Weak Positivity Research Articles

Changes in matrix metalloproteinases and their endogenous inhibitors during tumor progression in the uterine cervix.

To study the role of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in cervical tumorigenesis, we analyzed 70 cervical tissue specimens that included 15 low-grade squamous intraepithelial lesions (SILs), 20 high-grade SILs, 25 squamous cell carcinomas (SCCs) and 10 specimens of normal cervical tissue. The gelatinolytic activity of MMP-9 and MMP-2 was determined by zymographic analysis. The expression of MMP-9 and MMP-2 and TIMP-1 and TIMP-2 was determined by immunohistochemistry. All the samples had 72/66 kDa gelatinase activity; 92 kDa gelatinase activity was detected only in high-grade SILs and SCCs. Immunohistochemical analysis showed weak positivity for MMP-2 in normal cervical epithelium and low-grade SILs. However, high-grade SILs and SCCs showed intense cellular and stromal reactivity for MMP-2 and MMP-9. For TIMP-1 and TIMP-2, normal cervical epithelium and low-grade SILs showed intense immunostaining, >50% of high-grade SILs showed positivity, and 95% of SCCs showed intense stromal and cellular reactivity. Increase in the relative activity of these gelatinases and enhanced immunostaining for MMPs and TIMPs with tumor progression suggest that they may play a crucial role in cervical cancer progression. A significant association between stage of the lesion and expression of MMPs and TIMPs ( P<0.01) was found. Immunohistochemical studies indicate that these MMPs may be of basal cell origin in cervical tissue, although the mechanism of their upregulation is not clearly understood.

P53 as a prognostic factor in adrenocortical tumors of adults and children.

Mutations of the tumor suppressor gene p53 have been considered to be important determinants in several kinds of human cancer. Accumulation of p53 protein has been reported to correlate with more aggressive clinical behavior in some neoplasms. The role of p53 expression in adrenal cortical tumors (ACT) has not been elucidated but some studies have suggested its correlation with malignant behavior. Our objective was to determine if there is a correlation between the expression of immunoreactive p53 and the biological behavior of ACT. Fifty-seven ACT (21 from children and 36 from adults) were evaluated for p53 expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue and analyzed in terms of outcome. The p53 parameter was utilized semiquantitatively. Tumors were classified as p53 negative when no positivity was observed, or when only few cells showed weak positivity (0/1+) and scored as p53 positive when there was a diffuse and strong nuclear positivity (2+/3+). In children, p53 positivity was associated with clinically malignant ACT and p53 negativity was associated with clinically benign ACT (P = 0.026). In adults' ACT, p53 positivity had an effect on disease-free survival (P<0.001) and also correlated with Weiss score, with a cutoff = 4 (P = 0.04). p53 expression was related to the clinical behavior of ACT in both children and adults and these findings seem to support a role for p53 in ACT progression.

Is Fluorescence In Situ Hybridization Really Superior to HercepTest?

Is Fluorescence In Situ Hybridization Really Superior to HercepTest?

Chronic lymphocytic leukemia with t(14;18) and trisomy 12.

The chromosomal abnormality t(14;18) is most commonly associated with neoplasms of follicular center cell origin. However, t(14;18) also has been reported in rare cases of chronic lymphocytic leukemia (CLL). In 2215 cases of CLL studied by conventional cytogenetics in our institution, we identified 2 cases of CLL carrying t(14;18). Both patients were men, aged 52 and 71 years at the time of diagnosis. One patient presented with leukemia and the other primarily with nodal disease. In addition to t(14;18), trisomy 12 (+12) was identified in the same clone in both cases. Atypical morphologic features were identified: case 1 contained more than 15% lymphoid cells with cleaved nuclei, whereas case 2 contained more than 15% plasmacytoid lymphoid cells. The immunophenotype of case 2 was also unusual for CLL, showing weak CD23 expression and FMC7 positivity. We identified 6 other t(14;18)-carrying CLL cases in the literature; 2 had t(14;18) as the sole abnormality and 2 contained +12 as the additional abnormality. To conclude, cases of CLL carrying t(14;18) are exceedingly rare, and +12 appears to be the most common cytogenetic abnormality coexisting with t(14;18) in CLL.

Glandular patterns in a thyroid carcinoma with insular and anaplastic features: A case with possible implications for the classification of thyroid carcinomas

We describe the case of a 33-year-old woman with a thyroid carcinoma showing poorly differentiated (insular), anaplastic, and glandular features, the latter with extensive clear cell changes. Grossly, the well-circumscribed tumor nodule measured 3.6 cm in maximum dimension and was confined to the thyroid. Microscopically, the majority of the tumor was composed of well-defined "insular" nests showing microfollicular formation, high mitotic activity, and areas of necrosis. Other regions, as well as the intervening stroma of the insular nests, were characterized by highly atypical and pleomorphic stromal cells, extensive necrosis, and malignant cartilaginous nodules. Approximately 30% of the tumor was composed of diffuse glandular formations, each of which were lined by elongated, simple columnar cells with basally situated, mildly pleomorphic nuclei, clear supranuclear, periodic acid-Schiff + (and diastase sensitive) cytoplasm, empty lumens, and no myoepithelia or basement membranes. Immunohistochemically, the glandular elements displayed diffuse and strong positivity for thyroid transcription factor-1, bcl-2, and CAM 5.2, sparse positivity for thyroglobulin and Ki67, and diffuse but weak positivity for p53. Calcitonin was negative throughout the tumor. Karyotypic analysis of a primary culture showed a complex hypertriploid karyotype including structural abnormalities of chromosomes X, 1, 4, 6, 9, 13, and 14 in the majority of cells examined. This composite of histologic findings, especially the glandular patterns, is unusual and their prognostic significance is unclear. The patient is alive with no evidence of tumor recurrence or metastasis at 5 months follow-up. Overall, the morphologic and immunohistochemical properties of the glandular component suggests that they are less differentiated than well-differentiated carcinomas and are probably more differentiated than the insular component. This case supports the theory that the various primary carcinomas of the thyroid may represent points along a spectrum rather than distinct entities.

Diagnostic Tests for Antiribosomal P Protein Antibodies: A Comparative Evaluation of Immunoblotting and ELISA Assays

We compared the clinical sensitivity and specificity of three different methods for the detection of serum antiribosomal P protein (anti-P) antibodies in systemic lupus erythematosus (SLE).Sera from 60 unselected SLE patients, 100 healthy subjects and 100 patients with other rheumatic inflammatory diseases were screened for anti-P antibodies by immunoblotting (IB) on P proteins from Raji cells and by two ELISA assays, one using the C-terminal 22 aminoacid long synthetic peptide (C-22) of P proteins, the other using a multiple antigen peptide (MAP) carrying four copies of the C-terminal 13 aminoacid long P peptide.Anti-P antibodies were found in 20% lupus sera by IB, 16.7% by MAP ELISA and 11.7% by C-22 ELISA. The specificity for SLE diagnosis of the three tests in healthy subjects and other rheumatic diseases was: 100% by IB, 100% (vs healthy subjects) and 97% (vs rheumatic diseases) by C-22 ELISA, 100% by MAP ELISA. The agreement between methods was good; differences in concordance rates were restricted to weak positivities. We observed a high concordance in the results of IB and ELISA methods for anti-P antibody detection. IB on P proteins extracted from human lymphoid cells is more sensitive than both ELISAs; IB and MAP ELISA perform better than the C-22 ELISA in determining weakly positive sera.

Étude des anticorps anti-cytoplasme des polynucléaires neutrophiles (ANCA) dans la sclérodermie. Premier cas avec anti-protéinase 3 et revue de la littérature

Objective . To evaluate the incidence, the subspecificities and the clinical correlation of antineutrophil cytoplasmic antibodies in scleroderma patients. Methods. Sixty-two patients affected by scleroderma in limited or diffuse pattern have been screened for the presence of anti-proteinase 3 and anti-myeloperoxidase antibodies by ELISA method. Results. Two patients affected by diffuse systemic sclerosis were found to be antineutrophil cytoplasmic antibody-positive. One patient presented a weak positivity for anti-myeloperoxidase antibodies in the absence of renal impairment. One patient which clinical course is characterised by rapidly progressive skin and lung involvement presented a high positivity for anti-proteinase 3 antibody. Conclusion. Our study confirms the low incidence of antineutrophil cytoplasmic antibodies in scleroderma patients (3.2%); we report the first case of isolated scleroderma with positivity of anti-proteinase 3 antibodies.

Antineutrophil cytoplasmic antibodies in scleroderma patients: first report of a case with anti-proteinase 3 antibodies and review of the literature

Objective. To evaluate the incidence, the subspecificities and the clinical correlation of antineutrophil cytoplasmic antibodies in scleroderma patients. Methods. Sixty-two patients affected by scleroderma in limited or diffuse pattern have been screened for the presence of anti-proteinase 3 and anti-myeloperoxidase antibodies by ELISA method. Results. Two patients affected by diffuse systemic sclerosis were found to be antineutrophil cytoplasmic antibody-positive. One patient presented a weak positivity for anti-myeloperoxidase antibodies in the absence of renal impairment. One patient which clinical course is characterised by rapidly progressive skin and lung involvement presented a high positivity for anti-proteinase 3 antibody. Conclusion. Our study confirms the low incidence of antineutrophil cytoplasmic antibodies in scleroderma patients (3.2%); we report the first case of isolated scleroderma with positivity of anti-proteinase 3 antibodies.

HER2 Testing in Patients With Breast Cancer: Poor Correlation Between Weak Positivity by Immunohistochemistry and Gene Amplification by Fluorescence In Situ Hybridization

Objective To evaluate amplification of the HER-2/neu gene by fluorescence in situ hybridization (FISH) in tumors with weakly positive (2+) immunohistochemical staining. Methods A total of 1556 breast tumor biopsy specimens were referred to Mayo Medical Laboratories, Rochester, Minn, for HER2 testing between August and December 2000. Immunohistochemical (IHC) analysis was performed with use of a diagnostic test for the assessment of HER2 overexpression, the HercepTest. The IHCstained slides were interpreted and scored on a scale ranging from 0 to 3+ according to Food and Drug Administration-approved guidelines. All specimens scored as 2+ were also routinely evaluated by FISH with use of a HER-2/neu DNA probe kit (PathVysion). Specimens were determined to be amplified if the ratio of HER-2/neu signals to chromosome 17 centromere (CEP17) signals was higher than 2.0. Results Thirty-eight percent of the specimens evaluated with the HercepTest were scored 0, 35% were 1+, 14% were 2+, and 13% were 3+. Of the 216 tumor specimens scored as 2+, 26 (12%) had a high level of HER-2/neu gene amplification, 54 (25%) demonstrated duplication of HER2, 4 (2%) deleted HER-2/neu and/or CEP17, and 123 (57%) had no apparent HER-2/neu anomaly, no apparent CEP17 anomaly, nor apparent single gain (aneusomy) of CEP17. Conclusion We recommend that all specimens with a 2+ HercepTest result be evaluated by FISH for HER-2/neu gene amplification. The results of both assays should be considered before making a decision to recommend antiHER2 therapy. To evaluate amplification of the HER-2/neu gene by fluorescence in situ hybridization (FISH) in tumors with weakly positive (2+) immunohistochemical staining. A total of 1556 breast tumor biopsy specimens were referred to Mayo Medical Laboratories, Rochester, Minn, for HER2 testing between August and December 2000. Immunohistochemical (IHC) analysis was performed with use of a diagnostic test for the assessment of HER2 overexpression, the HercepTest. The IHCstained slides were interpreted and scored on a scale ranging from 0 to 3+ according to Food and Drug Administration-approved guidelines. All specimens scored as 2+ were also routinely evaluated by FISH with use of a HER-2/neu DNA probe kit (PathVysion). Specimens were determined to be amplified if the ratio of HER-2/neu signals to chromosome 17 centromere (CEP17) signals was higher than 2.0. Thirty-eight percent of the specimens evaluated with the HercepTest were scored 0, 35% were 1+, 14% were 2+, and 13% were 3+. Of the 216 tumor specimens scored as 2+, 26 (12%) had a high level of HER-2/neu gene amplification, 54 (25%) demonstrated duplication of HER2, 4 (2%) deleted HER-2/neu and/or CEP17, and 123 (57%) had no apparent HER-2/neu anomaly, no apparent CEP17 anomaly, nor apparent single gain (aneusomy) of CEP17. We recommend that all specimens with a 2+ HercepTest result be evaluated by FISH for HER-2/neu gene amplification. The results of both assays should be considered before making a decision to recommend antiHER2 therapy.

HER2 Testing in Patients With Breast Cancer: Poor Correlation Between Weak Positivity by Immunohistochemistry and Gene Amplification by Fluorescence In Situ Hybridization

To evaluate amplification of the HER-2/neu gene by fluorescence ir situ hybridization (FISH) in tumors with weakly positive (2+) immunohistochemical staining. A total of 1556 breast tumor biopsy specimens were referred to Mayo Medical Laboratories, Rochester, Minn, for HER2 testing between August and December 2000. Immunohistochemical (IHC) analysis was performed with use of a diagnostic test for the assessment of HER2 overexpression, the HercepTest. The IHC-stained slides were interpreted and scored on a scale ranging from 0 to 3+ according to Food and Drug Administration-approved guidelines. All specimens scored as 2+ were also routinely evaluated by FISH with use of a HER-2/neu DNA probe kit (PathVysion). Specimens were determined to be amplified if the ratio of HER-2/neu signals to chromosome 17 centromere (CEP17) signals was higher than 2.0. Thirty-eight percent of the specimens evaluated with the HercepTest were scored 0, 35% were 1+, 14% were 2+, and 13% were 3+. Of the 216 tumor specimens scored as 2+, 26 (12%) had a high level of HER-2/neu gene amplification, 54 (25%) demonstrated duplication of HER2, 4 (2%) deleted HER-2/neu and/or CEP17, and 123 (57%) had no apparent HER-2/neu anomaly, no apparent CEP17 anomaly, nor apparent single gain (aneusomy) of CEP17. We recommend that all specimens with a 2+ HercepTest result be evaluated by FISH for HER-2/neu gene amplification. The results of both assays should be considered before making a decision to recommend anti-HER2 therapy.

A GEOMETRIC VERSION OF DYSON'S LEMMA FOR FACTORS OF ARBITRARY DIMENSION

This paper generalizes the geometric part of the Esnault–Viehweg paper on Dyson's Lemma for a product of projective lines. Using the method of weak positivity from algebraic geometry, we are able to study products of smooth projective varieties of arbitrary dimension and to prove a geometric analogue of Dyson's Lemma for this case. Our main result is in fact a quantitative version of Faltings' product theorem.

Glomangiomyoma (glomus tumour) of the pancreas: a case report

Glomus tumours occur in many sites. We report the first case of a glomangiomyoma in the pancreas of a 17-year-old girl. The tumour was 5cm in diameter and consisted of rounded glomus cells, blood vessels and spindled smooth muscle cells. The glomus and smooth muscle tumour cells showed moderate diffuse cytoplasmic staining with vimentin, muscle-specific actin and smooth muscle actin. There was weak focal positivity for desmin in the spindle cell component only. The patient is alive and well with no evidence of recurrence 24 months after surgery.

Immunoglobulin and T-cell Receptor Gene-Gene Rearrangement in Pleural Cavity-based T-cell Rich B-cell Lymphoma in an Immunocompetent Patient

Body cavity-based lymphomas are fluid-based lymphomas that are not associated with a tumor mass or adenopathy which could explain the origin of the lymphomatous effusion. A distinct lymphoma that grows in the body cavity as a lymphomatous effusion in the absence of a tumor mass has been identified as a primary effusion lymphoma. This almost exclusively occurs in patients with acquired immunodeficiency syndrome (AIDS), who invariably have a history of Kaposi sarcoma. We report a rare case of a recurrent pleural effusion in an immunocompetent patient. There was no evidence of lymphadenopathy or an associated mass on computerized tomography of the chest, abdomen and pelvis. Serology for HIV, HHS-8, EBV and HTLV-1 were negative. Cytologic examination of the pleural fluid showed an elevated white cell count with 97% lymphocytes, mostly with T-cell markers. Bone marrow aspirate and biopsy were negative and bronchoscopy was unrevealing. Pleural biopsy was significant for >70% T-lymphocytes and some large atypical cells. Which had CD19, CD20 and weak bcl-2 positivity. Kappa and lambda light chains did not show distinct clonality. A preliminary diagnosis of T-cell rich B-cell lymphoma (TCRBCL) of the pleural cavity was made. The diagnosis was confirmed with DNA studies done on the pleural biopsy specimen using PCR and southern blot. Dual rearrangement of Ig heavy chain region and TCR-beta genes were identified. The patient responded to combination chemotherapy with cyclophosphamide, adriamycin, vincristine and prednisone. Our case is the first known case of pleural cavity-based TCRBCL and illustrates the role of gene rearrangement studies in such patients.

A panel of immunohistochemical stains, including carcinoembryonic antigen, vimentin, and estrogen receptor, aids the distinction between primary endometrial and endocervical adenocarcinomas.

The histological distinction between a primary endometrial and a primary endocervical adenocarcinoma is often difficult, especially in small biopsy specimens. A preoperative distinction is important because primary surgical management differs between the two tumors. Cases of primary endometrioid endometrial (n=30) and primary endocervical (n=26) adenocarcinoma of endocervical type were stained immunohistochemically with the monoclonal antibodies against carcinoembryonic antigen (CEA), vimentin, estrogen receptor (ER), and 34 beta E12. In all cases the origin of the adenocarcinoma was confirmed by examination of the definitive pathology specimen. There was diffuse positive nuclear staining for ER in 28 of 30 (93%) endometrial adenocarcinomas. ER was negative in 16 of 26 endocervical adenocarcinomas, and there was focal weak nuclear staining in the other cases. Vimentin was positive in 29 of 30 (97%) endometrial adenocarcinomas but in only 2 of 26 (8%) endocervical adenocarcinomas. CEA was positive in 25 of 26 (96%) endocervical adenocarcinomas, mostly with diffuse membranous and cytoplasmic staining. Positivity with CEA was present in 21 of 30 (70%) endometrial adenocarcinomas but was largely confined to squamoid areas with only 12 tumors exhibiting focal membranous staining of the glandular component. 34 beta E12 was diffusely positive in all except one cervical adenocarcinoma. In endometrial carcinomas, positivity was strongest in squamoid areas but there was positive staining, either focally or diffusely, of the glandular component in 27 cases. In summary, primary endometrioid endometrial adenocarcinomas are characterized by diffuse, strong, positive staining for vimentin and ER and negative or very focal, positive staining of the glandular component for CEA. In contrast, primary endocervical adenocarcinomas are characterized by CEA positivity, which is usually but not always diffuse, negativity for vimentin, and negativity or focal weak positivity for ER. 34 beta E12 is of no value in the distinction between endometrial and endocervical adenocarcinomas. A panel of immunohistochemical stains, comprising CEA, vimentin, and ER, generally allows confident preoperative distinction between a primary endometrial and endocervical adenocarcinoma.

Use of a panel of markers in the differential diagnosis of adenocarcinoma and reactive mesothelial cells in fluid cytology.

To evaluate the use of a panel of markers to differentiate adenocarcinoma and the reactive/inflammatory process in fluid cytology, we stained 29 formalin-fixed, paraffin-embedded cell blocks of effusion fluid from patients with metastatic adenocarcinoma and 24 cell blocks from patients with benign effusion with mucicarmine and antibodies to carcinoembryonic antigen (CEA), B72.3, and calretinin. Positive staining with CEA, B72.3, and mucicarmine was seen in 22 (76%), 20 (69%), and 18 (62%) adenocarcinoma cases, respectively. All except 1 adenocarcinoma was negative for calretinin. No benign cases were positive for B72.3 and mucicarmine. In 1 benign case, scattered epithelial cells demonstrated weak positivity for CEA. The majority of combinations were 100% specific for adenocarcinoma. The highest sensitivity (86%) for adenocarcinomas was achieved with the staining combination of negative for calretinin and positive for any adenocarcinoma marker (CEA, B72.3, or mucicarmine). The use of a panel of markers that recognize adenocarcinoma and mesothelial cells is useful in the differential diagnosis between metastatic adenocarcinoma and the reactive/inflammatory process. The profile of positive staining with at least one of the adenocarcinoma markers and negative calretinin staining is highly specific and sensitive for identifying adenocarcinoma in fluid cytology.

Immunohistochemical detection of p53 protein expression as a prognostic indicator in Wilms tumor.

Mutations of the tumor suppressor gene p53 are commonly found in several kinds of human cancer. In some types of neoplasms, accumulation of p53 protein has been reported to correlate with more aggressive clinical behavior. The role of p53 expression in Wilms tumors (WT) is not clear yet, but most studies have confirmed its correlation with anaplasia and advanced stage disease. Ninety-seven WT were evaluated for p53 expression by immunohistochemistry in formalin-fixed paraffin-embedded tissue and correlated with outcome. Tumors were classified as p53-Negative (p53-N) when no positivity was observed or only few cells showed weak positivity (0/1+) and p53-Positive (p53-P) when there was a diffuse and strong nuclear positivity (2+/3+). p53-P was detected in 13 out of 97 tumors and was associated with disease relapse (39 vs.17%; P = 0.06) but not with anaplasia. Among p53-N patients only 5% had metastatic disease compared with 31% of the p53-P sample. (P = 0.038). Overall survival was 94% for patients with p53-N vs. 85% for patients with p53-P at 1 year (P = 0.34). p53 expression in Wilms tumor detected by immunohistochemistry seems to be associated with advanced disease and relapse.

Expression of calretinin in human ovary, testis, and ovarian sex cord-stromal tumors.

Calretinin, a calcium-binding protein, is primarily expressed in certain subtypes of neurons. It has also been found to be present in mesothelial cells and mesotheliomas but not in many types of carcinomas. Using a polyclonal anti-calretinin antibody, we investigated the expression of calretinin immunohistochemically in nonneoplastic human ovaries and testes and ovarian sex cord-stromal tumors (SCSTs). In ovaries, calretinin was expressed in theca interna cells, hilus cells, and scattered individual stromal cells. Oocytes, granulosa cells, theca externa cells, rete ovarii, and most stromal cells were negative. Expression of calretinin was also seen in the ovarian surface epithelium and in collapsed and flat epithelial inclusion glands (EIGs), but not in round, columnar, and ciliated EIGs. In some glands, a transition from calretinin-positive to calretinin-negative epithelium was observed. In postpubertal testes, calretinin was expressed in Leydig cells, but not in germ cells or most rete testes and Sertoli cells. In ovarian SCSTs, strong calretinin staining was seen in all hilus cell tumors (4/4) and the Leydig cell component of Sertoli-Leydig cell tumors (10/10). The Sertoli cell component showed focal weak positivity in 5/10. Fibrothecomas were completely negative (0/8). In granulosa cell tumors, the tumor cells were either completely negative (8/14) or weakly positive at the periphery of the tumor (6/14) while scattered stromal cell staining was seen in 9/14 cases. The expression of calretinin in normal Leydig cells, theca interna cells, the Leydig cell component of Sertoli-Leydig cell tumors, and hilus cell tumors suggests its functional relationship with androgen production. Its pattern of expression in ovarian SCSTs is useful in the differential diagnosis of these tumors. The presence of a transition from calretinin-positive, flat, nonciliated epithelium to calretinin-negative, columnar, ciliated epithelium in the same glands provides strong evidence for mullerian metaplasia.

Metanephric adenoma, nephrogenic rests, and Wilms' tumor: a histologic and immunophenotypic comparison.

Metanephric adenoma (MA) is a renal tumor that is generally detected in adults and occasionally in children. These tumors usually behave in a benign fashion. Although the histogenesis of MA is unclear, a morphologic similarity to Wilms' tumor (WT) complex exists. Six cases of MA, five cases of childhood WT (CWT), two cases of adult WT (AWT), and four cases of treated MWT and/or nephrogenic rests (MWT/NR), with paraffin blocks available for use, were retrieved from the surgical pathology files of the Mayo Clinic. Clinical information was extracted from the medical record. Immunoperoxidase stains for WT1, AE1, CK7, CD57, CD56, and desmin were performed on paraffin sections from all cases. All six cases of MA were strongly and diffusely positive with antibodies to WT1 and CD57 and focally positive with antibodies to CK7. Three cases showed focal faint staining in <5% of the cells with keratin AE1. Stains for CD56 and desmin were negative. All seven cases of WT, including five CWT and two AWT, were strongly and diffusely positive with WT1 in the blastema and epithelium but showed only weak focal positivity in stromal cells. Six cases were diffusely positive for CD56 and one case showed focal positivity. Keratin AE1 was positive in one case of AWT and focally positive in the other AWT. The blastema of all cases of WT were negative for desmin, CK7, and CD57, although staining for keratin AE1, CD56, and CD57 was seen in maturing tubules of CWT cases. Of the five CWT cases, two had associated NR and two showed maturing WT after treatment. The areas of NR and maturing WT were histologically similar to MA and were composed of small tubules with uniform nuclei with no mitotic activity, scant cytoplasm, and focal calcifications. All four cases of maturing WT/NR were positive for WT1 and focally positive for CD57, CK7, and AE1. Stains for CD56 and desmin were negative except in foci of residual blastema, which stained for CD56 but lacked CD57 and CK7 staining. Five cases each of renal cell carcinoma, papillary renal cell carcinoma, and oncocytoma were negative for WT1. Two of five cases of chromophobe carcinoma showed very weak staining present in <10% of tumor nuclei. Metanephric adenoma is histogenetically related to WT and is morphologically and immunophenotypically identical to maturing WT and nephrogenic rests.

P27Kip1 Immunostaining for the Differential Diagnosis of Small B-Cell Neoplasms in Trephine Bone Marrow Biopsies

The distinction between mantle cell lymphoma (MCL) and other small B-cell non-Hodgkin lymphomas (NHL) is important because MCL has a more aggressive clinical course. In bone marrow (BM) biopsy specimens, this distinction can be particularly difficult. Although cyclin D1 immunostaining and molecular detection of the t(11;14) translocation are highly specific markers for MCL, they fail to detect a proportion of cases. We have recently described that MCL typically lacks detectable expression of the cyclin-dependent kinase inhibitor p27kip1 protein by immunostaining, which is expressed at high levels in most small B-cell NHL inversely correlated to the proliferation rate. We therefore examined whether p27kip1 immunostaining could be a useful adjunct for the differential diagnosis of small B-cell NHL infiltrates in the BM. Trephine BM biopsy specimens of 96 patients, including well-characterized MCL (19 cases), B-cell chronic lymphocytic leukemia (27 cases), follicular lymphoma (18 cases), hairy cell leukemia (22 cases), and marginal zone lymphoma (10 cases) as well as 10 reactive BM, including five with benign lymphoid aggregates were investigated. In addition, the presence of a t(11;14) translocation involving the major translocation cluster was studied by PCR in all MCL. All cases of B-cell chronic lymphocytic leukemia, follicular lymphoma, and marginal zone lymphoma revealed a strong p27kip1 nuclear staining in the majority of neoplastic cells. Fourteen (78%) cases of MCL were p27kip1-negative in the tumor cells, whereas four cases revealed a weak nuclear positivity. Seventeen (77%) cases of hairy cell leukemia were also either completely negative for p27kip1 or showed a faint positive staining in a minority of the neoplastic cells. Nine of 19 cases (47%) of MCL showed a bcl1 rearrangement involving the major translocation cluster region. These findings demonstrate that p27kip1 immunostaining is a valuable additional marker for the differential diagnosis of small B-cell NHL infiltrates in BM biopsies. The reduction or lack of p27kip1 protein expression in MCL, as well as in hairy cell leukemia, might be an important event in the pathogenesis of these disorders.

Immunoexpression of inhibin alpha-subunit in adrenal neoplasms.

Inhibin normally is produced by ovarian granulosa cells and testicular Sertoli cells. Extragonadal inhibin expression also has been detected in the placenta, pituitary gland, and liver. It may be difficult to make a distinction between adrenal cortical tumors, pheochromocytoma, and metastatic carcinomas including renal cell and hepatocellular carcinoma. Immunohistochemical expression of inhibin alpha-subunit was evaluated to determine whether any usefulness of immunostaining could be found for inhibin alpha-subunit in the differential diagnosis of adrenal glandular lesions. The authors performed immunostaining against inhibin alpha-subunit on 5 cases of normal adrenal gland, 1 case of adrenal cortical hyperplasia, 25 cases of adrenal cortical adenoma, 6 cases of adrenal cortical carcinoma, 21 cases of pheochromocytoma, 8 cases of metastatic carcinoma, and 10 cases of primary renal cell carcinoma. Normal adrenal gland showed a strong immunoreactivity against inhibin alpha-subunit, especially in the inner layer of the adrenal cortex, representing the zona reticularis, but adrenal medulla was negative for inhibin alpha-subunit. Adrenal cortical hyperplasia associated with Cushing's syndrome showed a strong, diffuse immunoreactivity for inhibin alpha-subunit. Immunoreactivity against the inhibin alpha-subunit was identified in all cases of adrenal cortical adenoma and carcinoma, especially in the adrenal cortical neoplasm with Cushing's syndrome, which showed a strong reactivity. However, immunoreactivity was absent in two metastatic carcinomas from the liver and colon and most of the pheochromocytomas, except three cases with weak focal positivity for inhibin alpha-subunit. Four cases of metastatic renal cell carcinoma and 10 cases of primary renal cell carcinoma revealed no immunoreactivity. Metastatic adenocarcinoma from the prostate showed a weak immunoreactivity for inhibin alpha-subunit. Metastatic hepatoblastoma was negative against inhibin alpha-subunit with endogenous biotin blocking. Immunoexpression for inhibin alpha-subunit is useful for making distinction between adrenal cortical tumors, pheochromocytoma, and metastatic carcinoma. Inhibin alpha-subunit may be valuable as part of a diagnostic immunohistochemical panel in adrenal glandular lesions.