Female urethral adenocarcinoma with a heterogeneous phenotype. Case report

We here report a very rare case of female urethral adenocarcinoma. A 77-year-old woman presented with urinary retention. Cystoscopy showed a urethral tumor and the biopsy material showed adenocarcinoma. Macroscopically, the tumor measuring 3.0 x 3.0 x 2.4 cm was predominantly observed around the periurethral area on the proximal side. Histologically, patterns of columnar/mucinous adenocarcinoma, clear cell adenocarcinoma and papillary/micropapillary carcinoma were observed, but there was no evidence of a cribriform pattern. Immunohistochemically, neoplastic cells of at least one of three components were positive for CK7 and CK20 or CA125. We suggest that female urethral adenocarcinoma with a histologically and immunohistochemically heterogeneous phenotype may originate from cells within urethral or paraurethral tissue, such as urethritis glandularis or intestinal metaplastic epithelium and Mullerian tissue.

High-grade urothelial carcinoma of the renal pelvis: clinicopathologic study of 108 cases with emphasis on unusual morphologic variants

A clinicopathologic study of 108 cases of high-grade urothelial carcinomas of the renal pelvis is presented. Of the 108 tumors, 44 (40%) showed unusual morphologic features, including micropapillary areas (four cases), lymphoepithelioma-like carcinoma (two cases), sarcomatoid carcinoma (eight cases, including pseudoangiosarcomatous type), squamous differentiation and squamous cell carcinoma (15 cases), clear cells (two cases), glandular differentiation (two cases), rhabdoid, signet-ring or plasmacytoid cells (four cases), pseudosarcomatous stromal changes (four cases) and intratubular extension into the renal pelvis (three cases). Pathological staging was available in 62 patients; of these, 46 cases (74%) were in high stage (pT2-pT4) and 16 (26%) were in low stage (pTis, pTa, pT1). Clinical follow-up ranging from 1 to 256 months (median: 50 months) was available in 42 patients; of these, 26 (61%) died of tumor with a median survival of 31 months. The patients who did not die of their tumors showed only minimal or focal infiltration of the renal parenchyma by urothelial carcinoma, whereas those who died of their tumors showed massive infiltration of the kidney by the tumor. High-grade urothelial carcinomas of the renal pelvis can show a broad spectrum of histologic features similar to those seen in the urinary bladder. Our results support the finding that, unlike urothelial carcinomas of the bladder, the majority of primary urothelial carcinomas of the renal pelvis are of high histologic grade and present in advanced stages. Our study further highlights the fact that, in the renal pelvis, urothelial carcinomas show a tendency to frequently display unusual morphologic features and metaplastic phenomena. The importance of recognizing these morphologic variants of urothelial carcinoma in the renal pelvis is to avoid confusion with other conditions. The possibility of a high-grade urothelial carcinoma should always be considered in the evaluation of a tumor displaying unusual morphologic features in the renal pelvis, and attention to proper sampling as well as the use of immunohistochemical stains will be of importance to arrive at the correct diagnosis.

Krukenberg Tumor of Renal Pelvic Origin: Report of a Case With Selected Comments on Ovarian Tumors Metastatic From the Urinary Tract

Metastatic tumors to the ovary are infrequently of urinary tract origin. In approximate descending order of frequency, this subset of secondary ovarian neoplasms includes renal cell carcinoma, transitional cell carcinoma of the urinary bladder, and urachal adenocarcinomas. These tumors usually raise a differential in turn of primary ovarian clear cell, transitional cell, or mucinous carcinomas. Only rare metastatic signet-ring adenocarcinomas of the bladder have shown the features of a Krukenberg tumor. We report the case of a 74-year old woman with bilateral Krukenberg tumors metastatic from a primary renal pelvic transitional cell carcinoma with glandular and signet-ring cell differentiation. This unique case reinforces that tumors with signet-ring cell morphology have a propensity to metastasize to the ovary, and indicates that renal pelvic carcinoma rarely may be the source of Krukenberg tumors.

Differences in clinicopathological and biological features between central-type and peripheral-type squamous cell carcinoma of the lung

The central type and peripheral type squamous cell carcinoma (SCC) of the lung have different clinicopathological characteristics, but, little is known about their biological characteristics. We investigated differences between the properties and phenotypes of peripheral-type (P-type) and central-type (C-type) SCC by performing an immunohistochemical analysis of each type by tissue microarray analysis with a large panel of antibodies. To examine strictly, we selected 20 P-type SCCs that were pathological stage T1 and limited to more peripherally than the fifth bronchial bifurcation, and 21 C-type SCCs that were pathological stage T1 and limited to a lobar bronchus. The results of the clinicopathological study showed that the patients with P-type SCC were significantly older than the patients with C-type SCC and that squamous metaplasia was predominant in C-type SCC than in P-type SCC. The 36 antibodies revealed different expression patterns of cytokeratin 7 (CK 7) and cytokeratin 19 (CK 19) between C-type and P-type SCC. CK 7 expression was more predominant in P-type SCC than in C-type SCC, and CK 19 expression was more predominant in C-type SCC than in P-type SCC. These results suggest that C-type and P-type SCC have different clinicopathological and biological features.

Cytokeratin 20 expression identifies a subtype of pancreatic adenocarcinoma with decreased overall survival

BACKGROUND

Cytokeratins are markers of epithelial cell differentiation useful in determining histogenesis for malignancies with an unknown primary. Application of this principle to a single malignancy may identify cancer subtypes with altered developmental programs. Herein, we investigate the relevance of two widely used cytokeratins (CKs), 7 and 20, to subtype pancreas cancer and identify associations with clinical features.

METHODS

A tissue microarray was constructed using tumor specimens from 103 patients who underwent resection for pancreatic adenocarcinoma with curative intent. A subset of resection specimens was evaluated for pancreatic intraepithelial neoplasia (PanIN) lesions. Tissues were immunostained by using specific anticytokeratin 7 and 20 monoclonal antibodies.

RESULTS

CK 7 and 20 expression was present in 96% and 63% cases of pancreatic adenocarcinoma, respectively. Ubiquitous CK 7 expression precluded further analysis. Tumoral CK 20 expression was not associated with any histopathologic parameter but correlated with worse prognosis when considered as either a dichotomous (P=0.0098) or continuous (P=0.007) variable. In a multivariate model, tumoral CK 20 expression remained a significant independent prognosticator. CK 20 expression was absent in all PanIN lesions from eight resection specimens in which the tumor component was negative for CK 20. In contrast, presence of tumoral CK 20 was highly concordant with its expression in corresponding PanINs.

CONCLUSIONS

CK 20 expression defines a subtype of pancreas cancer with important biologic properties. When present, CK 20 expression is an early event in pancreatic carcinogenesis identifiable in precursor lesions. Further studies to identify the underlying genetic changes associated with this altered developmental pathway are warranted.

Murine CD200+ CK7+ trophoblasts in a poly (I:C)-induced embryo resorption model

Cytokeratin 7 (CK7) is currently regarded as the best marker for trophoblast cells, while CD200 (OX-2), known as 'tolerance signal', plays an important role in normal pregnancy. In this study, the status of CD200 expression was investigated in BALB/c x C57BL/6 and BALB/c x BALB/c mating combinations designed as allogeneic and syngeneic murine models of induced embryo resorption, in which the resorption rate was boosted by an i.p. injection of poly (I:C), a synthetic double-stranded RNA. The percentage of CD200+ cells in the CK7+ cell population (CD200+ CK7+ percentage) and the absolute number of these cells were determined with flow cytometry, using trophoblast cells collected at day 8.5 and day 13.5 of gestation. The potential effect of poly (I:C) on CD200 expression was also evaluated by detecting the CD200+ CK7+ percentage in trophoblast cells incubated in the presence or absence of poly (I:C), in vitro. The distribution pattern of CD200+ cells at the feto-maternal interface was evaluated by immunocytochemical examination. When 10(4) cells were analyzed at day 8.5 of gestation in each case, no significant difference was observed between the poly (I:C)-treated group and the control PBS group either in the CD200+ CK7+ percentage or in the absolute number of these cells. Similar results were observed both in BALB/c x C57BL/6 mice and in BALB/c x BALB/c mice. However, the CD200+ CK7+ percentage was significantly decreased in the poly (I:C)-treated group when evaluated at day 13.5 of gestation. Accordingly, a dramatically elevated rate of embryo resorption was observed at this time point of pregnancy after the administration of poly (I:C). In addition, the CD200+ CK7+ percentage was significantly lower in trophoblast cells incubated with poly (I:C) at a certain concentration, in vitro, while histocytochemical examination showed the CD200+ cells mainly scattered in placental tissue adjacent to the interface of the placenta and uterus. This indicates that sufficient expression of the CD200 molecule on CK7+ cells at the feto-maternal interface may be necessary for the maintenance of embryos during pregnancy in this rodent model, while poly (I:C) administration may increase embryo resorption, at least partially via direct inhibition of CD200 expression on CK7+ cells.

Multicystic biliary hamartoma

In this report, we presented 3 cases of unusual hamartomatous nodules of the liver. These nodules were located around hepatic capsule of the left hepatic lobe and characteristically protruded from the liver. Histologically, these nodular lesions consisted of ductal structures, periductal glands, and fibrous connective tissues containing blood vessels. Smooth muscle bundles focally surrounded ductal structures. Bile-like materials were observed within some ducts. Two cases were associated with xanthogranulomatous inflammation around bile-like materials, and this inflammatory process extended from ductal lumens to periductal connective tissues. In contrast, the remaining case, which was not associated with inflammation, showed a honeycomb appearance. Ductal epithelium and periductal glands resembled biliary epithelium and peribiliary glands, respectively, and they also expressed biliary-type cytokeratins such as cytokeratins 7 and 19. These nodules shared pathologic characteristics of ciliated hepatic foregut cysts, such as their location (around the falciform ligament) and periductal smooth muscle bundles, but did not fulfill the diagnostic criteria (no ciliated cells and multilocular lesions). These hamartomatous nodules of the liver did not fit into any of the described categories of hepatic nodular lesions. At present, we speculate that these lesions might be related to developmental abnormalities of the biliary tract or embryonal foregut.

Caveolin-1 immunohistochemical analysis in differentiating chromophobe renal cell carcinoma from renal oncocytoma

Chromophobe renal cell carcinoma (ChRCC) and oncocytoma might mimic each other histologically. We studied the immunohistochemical staining pattern of caveolin-1 in 21 ChRCCs and 26 oncocytomas and compared it with cytokeratin (CK) 7 to evaluate its usefulness in differentiating these 2 neoplasms. All 21 ChRCCs (100%) were positive for caveolin-1, 20 of which were stained in 20% or more of the tumor cells. In contrast, only 3 (12%) of 26 oncocytomas showed positivity in fewer than 20% tumor cells and 23 (88%) of 26 were negative. In the nonneoplastic kidney, positive caveolin-1 staining was detected in the interstitial blood vessels and the parietal cells of the Bowman capsules but not in the tubular epithelium and glomerular and peritubular capillaries. All 21 ChRCCs (100%) were positive for CK7, with 18 (86%) stained in 20% or more of the tumor cells and 3 (14%) in fewer than 20%. Of 26 oncocytomas, 25 (96%) were positive for CK7, with 7 (27%) stained in 20% or more of the tumor cells and 18 (69%) in fewer than 20%. These results strongly suggest that caveolin-1 immunohistochemical analysis is useful for differentiating ChRCC from oncocytoma and is superior to CK7.

Claudin-4 differentiates biliary tract cancers from hepatocellular carcinomas

The recently identified claudins are dominant components of tight junctions, responsible for cell adhesion, polarity and paracellular permeability. Certain claudins have been shown to have relevance in tumor development, with some of them, especially claudin-4, even suggested as future therapeutic target. The aim of the present study was to analyze the expression of claudin-4 in the biliary tree, biliary tract cancers and hepatocellular carcinomas. A total of 107 cases were studied: 53 biliary tract cancers, 50 hepatocellular carcinomas, 10 normal liver and 10 normal extrahepatic biliary duct samples. Immunohistochemical analysis was performed on conventional specimens and on tissue microarrays as well. Claudin-4 was further investigated by Western blot analysis and real-time RT-PCR. Intense membranous immunolabeling was found for claudin-4 in all biliary tract cancers unrelated to the primary site of origin, namely intrahepatic, extrahepatic or gallbladder cancers. Normal biliary epithelium showed weak positivity for claudin-4. In contrast, normal hepatocytes and tumor cells of hepatocellular carcinomas did not express claudin-4. The results of Western immunoblot analysis and real-time RT-PCR were in correlation with the immunohistochemical findings. Cytokeratins, as CK7 (92%) and CK19 (83%) were mostly positive in biliary tract cancers, however, one-third of hepatocellular carcinomas also expressed CK7 (34%). HSA antibody (HepPar1) reacted with the majority of hepatocellular carcinomas (86%), while being positive in a low percentage of the biliary tract cancers (8%). In conclusion, this is the first report of a significantly increased claudin-4 expression in biliary tract cancers, which represents a novel feature of tumors of biliary tract origin. Claudin-4 expression seems to be a useful marker in differentiating biliary tract cancers from hepatocellular carcinomas and could well become a potential diagnostic tool.

Mesothelioma with rhabdoid features: an ultrastructural and immunohistochemical study of 10 cases

Mesotheliomas with rhabdoid morphology are rare and only two individual case reports have been documented in the literature. This author reports a series of 10 cases of mesotheliomas with rhabdoid features, nine of which originated in the pleura and one in the peritoneum. Eight of the patients were men and two were women. Six patients had a history of asbestos exposure. Histologically, seven of the mesotheliomas were epithelioid, two sarcomatoid, and one biphasic. The proportion of the rhabdoid cells seen in these cases constituted 15-75% of the individual tumors. Cytoplasmic staining in the rhabdoid cells was seen for pan-keratin and vimentin in all 10 cases, for keratin 7 in eight of eight, for calretinin in nine of 10, and for keratin 5/6 in seven of nine. Nuclear positivity for WT1 was observed in the rhabdoid cells of four of seven cases and membranous reactivity for mesothelin in four of six, and for podoplanin in two of six. Only one case showed desmin positivity in sparse cells in the nonrhabdoid component of the tumor. All of the cases were negative for CEA, MOC-31, TAG-72, CD15, CD34, bcl2, muscle-specific actin, and TTF-1. Ultrastructural studies revealed paranuclear collections of intermediate filaments, but no evidence of rhabdomyoblastic differentiation was seen. The mean survival of five of the six patients for whom this information was available was 3.8 months. The remaining patient had a survival time of 1 year. It is important for pathologists to be aware that mesotheliomas can present rhabdoid features, not only because they can be confused with other malignancies that can exhibit a similar morphology, but also because of their apparently unusually aggressive behavior. The value of immunohistochemistry and electron microscopy in the differential diagnosis of these tumors is discussed.

PAX2: a reliable marker for nephrogenic adenoma

Nephrogenic adenoma is a rare lesion of the urinary tract. The diagnosis usually is straightforward when characteristic microscopic and clinical findings are present, and the entity is familiar. However, misdiagnosis, in particular of adenocarcinoma of the prostate gland, may occur. Immunohistochemical stains often are needed to make such a distinction, but currently available markers offered only partial help. It recently was demonstrated that nephrogenic adenoma in renal transplant patients originated from the renal tubular epithelium. This newly proved, but long sought information may be helpful in the differential diagnosis of nephrogenic adenoma. In this study, we investigated the expression of a renal transcription factor, PAX2, in 39 nonrenal transplant-related nephrogenic adenomas, 100 adenocarcinomas of the prostate gland, and 47 urothelial carcinomas of the urinary tract. A strong and distinct nuclear staining of PAX2 was found in all 39 cases of nephrogenic adenoma (100%), but not in normal prostate tissue, normal urothelium, adenocarcinomas of the prostate gland, and invasive urothelial carcinomas. Focal CD10 was detected in six of 13 nephrogenic adenomas in the superficial papillary component and in normal prostate epithelium, normal urothelium, lymphocytes, adenocarcinoma of the prostate gland, and urothelial carcinoma. There was no uroplakins detected in nephrogenic adenoma. Therefore, these findings are suggesting that nephrogenic adenoma in nonrenal transplant patients may also arise from the renal epithelium, as did the comparable lesions after transplantation. PAX2 is a specific and sensitive immunohistochemical marker in identification and differential diagnosis of nephrogenic adenoma.

Detection of fetal cells from transcervical mucus plug before first-trimester termination of pregnancy by cytokeratin-7 immunohistochemistry

AIM

The presence of fetal cells in the endocervical mucus of pregnant women was first reported in 1971. The uterine cavity is patent during the first trimester prior to fusion of amnion and chorion. Fetal cells from degenerating chorion frondosum are theoretically shed into the uterine cavity between seven and 13 weeks' gestation and are trapped in the transcervical mucus; they can be identified by immunohistochemistry.

METHOD

Ninety-nine transcervical mucosal plugs from pregnant women of between 7 and 13 weeks before abortion were collected, fixed, embedded, sectioned and stained with monoclonal antibody of cytokeratin-7 (CK-7) by immunohistochemistry.

RESULT

The identification of trophoblasts on each slide was defined according to positive staining and histologically chorionic villous similarity under microscopic examination, using the following five categories: none (1), less than five single positive-stained cells per-section (2), more than five single positive-stained cells per-section (3), clumps of positive-stained cells (4), and histological-like intact or fragmented chorionic villi (5). From amongst 71 samples that qualified for analysis, individual slides were evaluated and categorized into three groups, with the following results: 32 (45.1%) fell into group 1 (category 1) denoting a negative result, 10 (14.1%) fell into group 2 (category 2) indicating a possible positive result and 29 (40.8%) fell into group 3 (any combination of categories 3-5) representing a positive result.

CONCLUSIONS

Fetal cells, identified by CK-7, can be found in more than 59.2% of the transcervical mucus in early pregnancy by use of a minimally invasive sampling method. Prenatal diagnosis of single-gene or chromosome disorders may be possible in the pregnant transcervical mucus by use of modern molecular methods and they deserve further study.

Immunohistochemical distinction of intestinal-type sinonasal adenocarcinoma from metastatic adenocarcinoma of intestinal origin

OBJECTIVES

Distinction of intestinal-type sinonasal adenocarcinoma (ITAC) from adenocarcinoma of intestinal origin metastatic to the sinonasal cavity may be extremely difficult on histologic grounds alone. We studied the role of cytokeratin (CK) and mucin (MUC) expression in differentiating ITAC, metastatic adenocarcinoma of intestinal origin, and non-intestinal-type sinonasal adenocarcinoma (non-ITAC).

METHODS

We stained specimens from 5 cases of ITAC and 4 cases of non-ITAC, along with 4 colonic and 3 duodenal adenocarcinoma controls, with CK7 and CK20, MUC2 and MUC5, neuron-specific enolase (NSE), chromogranin (CHR), and carcinoembryonic antigen (CEA) in order to examine the possible combinations of markers that best aid in the diagnosis of these lesions. We also performed a retrospective review of our clinical experience with these rare lesions.

RESULTS

CK7 staining was positive in all ITAC and non-ITAC cases, whereas all cases displaying gastrointestinal-type differentiation (ITAC and metastatic intestinal cases) stained positive for both CK20 and MUC2. Staining for MUC5, NSE, CHR, and CEA was variable.

CONCLUSIONS

Tumors with the CK7+, CK20+, MUC2+ immunophenotype are likely primary sinonasal lesions, whereas tumors with the CK7-, CK20+, MUC2+ profile warrant further clinical evaluation to exclude metastatic disease from the gastrointestinal tract. Complete surgical resection of ITAC remains the mainstay of therapy.

Cyclooxygenase-2 expression is higher in ovarian cancer tissue adjacent to endometriosis than in ovarian cancer without comorbid endometriosis

OBJECTIVES

The purpose of this study was to examine if COX-2, CK7 and CK20 are involved in the malignant transformation of endometriosis.

METHODS

We compared COX-2, CK7 and CK20 expressions between isolated endometriosis lesions and endometriosis lesions adjacent to ovarian carcinoma and between isolated ovarian carcinoma and ovarian carcinoma with implants of endometriosis. Immunoreactivity was quantified using an immunohistochemical scoring system that corresponds to an image analysis-based system.

RESULTS

There was no difference in COX-2, CK7 and CK20 expressions between the isolated endometriosis lesions and the endometriosis lesions adjacent to ovarian carcinoma. Similarly, CK7 and CK20 were equally expressed between the isolated ovarian carcinoma and the ovarian carcinoma with implants of endometriosis. The COX-2 over-expression rate was greater in ovarian carcinoma that was associated with endometriosis than in isolated ovarian carcinoma (27.8% versus 5.6%, P = 0.083). In endometrioid type ovarian carcinoma, the difference in COX-2 expression was statistically significant (50% versus 0%, P = 0.023).

CONCLUSIONS

COX-2 over-expression may be a result of the malignant transformation of endometriosis to endometrioid type ovarian cancer or may represent an interaction between the two cellular components. With respect to cytokeratins, neither CK7 nor CK20 appear to be involved in the malignant transformation of endometriosis.

Combined immunohistochemistry of beta-catenin, cytokeratin 7, and cytokeratin 20 is useful in discriminating primary lung adenocarcinomas from metastatic colorectal cancer

Background

It is important to discriminate between primary and secondary lung cancer. However, often, the discriminating diagnosis of primary lung acinar adenocarcinoma and lung metastasis of colorectal cancer based on morphological and pathological findings is difficult. The purpose of this study was to evaluate the clinical usefulness of immunohistochemistry of β-catenin, cytokeratin (CK) 7, and CK20 for the discriminating diagnosis of lung cancer.

Methods

We performed immunohistochemistry of β-catenin, CK7, and CK20 in 19 lung metastasis of colorectal cancer samples, 10 corresponding primary colorectal cancer samples and 11 primary lung acinar adenocarcinoma samples and compared the levels of accuracy of the discriminating diagnosis by using antibodies against these antigens.

Results

Positive staining of β-catenin was observed in all the lung metastasis of colorectal cancer samples as well as in the primary colorectal cancer samples but in none of the primary lung acinar adenocarcinoma samples. Positive staining of CK7 was observed in 90.9% of the primary lung acinar adenocarcinoma samples and in 5.3% of the lung metastasis of colorectal cancer samples, but in none of the primary colorectal cancer samples. Positive staining of CK20 was observed in all the primary colorectal cancer samples and in 84.2% of the lung metastasis of colorectal cancer samples, but in none of the primary lung acinar adenocarcinoma samples.

Conclusion

Combined immunohistochemistry of β-catenin, CK7, and CK20 is useful for making a discriminating diagnosis between lung metastasis of colorectal cancer and primary lung acinar adenocarcinoma. This method will enable accurate diagnosis of a lung tumor and will be useful for selecting appropriate therapeutic strategies, including chemotherapeutic agents and operation methods.

Alpha-methylacyl-CoA racemase as a marker in the differential diagnosis of metanephric adenoma

Metanephric adenoma (MA), a well-described renal neoplasm, usually behaves in a benign fashion. It may have areas that are morphologically similar to papillary renal cell carcinoma (RCC) type, or epithelial (tubular predominant) type Wilms' tumor. Prior immunohistochemical studies of MA have reported variable staining patterns. Alpha-methylacyl-CoA racemase (AMACR), a molecular marker for prostate carcinoma, has subsequently been found to be overexpressed in breast, colorectal and ovarian cancers, among others. Recent microarray analysis of renal tumors has shown an increase of AMACR mRNA levels in papillary RCC but not in other subtypes. We investigated the utility of immunohistochemical staining for AMACR, cytokeratin 7(CK7), CD57 and WT1 to differentiate between the above-mentioned three neoplasms. Immunohistochemical stains were performed on paraffin-embedded tissue sections from 25 papillary RCC, 10 MAs and eight Wilms' tumors. AMACR was positive in one (10%) of 10 MAs and 24 (96%) of 25 papillary RCC, while it was negative in all Wilms' tumors. CK7 was positive in 20 of 25 papillary RCCs, focally positive in one Wilms' tumor and was negative in all MAs. CD57 was positive in all six MAs that were stained, focally positive in one of 25 papillary RCC and one of eight Wilms' tumors. WT1 was positive in seven of 10 MAs, three of 25 papillary RCCs and all eight Wilms' tumors. In conclusion, diffuse and strong immunoreactivity for AMACR may be useful in differentiating papillary RCC from MA but a panel which includes AMACR, CK7 and CD57 is better in this differential diagnosis. AMACR is not helpful in differentiating MA from Wilms' tumor, but CD57 is helpful in this differential diagnosis. WT1 may be useful in separating Wilms' tumor from MA and papillary RCC but is not helpful in differentiating MA from papillary RCC.

Giant vascular eccrine spiradenoma: report of a case with immunohistochemical study

We report a rare case of giant vascular eccrine spiradenoma (GVES) which developed in 56-yr-old Korean woman. It is a rare variant of eccrine spiradenoma (ES), which might be mistaken for angiomatous lesions in view of its florid vascularity and hemorrhagic features. Histogenesis of GVES is not clearly elucidated although it is known that ES presumably originates in the eccrine glands. To clarify the histogenesis of GVES, immunohistochemical stainings using various monoclonal antibodies were also performed. The tumor was composed of three types of cells, namely pale epithelial cells, small basal cells, and myoepithelial cells. Therefore, we conclude that GVES originated from eccrine gland and mainly differentiates toward secretory portion of secretory coil.

Pulmonary papillary serous adenocarcinoma with intraperitoneal and ovarian tumors: identification of primary site. A case report

Papillary serous adenocarcinoma has been recognized as a highly malignant ovarian cancer and is also not uncommonly seen in primary lung cancer. Difficulty may exist in determining the origin of the primary tumor in women with synchronous pulmonary and ovarian tumors. We present a patient who was initially diagnosed and treated as stage IV papillary serous ovarian cancer with diffuse pulmonary metastases. Only transient symptomatic improvement was achieved after standard chemotherapy for ovarian cancer, and then she died of respiratory distress during treatment. Poor tumor response to chemotherapy prompted us to reevaluate the previous bronchoscopic biopsy, and immunohistochemical studies, which were cytokeratin (CK) 7 positive, CK20 negative, and thyroid transcription factor-1 (TTF-1)-positive, provided irrefutable evidences for the diagnosis of primary lung cancer. We suggest that in dealing with coexistence of ovarian and pulmonary tumors, immunohistochemical study by using CK7, CK20, and TTF-1 may be helpful in the differentiation of the primary origin.

Genomic aberrations in mucinous tubular and spindle cell renal cell carcinomas

Mucinous tubular and spindle cell carcinoma of the kidney is a new diagnostic entity. We present the pathologic and genomic characteristics of three such low-malignant tumors. Two of the tumors were found in women aged 19 and 52 years, the third tumor was found in an 80-year-old man, and the tumor stages were pT2N0MX, pT2NXMX, and pT1NXMX, respectively. Findings by immunohistochemistry were similar but not identical for the three cases; markers for both proximal and distal parts of the nephron were expressed in each tumor, a finding that is in agreement with data from previous studies. The Ki-67-labeling index was below 5 in all three cases. Two of the tumors were predominantly hypodiploid (DNA-indexes 0.77 and 0.80), whereas the third tumor was hypertriploid (1.57) as measured by DNA-image cytometry. From the latter tumor live cells were available making it possible to establish its karyotype: 62-70,XXX,+del(X)(q11),-1,+2,+4,-5,-6,+7,-8,-9,-10,-11,+12,-13,-14,-15,+16,+17,+18,-19,+20,+21,-22[cp15]. Interphase fluorescence in situ hybridization analyses with centromere-specific probes for chromosomes 1, 3, 4, 6, 7, 9, 10, 17, 18, 20, and X showed that the two hypodiploid tumors had disomic and monosomic chromosome populations, whereas the karyotyped, near-triploid tumor was dominated by trisomic chromosome populations. Comparative genomic hybridization analysis was normal for the karyotyped tumor but abnormal for the two others. We conclude that multiple numerical chromosome aberrations may be a feature of mucinous tubular and spindle cell carcinomas of the kidney, but beyond that no clear-cut karyotypic aberration pattern is so far discernible.

Stellate transformation of invasive trophoblast: a distinct phenotype of trophoblast that is involved in decidual vascular remodelling and controlled invasion during pregnancy

BACKGROUND

Successful implantation relies on the tightly regulated invasion of extravillous trophoblasts (EVTs). However, little is known about their phenotypic differentiation and relevant motile behaviour. Furthermore, the cell-cell interactions between EVTs and decidual arterioles during physiological transformation are also poorly understood.

METHODS

A total of 128 decidual specimens from early and late gestations containing components of EVTs and spiral arterioles were investigated using immunohistochemistry and periodic acid-Schiff reaction.

RESULTS

Unipolar, tadpole-like EVTs are observed throughout the interstitial area, with a tendency to decrease along the invasive pathway. The stellate differentiation of the EVTs is identified around and inside decidual arterioles or in the third-trimester myometrium. Furthermore, stellate transformation of EVTs precedes its interactions with the decidual arteriole. These specialized stellate trophoblasts invade and infiltrate the tunica media, accompanying lacuna formation inside the vessel wall and perturbation of actin fibre alignment of the tunica media.

CONCLUSION

Stellate transformation of trophoblasts may explain controlled invasion of EVTs and probably plays a key role in initiating cell-cell interaction in decidual vascular remodelling.

Diagnostic significance of aquaporin-1 in liver tumors

The diagnostic utility of aquaporin (AQP)-1 in liver tumors was tested and compared with other well-established markers. In 30 cholangiocarcinomas (CCs), 20 hepatocellular carcinomas (HCCs), and 10 metastatic colorectal carcinomas (MCCs) of the liver, expression of AQP-1, CD10, cytokeratin (CK) 7, CK20, and polyclonal carcinoembryonic antigen (pCEA) was tested. In addition, staining patterns of CD10 and pCEA were analyzed. To compare the selectivity of AQP-1 and CK7 as possible markers for differentiated cholangiocytes, liver biopsies of cholestatic disease were also analyzed. Aquaporin-1 expression was found in 93% of all CCs compared with 0% of HCC (P < .000001) and with 30% of MCC (P < .01). CD10 was positive in 16.7% of CC compared with 40% of HCC (P < .04) and to 20% of MCC (not significant). Cytokeratin 7 was positive in 90% of CC compared with 10% of HCC (P < .00001) and with 20% of MCC (P < .0001). Cytokeratin 20 was positive in 90% of MCC compared with 16.7% of CC (P < .0001) and with 20% of HCC (P < .00001). Canalicular staining patterns of CD10 and pCEA were observed in HCC (100% and 89.5%, respectively) but typically not in CC (0% and 6.7%, respectively) and never in MCC. In cholestatic disease, AQP-1 was expressed in differentiated epithelial cells of the bile ducts, whereas CK7-positive hepatocytes of Rappaport zone 1 did not show any AQP-1 reactivity. Therefore, AQP-1 seems to be a highly selective marker for differentiated cholangiocytes and can be very helpful in the differential diagnosis of liver tumors.

Immunohistochemical analysis of peritoneal mesothelioma and primary and secondary serous carcinoma of the peritoneum: antibodies to estrogen and progesterone receptors are useful

The role of immunohistochemical markers in distinguishing peritoneal mesothelioma from primary or metastatic serous papillary carcinoma of the peritoneum was evaluated. We immunostained 20 peritoneal mesotheliomas (from 14 men and 6 women), 14 primary peritoneal carcinomas, and 14 metastatic serous ovarian carcinomas with a panel of 16 antibodies. Positive staining for calretinin was identified in 17 (85%) of 20 mesotheliomas, but all carcinomas were negative. Positive staining for Ber-EP4 was identified in 27 (96%) of 28 carcinomas and in 2 (10%) of 20 mesotheliomas. Estrogen receptors were positive in 26 (93%) of 28 carcinomas, and progesterone receptors were positive in 8 (29%) of 28 carcinomas. All mesotheliomas were negative for estrogen and progesterone receptors. The other antibodies evaluated were insufficiently sensitive and/or specific to be diagnostically useful. In conjunction with calretinin and Ber-EP4, estrogen and progesterone receptors are useful discriminatory markers for distinguishing peritoneal mesothelioma from primary or metastatic serous carcinoma.

Intrahepatic cholangiocarcinoma arising in cirrhotic liver frequently expressed p63-positive basal/stem-cell phenotype

In general, intrahepatic cholangiocarcinoma (ICC) is not related to liver cirrhosis. However, a few cases have been reported in which ICC was accompanied by severe liver fibrosis. Some researchers have proposed that hepatocellular and cholangiocellular (HC-CC) carcinoma, an intermediate mixed phenotype possibly arising in cirrhotic liver, might originate from hepatic precursor cells. In the liver, hepatocytes and cholangiocytes form the epithelial element, but stromal and mesenchymal elements may be produced by hepatic stem cells. Based on these aspects, not only HC-CC, but also other combinations of cellular phenotypes, would cover all the cancers with stem cell features. In this study, which aimed at determining the characteristics of the ICC phenotype, we used immunohistochemistry to examine the expression of basal/stem-cell markers, i.e., p63 in ICC with and without liver cirrhosis, as well as the expressions of cytokeratin (CK) 34 beta E12, specific for the basal-cell marker, and c-kit, specific for the stem-cell marker. Aberrant p63 was frequently expressed in ICC arising in cirrhotic liver. This result suggests that ICC cancer cells originate from hepatic precursor cells with a hidden multi-differentiation potential.