized by neoplastic lymphoid cells with cytoplasmic vacuoles or eosinophilic globules that impart a signet-ring cell morphology. Although most cases are variants of follicular center B-cell lymphomas, this pattern also can be seen in T-cell lymphomas. An indolent clinical course and prolonged survival have characterized the majority of published cases. We document the case of a 62-year-old African-American woman with diffuse small lymphocytic signet-ring lymphoma having a predominant sinusoidal growth pattern, which, to our knowledge, has not been previously reported. The prominent sinusoidal pattern of signet-ring lymphocytes contributes to its confusion with metastatic signet-ring cell adenocarcinoma. The correct diagnosis is greatly facilitated by the use of appropriate immunohistochemical stains for lymphoid markers.

K-ras and p53 mutations in the pathogenesis of classical and goblet cell carcinoids of the appendix

BACKGROUND

Mutations in the K-ras oncogene and the p53 tumor suppressor gene are present in approximately 50% of colonic adenocarcinomas. Goblet cell carcinoids (GCCs) are uncommon neoplasms of the appendix that appear to be intermediate between carcinoid tumors and adenocarcinomas, both histologically and biologically. The current study was undertaken to examine the role of p53 and K-ras mutations in the pathogenesis of GCCs and typical carcinoids (TCs) of the appendix.

METHODS

Archival materials from 22 GCCs and 18 TCs were analyzed. K-ras mutations in codons 12, 13, and 61 were studied by a polymerase chain reaction (PCR) based designed restriction fragment length polymorphism method using mismatched nested primers. Mutations in exons 5-8 of the p53 tumor suppressor gene were analyzed in 16 GCCs and 18 TCs by PCR and single-strand conformational polymorphism followed by direct sequencing. Immunostains for p53 and chromogranin were performed in all cases.

RESULTS

K-ras mutations and nuclear accumulation of p53 by immunohistochemistry were not detected in any of the GCCs or TCs. p53 mutations were found in 4 of 16 GCCs (25%) and 8 of 18 TCs (44%). Immunoreactivity for chromogranin was seen in the vast majority of GCCs and TCs.

CONCLUSIONS

p53 mutations appear to play a role in the pathogenesis of some GCCs and in approximately 50% of TCs of the appendix, whereas mutations in the K-ras oncogene do not appear to be important in the development of these tumors. The minimal cytologic atypia, low incidence of metastases, and lack of K-ras mutations in goblet cell appendiceal neoplasms suggest that they are variants of carcinoid tumors. Our findings lend support to the recommendation that the therapeutic guidelines applied to TCs of the appendix should be the same for GCCs.

Intrasellar adenoid cystic carcinoma and papillary mucinous adenocarcinoma: two previously undescribed primary neoplasms at this site

Most carcinomas involving the sella turcica are metastases. We report two previously undescribed carcinomas that appear to be primary at this site. The first occurred in a 44-year-old woman who presented with hemianopsia. A mass was noted by computed tomography to occupy the sella turcica, from which it appeared to originate. Transphenoidal biopsy showed the tumor to be an adenoid cystic carcinoma with a typical cribriform pattern. The patient died shortly after a subsequent attempt at tumor resection. The second tumor arose in a 55-year-old man who presented with diplopia. Computed tomography showed a mass in the sella turcica that was presumed to be a pituitary adenoma. However, transphenoidal resection revealed a mucinous adenocarcinoma composed of small papillae and glands lined by columnar epithelium. The tumor cells exhibited varying degrees of stratification with prominent interspersed mucin vacuoles. Focal solid areas showed a component of signet ring-type cells. In contrast to the apparent aggressive behavior of the adenoid cystic carcinoma, the papillary mucinous adenocarcinoma appeared much less aggressive, as the second patient was alive and without evidence of disease 5 years later. Both tumors may be derived from epithelial rests within the pituitary gland, either minor salivary gland rests or Rathke's cleft remnants.

Loss of heterozygosity at 3p in benign lesions preceding invasive breast cancer

BACKGROUND

Loss of heterozygosity (LOH) at chromosome 3p is one of the most common genetic abnormalities identified in human cancers and has occasionally been noted in benign proliferative lesions predisposing to breast cancer. If the frequency of LOH at 3p in benign proliferative lesions correlates with the subsequent development of breast cancer, it may be possible to develop powerful tools for molecular risk assessment based on this technology.

MATERIALS AND METHODS

Archival paraffin-embedded tissues from benign breast biopsies in five women who have developed breast cancer and three women who have not developed breast cancer were microdissected and allelotyped at 3p using six microsatellite markers.

RESULTS

No LOH was detected in the biopsies from women who have not developed breast cancer. For women developing breast cancer, the proportion of informative loci showing LOH in the benign proliferative lesions was 0.47 as compared to 0.57 for the associated breast cancers. There was no LOH detected in epithelial DNA from a fibroadenoma. Of 15 informative loci, 4 (27%) showed LOH in both the benign proliferative lesion and the associated cancer; however, the actual parental allele lost was different in three of these four cases.

CONCLUSIONS

These results suggest that there are specific patterns of genetic instability common to preneoplastic lesions and the breast cancers that subsequently develop even when the paired lesions are not clonally related. LOH analysis of benign breast epithelium may provide a tool for molecular risk assessment and a surrogate endpoint for breast cancer chemoprevention trials.

Low grade fibromyxoid sarcoma: fine-needle aspiration cytology with histologic, cytogenetic, immunohistochemical, and ultrastructural correlation

BACKGROUND

Although the histologic features of the recently described low grade fibromyxoid sarcoma are well established, to the authors' knowledge there are no reports in the literature describing the cytologic features of this tumor by fine-needle aspiration. Recognition of this lesion is important because of its indolent but metastasizing nature.

METHODS

The authors retrospectively reviewed their surgical pathology files for cases of low grade fibromyxoid sarcoma with a preoperative fine-needle aspiration biopsy (FNAB); three such cases were found. Immunohistochemical studies were performed in all three tumors, ultrastructural examination was performed in two tumors, and fresh tissue for cytogenetic analysis was obtained in one tumor.

RESULTS

All FNABs showed similar features. The aspirates were relatively hypocellular with an abundant myxoid background; the neoplastic cells contained oval to spindle shaped nuclei with minimal pleomorphism. No capillaries or areas of fibrous tissue were identified. Cytogenetic study of one case revealed no chromosomal abnormalities. The histologic findings were characteristic for this lesion. By immunohistochemistry the tumor cells showed diffuse and strong reactivity for vimentin only; at the ultrastructural level the neoplastic spindle cells had characteristics of fibroblasts.

CONCLUSIONS

The cytologic features of low grade fibromyxoid sarcoma are not specific enough for a definitive diagnosis based on FNAB alone; however, correlating the cytologic and clinical findings can narrow the range of diagnosis. The differential diagnosis includes other myxoid lesions, in particular superficial or intramuscular myxoma and myxofibrosarcoma. In addition, the immunohistochemical and ultrastructural findings support a fibroblastic origin for this neoplasm.