Several recent studies have suggested that testicular germ cell tumors express high levels of wild-type p53 protein. To clarify and confirm this unexpected result, we have investigated seminomatous and nonseminomatous germ cell tumors at the genomic, mRNA, and protein levels. Thirty-five tumors were examined for p53 overexpression using antibodies directed against the p53 (PAb1801, PAb240, and CM1), mdm2 (IF2), and p21Waf1/Clp1 (EA10) proteins. Thirty-two tumors were screened for p53 mutations by single-strand conformation polymorphism analysis. Eighteen tumors were screened with a functional assay that tests the transcriptional competence of human p53 protein expressed in yeast. On frozen sections, 100, 65, 35, 73, and 0% of tumors reacted with the CM1, PAb240, PAb1801, IF2, and EA10 antibodies, respectively. No p53 mutations were detected by single-strand conformation polymorphism or by functional assay. The fact that many tumors overexpress wild-type p53 but not mdm2 rules out mdm2 overexpression as a general explanation for the presence of wild-type p53 in these tumors. The absence of p21 overexpression suggests that p53 may be unable to activate transcription of critical target genes, which may explain why the presence of wild-type p53 is tolerated in this tumor type, although the mechanism for this transcriptional inactivity remains to be established.

Neuropeptide Y (NPY) is a 36 amino acid peptide known to inhibit glucose-stimulated insulin secretion. NPY has been shown to be synthesized and secreted by rat islets of Langerhans. More recently, we described the presence of NPY within human islets of Langerhans and in several pancreatic endocrine tumors. In this report, we describe the case of a patient presenting with an insulinoma who underwent the surgical resection of the tumor and was studied in vivo and in vitro for NPY production. Using a highly specific and sensitive two-site amplified enzyme-linked immunosorbent assay, we detected high plasma NPY levels in the patient prior to the surgical resection of the tumor which returned to normal after surgery. NPY was secreted from the tumor when kept in primary cell culture. Furthermore, immunohistochemistry of the insulinoma revealed the presence of NPY and its C-flanking peptide together with insulin, chromogranin and neuron specific enolase. It is concluded that elevated circulating NPY levels observed in this patient with an insulinoma reflected in vivo secretion by the tumor and it is hypothesized that NPY could potentially be used as an endocrine marker in patients with suspected insulinoma.

Male infiltrating breast carcinomas are rare and seem to have different characteristics, prognosis and sensitivity to hormonal treatment than those of female breast carcinomas. Our aim was to determine whether markers which have an established rôle in women are also important in men. 66 male infiltrating-ductal breast carcinomas were compared with 190 female breast carcinomas of the same type. Various markers were studied using immunohistochemistry. Tumour size at diagnosis, grade, number of axillary metastases and prognosis were comparable in male and female breast carcinomas. However, male breast carcinomas were characterised by a higher percentage of oestrogen receptor (OR) reactivity, and weekly associated with markers that, in women, are under oestrogen control. Male breast carcinomas were positive for markers under androgen control. Male breast carcinomas also differed from female carcinomas by the low percentage of p53+ and the high percentage of bcl-2+ tumours. The phenotype of male breast carcinomas has characteristics that could have repercussions on prognosis and on the choice of hormonal treatment. Only a few male breast cancers are p53+. OR, which are frequently present in male tumours, are probably not functional. In contrast, androgen receptors seem efficient, as several markers under androgen control are expressed. Therefore, the selection of hormonal therapy should not be based on OR status only.

Neuropeptide Y (NPY) is a 36 amino acid peptide known to inhibit glucose-stimulated insulin secretion. NPY has recently been shown to be synthetized within rat islets of Langerhans and to be secreted in a differentiated rat insulin-secreting cell line, and as to this date the localization of NPY in human endocrine pancreas has not been reported. As NPY shares high amino acid sequence homology with peptide YY (PYY) and pancreatic polypeptide (PP), the polyclonal antibodies reised against these peptides often cross-react with each other. To demonstrate the presence of NPY in the human endocrine pancreas, we used a highly specific monoclonal antibody raised against NPY and another against its C-flanking peptide (CPON). We studied three cases of hyperplasia of Langerhans islets and 11 cases of endocrine tumors of the pancreas. NPY and CPON were detected in all three cases of hyperplasia. For the 11 pancreatic tumors, five and nine of the tumors were positive for the antibodies NPY and CPON, respectively. The two negative tumors for CPON immunoreactivity were differentiated insulinomas, which showed no evidence of other hormonal secretion. In normal human Langerhans islet, NPY and CPON immunoreactivities were colocalized in glucagon-producing cells (α-cells) and in a few insulin-secreting cell (β-cells). In conclusion, 1) NPY-specific immunoreactivity was found to be present in human Langerhans islets and some tumors of the endocrine pancreas, 2) in normal human Langerhans islet, NPY is predominantly present in α-cells and in a few β-cells, 3) NPY may be used as a marker of the endocrine pancreas, and 4) the functional role of NPY within human islets of Langerhans and plasma NPY levels in patients diagnosed with endocrine pancreatic tumors remains to be established.

One hundred and eighty-eight infiltrating ductal carcinomas of the breast were examined immunohistochemically (IMM) for p53, and the results were compared to those of single strand conformation polymorphism (SSCP). Of the 65 IMM+ cases (35%), 32 showed a genetic alteration in exons 5 to 9. In some of the IMM+ SSCP- cases, the number of 53+ cells in the tumor was too low to be detected by SSCP. Cases with only a few p53+ cells must not necessarily be considered negative, because a genetic alteration has been found in nine such cases. However, in a few cases, the accumulation of p53 protein could be caused by a factor other than mutation. Of the 123 IMM- cases, six showed gene polymorphism. p53 phenotype, as established with three monoclonal antibodies, did not correlate with genetic alteration in a particular exon. p53 IMM+ or SSCP+ tumors were generally ER-, grade III tumors and were uncommon in women older than 69 yr of age. The two methods have almost the same prognostic value. The accumulation of p53 protein is a good indicator of p53 mutation and therefore, immunohistochemistry remains a good method for the detection of such mutations.

Eight ovarian carcinoids, 4 trabecular and 4 strumal have been studied immunohistochemically for polypeptide hormones; three of them were also examined with the electron microscope. Seven of eight cases were positive for at least one polypeptide hormone. The trabecular parts of the 4 cases of strumal carcinoid were positive for pancreatic polipeptide. As the vesicular regions of these 4 cases were positive for thyroglobulin and for pancreatic polipeptide, we suspect the existence of <<hybrid>> thyroid and neuroendocrine cells. The electron microscopic examination revealed: the cell in the insular carcinoid had no distinct polarization and contained electrondense granules of varying shape; in the trabecular part of the strumal carcinoid the cells were polarized and contained round electron- dense granules.

Eight ovarian carcinoids, 4 trabecular and 4 strumal have been studied immunohistochemically for polypeptide hormones; three of them were also examined with the electron microscope. Seven of eight cases were positive for at least one polypeptide hormone. The trabecular parts of the 4 cases of strumal carcinoid were positive for pancreatic polypeptide. As the vesicular regions of these 4 cases were positive for thyroglobulin and for pancreatic polypeptide, we suspect the existence of "hybrid" thyroid and neuroendocrine cells. The electron microscopic examination revealed: the cell in the insular carcinoid had no distinct polarization and contained electron-dense granules of varying shape; in the trabecular part of the strumal carcinoid the cells were polarized and contained round electron-dense granules.

A group of 196 ductal infiltrating carcinomas of the breast was examined immunohistochemically for p53. The purpose of this study was to show whether frozen and fixed tissues are equally adequate for detection of p53 and which antibodies should be used to have a prognostic value. Detection was superior on frozen to that on formalin-fixed tissues. It was not possible with any method to improve results on fixed tissues. Detection of p53 was different for each antibody: M 1801 detected 41 cases on frozen tissues, M-240 52 cases, M-421 28 cases. Using all the antisera, and the rabbit antiserum CM1, it was possible to detect 71 cases (36%). The percentage was the same in infiltrating lobular carcinomas but higher (94%) in medullary carcinomas. p53 was associated with high grade and ER-tumours. In formalin-fixed tissues, p53 had no prognostic value. In frozen tissues p53 was not an independent factor of prognosis. However, it was important in sorting out cases with bad prognosis in the ER-carcinomas and in the carcinomas without metastases. The prognostic value was different for each monoclonal antiserum. Positivity with M421 associated with negativity for M240, and positivity only for M1801 sorted out cases with a poor prognosis (67% and 50% deaths at 5 years).

Hormonal receptors and markers for prognostic evaluation were detected immunohistochemically in 196 infiltrating ductal breast carcinomas. Immunohistochemical detection of progesterone and oestrogen receptor is a method giving results generally concordant with those of the binding assay. However, immunohistochemical detection seems better. It allows the detection of hormonal receptors on small carcinomas, it is not modified by the endogenous hormones, and it has a slightly better correlation with prognosis and with the response to hormone therapy. Immunohistochemical detection of progesterone receptor has a prognostic value, sorting a negative subgroup with a poor prognosis from the oestrogen receptor positive tumours. These results can be obtained without quantitative immunohistological methods. ERD5, pS2, HSP27 and cathepsin D are associated with oestrogen receptor positivity. pS2 and HSP27 are interesting markers. They characterize a subgroup of oestrogen receptor negative tumours with a good prognosis. Moreover, pS2 is a marker of response to hormone therapy. ERD5 and cathepsin D do not appear to be of value as markers of prognosis.

Zinc-alpha2-glycoprotein, gross cystic disease fluid protein 15, and estrogen receptors are expressed in a great proportion of breast carcinomas. These markers were investigated by immunohistochemistry in 28 metastases from breast carcinomas and for comparison on 24 metastases from other carcinomas. A group of 83 primary nonmammary tumors was also studied. Most (> 96%) breast carcinoma metastases expressed one or several markers, while all metastases of other origins were negative. This sensitive and apparently specific immunostaining proved to be of great utility in cases in which the mammary origin of metastases was difficult to establish. In four axillary lymph node metastases, it even led to the discovery of an occult homolateral breast carcinoma that was not detectable by clinical and mammographic investigations. This study indicates that the combined use of zinc-alpha2-glycoprotein, gross cystic disease fluid protein 15, and estrogenic receptors represents a useful immunostaining technique that can help the pathologist in determining the origin of breast carcinoma metastases.

The etiology of esophagus papilloma is much debated: some authors attach greater importance to irritation factors, while others give preference to the viral hypothesis and suggest that this disease could eventually lead to squamous cell carcinoma of the esophagus. To verify the viral hypothesis, we reviewed the histological slides of the 33 cases of esophageal papilloma diagnosed in our Institute of Pathology between 1973 and 1988. We evaluated the histological diagnosis using WINCKLER'S criteria. HPV typing was done using probes of HPV DNA types 6-11, 16-18, 31-33-35 applied to paraffin sections according to the in-situ hybridization method. Clinical and endoscopic data of 15 cases (from the CHUV) are reviewed. Oncological data was provided by the Vaud Cantonal Tumor Register. No patient in our series fulfilled all the histological criteria set by WINCKLER to diagnose an HPV condition. Viral DNA 31-33-35 was found in a small minority of the papillomas. The clinical impact of esophageal papilloma on epidermoid carcinogenesis is nil.

The phenotype of 165 gastrointestinal stromal tumours was studied by immunohistochemistry. In each case the phenotype was compared to the histological diagnosis. The phenotype was muscle in 49 tumours (30%), neural in 18 (11%), histiocytic in 20 (12%) and mixed in five (3%); 68 tumours (41%) were positive for vimentin only, four tumours had no markers and one tumour was positive for keratin only. Histologically, the tumours were classified as smooth muscle, probably smooth muscle, probably nerve sheath tumours or tumours of undetermined differentiation, In 30 istologically unequivocal muscle tumours, the phenotype was muscle in 28. Half of them, all benign, arose in the oesophagus or gastric cardia. Apart from this group, there was no correlation between phenotype, site of tumour and histological differentiation. Actin was a more sensitive muscle marker than desmin. With the exception of oesophageal tumours, the histological appearances alone could not establish a diagnosis of malignancy and were inadequate in evaluating differentiation. Immunohistochemical examination determined differentiation in 54% of the tumours, but this finding should be interpreted with caution in terms of histogenesis. It allowed us. however, to specify the differential diagnosis in 57 tumours in which the histological diagnosis was uncertain.

Immunohistochemical techniques were used to study 177 hepatic tumors (hepatocarcinoma, cholangiocarcinoma, hepatocholangiocarcinoma, adenocarcinoma of unknown origin, and metastatic carcinoma). Phenotypes suggestive of hepatocarcinoma included keratins 8 and 18, factor XIII a, alpha-fetoprotein. C-reactive protein, carcinoembryonic antigen (CEA) cross-reacting antigen; those in effect that excluded hepatocarcinoma were keratins 1, 5, 10, 11, 19, true CEA. C-reactive protein, used for the first time, proved to be a fairly sensitive and specific marker. Factor XIII a, which was thought to be synthesized only by histiocytes, was also present in hepatocytes. Immunohistochemistry appears to be an important tool in the diagnosis of hepatic tumors. As a result of this study, 32 cases were reclassified; several were found to be intermediate between hepatocarcinoma and cholangiocarcinoma. Sixteen cases apparently were true hepatocholangiocarcinomas. In 12 cases of hepatocarcinoma, some tumor cells expressed keratins of bile duct type. It was impossible to differentiate immunohistochemically cholangiocarcinoma from metastatic carcinoma, except in two cases with breast tissue markers.

The etiology of esophagus papilloma is much debated: some authors attach greater importance to irritation factors, while others give preference to the viral hypothesis and suggest that this disease could eventually lead to squamous cell carcinoma of the esophagus. To verify the viral hypothesis, we reviewed the histological slides of the 33 cases of esophageal papilloma diagnosed in our Institute of Pathology between 1973 and 1988. We evaluated the histological diagnosis using Winckler's criteria. HPV typing was done using probes of HPV DNA types 6-11, 16-18, 31-33-35 applied to paraffin sections according to the in-situ hybridization method. Clinical and endoscopic data of 15 cases (from the CHUV) are reviewed. Oncological data was provided by the Vaud Cantonal Tumor Register. No patient in our series fulfilled all the histological criteria set by Winckler to diagnose an HPV condition. Viral DNA 31-33-35 was found in a small minority of the papillomas. The clinical impact of esophageal papilloma on epidermoid carcinogenesis is nil.

It is currently assumed that before their invasive stages most squamous cell carcinomas of the esophagus (ESCC) are preceded by dysplastic changes and an in situ carcinomatous phase. Whereas the latter is bound to progress to invasiveness, dysplasia, graded into mild, moderate and severe, is possibly still reversible, the reversibility being inversely related to the grade.

Cet article décrit les caractéristiques endoscopiques, cliniques et histo-pathologiques de 33 papillomes œsophagiens diagnostiqués à Lausanne entre 1973 et 1988, en les comparant aux données de la littérature (103 papillomes). Le papillome de l’cesophage est une lésion rare, de faible dimension, le plus souvent unique et asymptomatique, sans rapport avec le reflux gastro-œsophagien. Les potentialités malignes de la lésion sont apparemment nulles, l’évolutivité faible et la récidive inexistante après exérèse complète. Les signes histologiques d’une lésion virale, recherchés par la technique des sondes biotinylées, sont peu fiables et la quantité de virus 31-33-35 décelée dans notre série est faible. En présence d’une lésion de ce type, le rôle essentiel de l’endoscopiste consiste à exclure la forme rare d’un carcinome « précoce » de type papillaire grâce à une coloration vitale et une biopsie-exérèse sélective. L’impact clinique du papillome œsophagien sur la carcinogenèse épidermoïde est nulle en Occident, étant donné la rareté de la lésion.

Columnar epithelium-lined esophagus, cahed Barrett’s esophagus is a comphcation of gastroesophageal reflux (GER) in 20% of cases. Columnar metaplasic mucosa is probably more frequent if hmited types of Barrett’s esophagus are included.

Two types of high grade dysplasia were associated with invasive carcinomas. The first, deeply localized, had a pagetoid appearance and a particular phenotype: the dysplastic cells had keratins of low molecular weight rarely present in the esophagus; keratins of stratified epithelia were absent. This dysplasia was probably the origin of undifferentiated invasive carcinoma with which it was often associated. The second type, transepithelial, extended through the entire thickness of the epithelium. The abnormal cells presented some differentiation and stained positive for keratins of stratified epithelia. This dysplasia was often associated with differentiated squamous cell carcinoma. An intermediate-type dysplasia shared some characteristics with both main types. Several types of dysplasia and several areas of differently differentiated carcinoma were often associated in the same case. The evolutional potential of the different dysplasias is not known.