H. Zhou

c‐KIT is frequently mutated in bilateral germ cell tumours and down‐regulated during progression from intratubular germ cell neoplasia to seminoma

Testicular germ cell tumours (TGCTs) are the most frequent cancer type in young men; 5% of these patients develop a second TGCT in the contralateral testis. The pathogenesis of TGCT is closely linked to primordial germ cells (PGCs) or gonocytes. The receptor tyrosine kinase (c‐KIT) is necessary for migration and survival of PGCs and is expressed in intratubular neoplastic germ cells (IGCNUs) and seminomas. We studied the frequency of c‐KIT exon 11 and 17 mutations in 155 unilateral (108 seminomas and 47 non‐seminomas) and 22 bilateral (18 seminomas, two embryonal carcinomas, two IGCNU) cases. While no mutations were detected in exon 11, the mutation frequency in exon 17 was significantly higher in bilateral (14/22, 63.6%) compared to unilateral TGCT (10/155, 6.4%) (p < 0.001). Different activating mutations (Y823D, D816V, D816H and N822K) were detected in bilateral TGCT. Y823D mutation was identical in both testes in three cases and quantitative pyrosequencing showed that up to 76% of the cells analysed in tumour samples carried this mutation. One bilateral synchronous seminoma revealed a S821F mutation in one testis and a Y823D mutation contralaterally. To study the role of c‐KIT in TGCT progression, we compared its expression in 41 seminomas and adjacent IGCNUs. Immunohistochemical analysis revealed that c‐KIT expression was significantly reduced in seminomas compared to IGCNUs (p < 0.006) and that there were no significant changes in c‐KIT mRNA copy numbers in progressed compared to low‐stage seminomas. In summary, our study shows that patients with c‐KIT mutations are more prone to develop a bilateral TGCT and suggests that in a portion of bilateral TGCTs, c‐KIT mutations occur early during embryonal development, prior to the arrival of PGCs at the genital ridge. Furthermore, our findings show that c‐KIT down‐regulation occurs during the progression of IGCNU to seminoma. Copyright

Diagnostic value of markers M2A, OCT3/4, AP‐2γ, PLAP and c‐KIT in the detection of extragonadal seminomas

Aims:u2002 To compare the suitability of new seminoma markers including transcription factors AP‐2γ, OCT3/4 and M2A for detection of metastatic and extragonadal seminomas with the two well‐known markers c‐KIT and PLAP.

Primitive neuroectodermal tumor (PNET) in the differential diagnosis of malignant kidney tumors.

Primitive neuroectodermal tumors (PNETs) of the kidney, a rare neoplastic disease of high malignancy with a tendency towards early metastasis, affect young adults (26-30 years) irrespective of the gender. Differential diagnosis from other renal tumors is very important for an effective therapy. Herein, we report on a 24-year-old male patient with a renal tumor consisting of small, round cells, and summarize the diagnostic procedures that establish the diagnosis of PNET. Light microscopy revealed not only areas containing small, round cells forming rosettes and pseudorosettes, but also areas containing spindle cells. Expression of CD 99 in combination with neural markers, such as NSE, was detected by immunohistochemistry, and further evidence of neural differentiation was provided by electron microscopy. Image cytometry revealed a peridiploid DNA-stemline. A reciprocal translocation of the chromosomes 11 and 22 [t(11;22)(q24;q12)] with expression of a EWS/FLI-1 fusion transcript was demonstrated by molecular pathology. Using these methods, the diagnosis of PNET was firmly established, and the tumor was treated by surgical resection and subsequent adjuvant chemotherapy. Eighteen months after therapy, the patient is in excellent health condition without any evidence of tumor recurrence.

Pathogenese und Histopathologie von Adenomen und Karzinomen der Papilla Vateri

ZusammenfassungDie Vater-Papille ist im Dünndarm und im Verlauf des Ductus choledochus der häufigste Entstehungsort von Adenomen und Karzinomen. Bei familiärer adenomatöser Polypose (FAP) ist sie Hauptsitz für Karzinome nach Proktokolektomie. Aufgrund früher stenosebedingter Symptome sind ca. 80% der Tumoren mit kurativer Intention chirurgisch angehbar. Die Operabilität ist der wichtigste Prognosefaktor; eine frühe Diagnose ist somit verlaufsentscheidend. Entzündung, regeneratorische Veränderungen und Fibrose nach endoskopischen Eingriffen, begleitende Hyperplasie, adenomatöse Vorläufer und tiefer Sitz mancher Papillenkarzinome erschweren die Karzinomdiagnose am Biopsiematerial. Als histologische Haupttypen lassen sich das intestinal und das pankreatobiliär differenzierte Papillenkarzinom unterscheiden. Hinzu kommen nicht weiter differenzierbare Karzinome und Sonderformen. Im eigenen Kollektiv 45 operierter Papillenkarzinome wiesen 6 der 10 Tumoren des intestinalen Typs und 4 Tumoren mit Sonderformen das Markerprofil intestinaler Schleimhaut auf (Keratin 7−, Keratin 20+, MUC2+). 17 von 21 Tumoren des pankreatobiliären Typs, alle 4 undifferenzierten Karzinome und 3 papilläre Karzinome zeigten das Markerprofil pankreatobiliärer Gangschleimhaut (Keratin 7+, Keratin 20−, MUC2−). Bei 3 mit diesen Marker nicht reagierenden Karzinome zeigten nichtinvasive Vorläuferläsionen eine der beiden Markerkombinationen. Diese Befunde unterstreichen das Konzept histogenetisch unterschiedlicher Papillenkarzinome, die vom intestinal oder vom pankreatobiliär differenzierten Schleimhautanteil der Vater-Papille ausgehen. Die Molekularpathogenese des Papillenkarzinoms ähnelt einerseits der des kolorektalen Karzinoms, andererseits des duktalen Pankreaskarzinoms, doch bestehen Unterschiede in der Häufigkeit der molekularen Alterationen. Zukünftige molekularpathologische Untersuchungen des Papillenkarzinoms sollten auf einer histologischen Klassifikation gründen, die die Histogenese des Papillenkarzinoms aus den 2 verschiedenen Schleimhauttypen der Papilla Vateri konsequent berücksichtigt.AbstractMost adenomas and carcinomas of small intestine and extrahepatic bile ducts arise in the region of Vaters papilla. In FAP it is the main location for carcinomas after proctocolectomy.In many cases symptoms due to stenosis lead to diagnosis in an early tumor stage. In about 80% curative intended resection is possible. Operability is the most relevant prognostic factor. Inflammatory changes, fibrosis, regeneratory changes after endoscopic manipulation, hyperplasia, preneoplastic lesions close to carcinoma, deeply sited carcinomas under protruded, non-neoplastic duodenal mucosa make the diagnosis difficult on biopsy material. Histologically, intestinal type adenocarcinoma, pancreatobiliary type adenocarcinoma, undifferentiated carcinomas and unusual types can be differentiated. In our own series comprising 45 resected ampullary carcinomas 6 from 10 intestinal type adenocarcinomas, and 4 carcinomas of unusual types expressed the immunohistochemical marker profile of intestinal mucosa (keratin 7−, keratin 20+, MUC2+). 17 from 21 pancreatobiliary type adenocarcinomas, 4 undifferentiated carcinomas, as well as 3 papillary carcinomas showed the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20−, MUC2−). 3 invasive carcinomas which were negative for these markers, showed one of these characteristic marker-combinations in non-invasive adenomatous parts. These findings support the concept of histogenetically different ampullary carcinomas which are developing from the intestinal or from the pancreaticobiliary type mucosa of Vaters papilla. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear in different frequencies. In future studies molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. The histologic classification should reflect consequently the histogenesis of ampullary tumors from the two different types of papillary mucosa.

Acute adenoviral infection of a graft by serotype 35 following renal transplantation

Adenoviral infections of immunocompetent patients usually present as self-limiting pharyngitis, gastroenteritis, urocystitis, or conjunctivitis. In immunosuppressed patients, development of the illness can be severe, even life-threatening or fatal, and therapeutical intervention is difficult. Previous case reports of adenoviral infections after kidney transplantation have described a symptomatology of hemorrhagic cystitis, fever, renal dysfunction, and rarely fatal systemic dissemination. Here we report on a 46-year-old female renal transplant recipient suffering from adenoviral serotype 35 nephritis of the donor organ 29 days after transplantation. In this case, the main symptoms of the adenoviral infection were high fever and progressive renal failure of the transplanted organ. At the peak of the clinical symptoms, owing to histological and immunohistochemical evaluations of a kidney biopsy, we were able to establish the diagnosis in time so that adequate therapy could be employed. Immunosuppression was reduced and modified, and a self-limiting course of the infection was observed, followed by significant improvement of graft function. Subsequent to histological diagnosis, adenoviral particles were isolated from urine and identified as adenovirus serotype 35. Adenoviral nephritis of the transplanted organ should be considered in the differential diagnosis of persistent anuria after kidney transplantation. Our case highlights the importance of applying all possible diagnostic techniques, including histological evaluation of renal biopsies.

CD56 expression aids in the differential diagnosis of cholangiocarcinomas and benign cholangiocellular lesions

CD56 (neuronal cell adhesion molecule, N-CAM) has been reported in neuroendocrine tumours and as a marker of reactive biliary epithelial cells. However, up to date, it is not used to distinguish malignant from non-malignant biliary lesions. In this study, we systematically examined CD56 expression on 98 tumours arising from the biliary tree as well as intrahepatic conditions with reactive neoductules. When neuroendocrine carcinomas are excluded, only 4 of 32 (12.5%) cholangiocarcinomas expressed CD56, 2 of which showed clear cell morphology. Reactive bile ductules adjacent to cirrhotic nodules as well as in focal nodular hyperplasia were CD56 positive. Twelve of 17 (70.5%) bile duct adenomas were CD56 positive, whereas von Meyenburg complexes expressed CD56 only very focally in less than 5% of lesional cells. Bile duct cysts were negative for CD56 with the exception of focally interspersed neuroendocrine cells, similar to that seen in segmental bile ducts. Thus, if van Meyenburg complexes are excluded, CD56 can be used to differentiate intrahepatic non-neoplastic from neoplastic proliferations, which is a helpful diagnostic tool in small liver biopsies.

Leberparenchymknoten bei pathologischer hepatischer Vaskularisation/Perfusion

ZusammenfassungDie noduläre regenerative Hyperplasie (NRH) ist durch einen bindegewebsarmen, nichtzirrhotischen kleinknotigen Leberumbau gekennzeichnet. Ihr liegen kleinste Portalvenenverschlüsse zugrunde. Makroregenerative Knoten in nichtzirrhotischer Leber entstehen in arteriell hyperperfundierten Parenchymbereichen in ansonsten minderperfundiertem Lebergewebe bei Lebervenen- und/oder Portalvenenverschlüssen. Sie können bilddiagnostisch einen malignen Tumor vortäuschen, ähneln morphologisch einer fokalen nodulären Hyperplasie (FNH) und sind von Adenomen anhand duktulärer Strukturen entlang von Septierungen unterscheidbar. Nach extrahepatisch systemisch bedingter Ursache der Perfusionsstörung ist zu fahnden. In Zirrhosen sind makroregenerative Knoten aufgrund zytologischer und mikroarchitektureller Kriterien gegenüber dysplastischen Knoten und dem hepatozellulären Karzinom (HCC) abzugrenzen. Die FNH kann im Biopsat eine Zirrhose, Steatohepatitis, chronische Hepatitis oder Cholangitis imitieren, wenn nicht umgebendes Normalgewebe miterfasst ist. Die teleangiektatische FNH ähnelt bei geringer Septierung und spärlichen neoduktulären Strukturen dem Leberzelladenom. Die großherdige neoduktuläre Parenchymtransformation hypoperfundierter Parenchymareale ist von Cholangiomen und Cholangiokarzinomen abzugrenzen.AbstractNodular regenerative hyperplasia (NRH) is characterized by a non-cirrhotic micronodular transformation of the liver parenchyma. It is based on the obliteration of small portal veins. Macroregenerative nodules (MRN) develop in areas of favourable blood flow in otherwise hypoperfused liver tissue. Hypoperfusion is caused by obliteration of liver veins and/or large portal veins with the subsequent atrophy or extinction of parenchyma. The hyperperfused and sometimes rapidly growing MRN might simulate a malignant tumor in CT and MRT. Morphologically, MRN resemble FNH. In contrast to hepatocellular adenoma, they show a more or less nodular architecture with fibrous septa and ductular structures. NRH and cases of MRN without cirrhosis can indicate an extrahepatic/systemic disease causing altered liver perfusion. MRN in liver cirrhosis must be differentiated from dysplastic nodules and highly differentiated hepatocellular carcinoma by cytological and microarchitectural criteria. Focal nodular hyperplasia (FNH) can imitate liver cirrhosis, steatohepatitis, cholangitis or chronic hepatitis, if biopsy material does not include normal perilesional liver tissue. Telangiectatic FNH might resemble classic hepatocellular adenoma. Neoductular structures and septation argue for this rare subtype of FNH. Neoductular transformation of hypoperfused liver parenchyma might imitate cholangioma or cholangiocarcinoma.

Primary extragonadal germ cell tumour: unusual localization of a c-kit mutated retroperitoneal seminoma in the gastric wall.

degree of epithelial proliferation; Type I (florid type) is characterized by an increase in the number of ducts with irregular lumens and three or more epithelial cell layers often with small papillae and usually surrounded by loose connective tissue, well demarcated from the surrounding stroma. Type II (quiescent type) is characterized by slightly increased numbers of ducts with little or no proliferation of the epithelium and no expansion of connective tissue stroma surrounding the ducts. The histological appearances probably relate to the duration of the gynaecomastia. Observations of a higher incidence of male breast cancer in areas with high frequencies of gynaecomastia, and significantly increased frequencies of breast cancer in patients with Klinefelter’s syndrome have previously been noted suggesting that in some cases gynaecomastia may be a premalignant state. In keeping with this, Bannayan et al. found a variety of atypical histological findings following the review of 351 cases of histologically proven gynaecomastia (335 surgically removed and the remainder diagnosed at autopsy). Atypical ductal hyperplasia was seen in 15 cases, atypical lobular hyperplasia in three cases and intraductal carcinoma in four. Most of the atypical hyperplasias and the cancer cases were associated with gynaecomastia of the florid type as in our case. In a series of 100 unselected, consecutive male autopsies reviewed by Anderson and Jorgen there were 55 (55%) cases with gynaecomastia. In seven (7%) there were changes described as severe epithelial hyperplasia of the ‘atypical – early in situ carcinoma type’; five of these were in cases diagnostic or suspicious of gynaecomastia. In four of the seven cases the epithelial hyperplasia was described as cribriform with abnormal nuclear polarization. Nuclei were generally rounded but not very hyperchromatic and only a few mitoses were seen. In the other three cases there were pagetoid changes with many intracytoplasmic lumina and it was uncertain whether this represented ductal or lobular neoplasia. The reviewers cautioned against over-interpretation of such findings in surgical cases of gynaecomastia emphasizing the detailed nature of their studies. They also suggested it was unlikely that gynaecomastia was a premalignant state given the presence of similar changes in cases with gynaecomastia and cases where the breast tissue was histologically normal. In keeping with this, a review of 233 cases of surgically removed gynaecomastia by Cole and Quizilbash failed to detect any evidence of neoplasia. They also examined 32 male breast cancer specimens, only one of which revealed microscopic changes of gynaecomastia. Additionally, there were no cases of male breast cancer in a recent cohort Swedish study in which 445 cases of surgically removed and histologically proven gynaecomastia were followed for 30 years. In conclusion, the evidence suggests that if there is an association between gynaecomastia and breast cancer, then the link is weak and the risk is low. Identification of a possible higher level of risk in cases such as this, however, requires formal reporting and, when possible, detailed investigation with the collection of meaningful cohorts and follow-up data.

Leberveränderungen bei heterozygotem α1-Antitrypsin-Mangel PiZ

ZusammenfassungBisher ist umstritten, ob heterozygote Patienten mit α1-Antitrypsin (AAT)-Mangel Typ PiZ ein erhöhtes Risiko für Lebererkrankungen aufweisen. An Leberproben von 1030 Autopsien (Autopsie-Serie), 1847 Biopsien (Biopsie-Serie) und 317 primären Leberkarzinomen (Tumor-Serie) sollte der Einfluss des heterozygoten PiZ-Status auf die Leber untersucht werden. Die PiZ-Bestimmung erfolgte immunhistochemisch, teilweise ergänzt durch SSCP-Analyse und DNA-Sequenzierung von DNA-Extrakten aus paraffineingebettetem Material.Die PiZ-Häufigkeit der Biopsie-Serie (3,4%) und der Tumor-Serie (5,99%) war signifikant höher als die der Autopsie-Serie (1,8%). PiZ-Ablagerungen waren bei manchen heterozygoten Merkmalsträgern ebenso umfangreich wie bei homozygoten. Ihr Ausmaß korrelierte positiv mit Entzündungsaktivität und Fibrosegrad der Leber sowie mit dem Patientenalter. Patienten mit konkurrierenden Lebererkrankungen wie Hepatitis oder Alkoholschädigung wiesen eine signifikant stärkere Entzündung, Fibrose und mehr PiZ-Ablagerungen auf als diejenigen ohne zusätzliche Lebererkrankungen. Cholangiokarzinome und kombinierte Hepatocholangiokarzinome traten signifikant häufiger bei Patienten mit PiZ-Mutation als bei genetisch Gesunden (p=0,004) auf. Nur 3 der 19 PiZ-assoziierten Leberkarzinome waren in einer Leberzirrhose entstanden.Patienten mit heterozygotem AAT-Mangel Typ PiZ tragen nach den hier vorgestellten Ergebnissen ein erhöhtes Risiko für chronische Lebererkrankungen einschließlich primärer Leberkarzinome. Wenn überhaupt, manifestiert sich dieser genetische Defekt erst in mittlerem oder höherem Lebensalter. Er kann in seltenen Fällen selbst ohne konkurrierende Lebererkrankung zur Zirrhose führen. PiZ-assoziierte Leberkarzinome sind häufig cholangiozellulär differenziert und entstehen mehrheitlich ohne Leberzirrhose. Hepatische PiZ-Ablagerungen lassen sich immunhistochemisch zuverlässig identifizieren.AbstractWhether heterozygotes with alpha-1-antitrypsin (AAT) deficiency type PiZ bear an increased risk for chronic liver disease is controversial. On the basis of liver tissue from 1,030 autopsies (autopsy series), 1,847 biopsies (biopsy series) and 317 primary liver carcinomas (tumor series), we analysed the effect of heterozygous state PiZ for the development of liver diseases. The PiZ status was screened immunohistochemically and verified in selected cases by SSCP analysis and by sequencing DNA extracted from paraffin embedded tissue.The PiZ frequency in the biopsy series (3.4%) and tumor series (5.99%) was significantly higher than in the autopsy series (1.8%). Hepatic PiZ deposits in heterozygotes sometimes were as extensive as in homozygotes. The amount of PiZ deposits correlated positively with the inflammatory activity and stage of fibrosis, as well as with the age of patients. Patients with concurrent liver disease such as hepatitis and alcoholic liver disease showed significantly higher scores of inflammatory activity, stage of fibrosis and amount of PiZ deposits than those without additional liver disease. Cholangiocarcinomas and combined hepato-cholangiocarcinomas were seen significantly more frequently in patients with PiZ-associated liver carcinoma than in genetic healthy individuals (p=0.004). Three out of 19 PiZ-associated liver carcinomas had developed in cirrhotic liver tissue.Heterozygotes of type PiZ have an enhanced risk for chronic liver disease including primary liver carcinoma. PiZ-associated liver diseases will become clinically manifest in middle or old aged adults. Rarely this genetic defect causes liver cirrhosis even without concurrent liver disease. PiZ-associated liver carcinomas are frequently characterized by cholangiocellular differentiation and may develop often in non-cirrhotic liver tissue. Immunohistochemistry is a specific method to detect hepatic PiZ deposits.

Molekulare Pathologie der testikulären Keimzelltumoren: ein Update

ZusammenfassungKeimzelltumoren (KZT) stellen eine heterogene Gruppe von benignen und malignen Tumoren dar. Basierend auf ihren unterschiedlichen biologischen Fähigkeiten und ihrer Herkunft werden KZT in 5xa0verschiedene Gruppen eingeteilt. Maligne seminomatöse und nichtseminomatöse KZT in beiden Geschlechtern bilden die Gruppe der Typ-II-KZT. Ihre häufigsten Vertreter sind die testikulären malignen KZT. Typ-II-KZT zeigen große Übereinstimmungen mit embryonalen Stammzellen. Die unklassifizierte intratubuläre Keimzellneoplasie (IGCNU), die Vorläuferläsion der KZT Typxa0II, entwickelt sich aus persistierenden unreifen fetalen Keimzellen, Gonozyten, die sich einem normalen Differenzierungsprozess entziehen. Dabei wird postuliert, dass Exon-17-aktivierende Mutationen der Rezeptortyrosinkinase c-KIT sehr früh während der Keimzellentwicklung auftreten und dass Gonozyten mit aktiviertem c-KIT-Rezeptor in ihrer Differenzierung gehemmt werden und sich dadurch einer normalen Entwicklung entziehen. Neue diagnostische Marker für neoplastische Keimzellen wie OCT3/4 und AP-2γ werden spezifisch in IGCNU, Seminomen und embryonalen Karzinomen detektiert und können helfen, eine Keimzellneoplasie Typxa0II von anderen malignen Tumoren abzugrenzen.AbstractGerm cell tumors (GCT) comprise a heterogeneous group of benign and malignant tumors. Based on their different biological characteristics and their origin, five types of GCT are classified. Among these, malignant seminomatous and non-seminomatous GCT in males and females are designated as type II GCT. They occur most frequently as malignant testicular GCTs. Many characteristics of type II GCT can be linked to embryonic stem cells. Intratubular germ cell neoplasia, unclassified (IGCNU) is the precursor of type II GCT and derives from undifferentiated germ cells, gonocytes, which persist in the newborn testis and escape the normal differentiation process. It is suggested that Exon-17-activated mutations of the receptor tyrosine kinase, c-KIT, occur early in germ cell development and that gonocytes with an activated c-KIT receptor are restricted in their differentiation, thereby escaping normal development. New diagnostic markers for neoplastic germ cells, including OCT3/4 and AP-2γ, are specifically detected in IGCNU, seminomas and embryonal carcinomas and are helpful in the differentiation of type II GCT from other malignant tumors.