Penetrance and Pleiotropy of Polygenic Risk Scores for Schizophrenia, Bipolar Disorder, and Depression Among Adults in the US Veterans Affairs Health Care System.

Importance: Serious mental illnesses, including schizophrenia, bipolar disorder, and depression, are heritable, highly multifactorial disorders and major causes of disability worldwide. Objective: To benchmark the penetrance of current neuropsychiatric polygenic risk scores (PRSs) in the Veterans Health Administration health care system and to explore associations between PRS and broad categories of human disease via phenome-wide association studies. Design, Setting, and Participants: Extensive Veterans Health Administration's electronic health records were assessed from October 1999 to January 2021, and an embedded cohort of 9378 individuals with confirmed diagnoses of schizophrenia or bipolar 1 disorder were found. The performance of schizophrenia, bipolar disorder, and major depression PRSs were compared in participants of African or European ancestry in the Million Veteran Program (approximately 400 000 individuals), and associations between PRSs and 1650 disease categories based on ICD-9/10 billing codes were explored. Last, genomic structural equation modeling was applied to derive novel PRSs indexing common and disorder-specific genetic factors. Analysis took place from January 2021 to January 2022. Main Outcomes and Measures: Diagnoses based on in-person structured clinical interviews were compared with ICD-9/10 billing codes. PRSs were constructed using summary statistics from genome-wide association studies of schizophrenia, bipolar disorder, and major depression. Results: Of 707 299 enrolled study participants, 459 667 were genotyped at the time of writing; 84 806 were of broadly African ancestry (mean [SD] age, 58 [12.1] years) and 314 909 were of broadly European ancestry (mean [SD] age, 66.4 [13.5] years). Among 9378 individuals with confirmed diagnoses of schizophrenia or bipolar 1 disorder, 8962 (95.6%) were correctly identified using ICD-9/10 codes (2 or more). Among those of European ancestry, PRSs were robustly associated with having received a diagnosis of schizophrenia (odds ratio [OR], 1.81 [95% CI, 1.76-1.87]; P < 10-257) or bipolar disorder (OR, 1.42 [95% CI, 1.39-1.44]; P < 10-295). Corresponding effect sizes in participants of African ancestry were considerably smaller for schizophrenia (OR, 1.35 [95% CI, 1.29-1.42]; P < 10-38) and bipolar disorder (OR, 1.16 [95% CI, 1.11-1.12]; P < 10-10). Neuropsychiatric PRSs were associated with increased risk for a range of psychiatric and physical health problems. Conclusions and Relevance: Using diagnoses confirmed by in-person structured clinical interviews and current neuropsychiatric PRSs, the validity of an electronic health records-based phenotyping approach in US veterans was demonstrated, highlighting the potential of PRSs for disentangling biological and mediated pleiotropy.

ZBTB16: a novel sensitive and specific biomarker for yolk sac tumor.

Although the function of zinc finger and BTB domain containing 16 (ZBTB16) in spermatogenesis is well documented, expression of ZBTB16 in germ cell tumors has not yet been studied. The aim of this study was to investigate the immunohistochemical expression and diagnostic utility of ZBTB16 in germ cell tumors. A total of 67 adult germ cell tumors were studied (62 testicular germ cell tumors, 2 ovarian yolk sac tumors, 1 mediastinal yolk sac tumor, and 2 retroperitoneal metastatic yolk sac tumors). The 62 testicular primary germ cell tumors are as follows: 34 pure germ cell tumors (20 seminomas, 8 embryonal carcinomas, 2 teratomas, 1 choriocarcinoma, 1 carcinoid, and 2 spermatocytic tumors) and 28 mixed germ cell tumors (composed of 13 embryonal carcinomas, 15 yolk sac tumors, 15 teratomas, 7 seminomas, and 3 choriocarcinomas in various combinations). Thirty-five cases contained germ cell neoplasia in situ. Yolk sac tumor was consistently reactive for ZBTB16. Among the 15 testicular yolk sac tumors in mixed germ cell tumors, all displayed moderate to diffuse ZBTB16 staining. ZBTB16 reactivity was present regardless of the histologic patterns of yolk sac tumor and ZBTB16 was able to pick up small foci of yolk sac tumor intermixed/embedded in other germ cell tumor subtype elements. Diffuse ZBTB16 immunoreactivity was also observed in 2/2 metastatic yolk sac tumors, 1/1 mediastinal yolk sac tumor, 2/2 ovarian yolk sac tumors, 2/2 spermatocytic tumors, 1/1 carcinoid, and the spermatogonial cells. All the other non-yolk sac germ cell tumors were nonreactive, including seminoma (n=27), embryonal carcinoma (n=21), teratoma (n=17), choriocarcinoma (n=4), and germ cell neoplasia in situ (n=35). The sensitivity and specificity of ZBTB16 in detecting yolk sac tumor among the germ cell tumors was 100% (20/20) and 96% (66/69), respectively. In conclusion, ZBTB16 is a highly sensitive and specific marker for yolk sac tumor.

Down-regulation of cytoplasmic PLZF correlates with high tumor grade and tumor aggression in non-small cell lung carcinoma.

There are currently no effective prognostic biomarkers for lung cancer. Promyelocytic leukemia zinc finger (PLZF), a transcriptional repressor, has a role in cell cycle progression and tumorigenicity in various cancers. The expression and value of PLZF in lung carcinoma, particularly in the subclass of non-small cell lung carcinoma (NSCLC), has not been studied. Our aim was to study the immunohistochemical expression of PLZF in lung adenocarcinoma and squamous cell carcinoma and correlate the alteration of PLZF expression with tumor differentiation, lymph node metastasis, tumor stage, and overall survival. A total of 296 NSCLCs being mounted on tissue microarray (181 adenocarcinomas and 91 squamous cell carcinomas) were investigated. Moderate to strong expression of PLZF was found in the cytoplasm of all the nonneoplastic respiratory epithelium and most (89.9%) well-differentiated adenocarcinoma. The proportions of moderately differentiated, poorly differentiated adenocarcinoma, and paired lymph node adenocarcinoma metastases that demonstrated negative or only weak PLZF reactivity were 75.6%, 97.2%, and 89.9%, respectively. The expression of PLZF in squamous cell carcinoma was mostly weak or absent and significantly lower than that in adenocarcinoma of the same grade (P < .0005). The loss of cytoplasmic PLZF strongly correlated with high tumor grade and lymph node metastasis in both squamous carcinoma and adenocarcinoma (P < .0001). Down-regulation of PLZF also correlated with higher tumor stage and shorter overall survival (P < .05). These results support a prognostic value for loss of cytoplasmic PLZF expression in the stratification of NSCLC and a possible role of cytoplasmic shift and down-regulation of PLZF in the pathogenesis of NSCLC.

Histone H1.5, a novel prostatic cancer marker: an immunohistochemical study.

Histone H1.5 (HH1.5) is a somatic subtype of the histone H1 family of linker proteins that are located in the nucleus and play a role in stabilizing higher-order chromatin structure, gene expression, DNA repair, and cell proliferation. Recently, differential immunohistochemical expression of HH1.5 has been found in various neuroendocrine neoplasms. This study aimed to investigate the immunohistochemical expression of HH1.5 in prostatic adenocarcinomas. Sixty-three prostate needle core biopsies, 9 radical prostatectomy specimens, and 3 metastatic prostate cancer cases were evaluated. HH1.5 immunohistochemistry revealed strong nuclear reactivity in 68 (93%) of 73 cases of prostate adenocarcinomas, compared to only 7 (9%) of 75 cases of benign prostatic glands (P ≤ .0001). In all positive benign prostate epithelium, HH1.5 was limited to focal and weak reactivity. Similarly, all 23 foci of high-grade prostatic intraepithelial neoplasia exhibited focal staining, with the vast majority having only weak nuclear reactivity. Increased HH1.5 reactivity was observed in Gleason patterns 4 and 5 as compared to Gleason pattern 3, 72% and 56%, respectively (P ≤ .02). All 3 metastatic prostate cancer cases showed strong nuclear reactivity. HH1.5 may be a useful diagnostic tool in evaluating prostatic biopsies, particularly with small foci of cancer. Further studies are needed to support these findings and investigate the possible prognostic significance of HH1.5 in prostatic adenocarcinomas.

Expression of H1.5 and PLZF in granulosa cell tumors and normal ovarian tissues: a short report.

PURPOSE: Ovarian granulosa cell tumors (GCTs) typically exhibit an excellent prognosis, but their recurrences are associated with high mortality rates. In the past, immunohistochemistry (IHC)-based approaches have been used to facilitate the distinction between GCTs and other, more frequently occurring, primary or metastatic tumors. The purpose of this study was to assess the added value of H1.5 and PLZF protein expression in the correct delineation of GCTs. METHODS: Consecutive 5-µm thick sections from routinely fixed and paraffin embedded tissues from 30 GCTs and 33 benign ovaries were processed for IHC using anti-PLZF and anti-H1.5 monoclonal antibodies. The respective protein staining intensities and distributions were quantified into reported scores for all tissue samples. Student's t-test and Fisher's exact test were used to compare the mean scores for each group. A p-value of <0.05 was considered statistically significant. Also, both the sensitivity and the specificity of the two antibodies were evaluated. RESULTS: A statistically significant difference in the expression of H1.5 between the GCT and normal ovary groups was observed (p < 0.0001). Normal ovarian tissues were found to strongly express H1.5, whereas GCTs were found to weakly express this protein. In contrast, PLZ expression was not found to be significantly different between both study groups. CONCLUSIONS: From our results we conclude that H1.5 is down-regulated in GCTs compared to normal ovarian tissues. Additional investigations on larger and more heterogeneous study populations, and on the molecular mechanism (s) underlying down-regulation of the H1.5 protein, may further substantiate the use of H1.5 as a diagnostic/prognostic marker and, in addition, provide insight into the pathogenesis of GCTs.

Immunohistochemical detection of promyelocytic leukemia zinc finger and histone 1.5 in uterine leiomyosarcoma and leiomyoma.

OBJECTIVES: The accurate distinction of leiomyoma from leiomyosarcoma is essential for patient management. However, the distinction can be difficult to make, particularly in tissue biopsy samples. Immunohistochemistry has been established as a useful technique to aid in the diagnosis of malignancies. The advantages of immunohistochemical studies are their ease of use and interpretation. This study is the first to evaluate the utility of the promyelocytic leukemia zinc finger (PLZF) protein and the histone 1.5 (H1.5) protein as potential diagnostic immunohistochemical markers for distinguishing leiomyosarcoma from leiomyoma. METHODS: Tissue samples from 21 leiomyosarcomas and 26 leiomyomas were studied. The student t-test and the Fisher exact test were used to calculate the differences in staining between the 2 groups. RESULTS: Statistically significant differences were found in the staining indices of anti-PLZF and anti-H1.5 when comparing benign and malignant tumors (P < .0001 and P < .0001, respectively). The mean H1.5 staining score in leiomyosarcomas was 158.3, compared to 28.3 in leiomyomas. The mean PLZF score in leiomyosarcomas was 1.5 in contrast to 71.5 in leiomyomas. For H1.5 at a score ≥60, the sensitivity and specificity were 90.5% and 84.6%, respectively. For PLZF, a score ≤15 had a test sensitivity and specificity of 100% and 80.8%, respectively. This suggests that staining for H1.5 or PLZF can serve as a good screening test. Additionally, combining the 2 immunostains results in a sensitivity and specificity of 90.5% and 97.5%, respectively, in differentiating between leiomyoma and leiomyosarcoma. CONCLUSIONS: We describe immunostaining for PLZF and H1.5 in benign and malignant uterine smooth muscle tumors. Statistically significant differences in staining patterns were found, suggesting utility in distinguishing leiomyosarcomas from leiomyomas.

Promyelocytic leukemia zinc finger and histone H1.5 differentially stain low- and high-grade pulmonary neuroendocrine tumors: a pilot immunohistochemical study.

Promyelocytic leukemia zinc finger is a zinc finger transcription factor that functions as a transcriptional repressor. Its expression has been shown to be down-regulated in hematopoietic, melanocytic, and mesothelial malignancies. Histone H1.5 is a variant of histone H1, a family of linker proteins that organizes chromosomes into higher order structures. Its function is of key importance in gene expression and has been linked to more aggressive forms of prostatic carcinoma. This study aimed to investigate the immunohistochemical detectability of promyelocytic leukemia zinc finger and histone H1.5 in pulmonary neuroendocrine tumors, comprising 11 carcinoid tumorlets, 24 typical carcinoids, 12 atypical carcinoids, 20 small cell carcinomas, 11 large cell neuroendocrine carcinomas, and 2 combined small cell carcinomas-large cell neuroendocrine carcinomas. Promyelocytic leukemia zinc finger immunohistochemistry revealed moderate or strong nuclear staining in all carcinoid tumorlets, 23 of 24 typical carcinoids, and 7 of 12 atypical carcinoids in contrast to 9 of 11 large cell neuroendocrine carcinomas, all small cell carcinoma, and both combined small cell carcinoma-large cell neuroendocrine carcinomas, which showed no nuclear immunoreactivity. Histone H1.5 immunohistochemistry revealed only focal or no immunoreactivity in all carcinoid tumorlets and 19 of 24 typical carcinoids, whereas 7 of 12 atypical carcinoids, 19 of 20 small cell carcinomas, 10 of 11 large cell neuroendocrine carcinomas, and both combined small cell carcinomas-large cell neuroendocrine carcinomas displayed positive (≥ 10%) nuclear immunoreactivity-ranging from a minority of weak staining to a majority of strong staining cases. Our data suggest that the relative expression ratios of promyelocytic leukemia zinc finger and histone H1.5 may correlate with grade of pulmonary neuroendocrine tumors. Immunohistochemical stains for these markers, especially on small biopsies with crush artifact, may prove to be diagnostically useful.

Evaluation of a scoring system for predicting lymph node malignancy in ultrasound guided fine needle aspiration practice.

Ultrasound-guided fine needle aspiration (USG-FNA) has enabled cytopathologists to accurately diagnose smaller or non-palpable lymph nodes (LN) on a regular basis. Pre-FNA clinical and ultrasonographic factors, such as a patient's age, ratio of short to long axis diameter (S/L ratio), internal echogenicity, and the vascular pattern of a LN, are reported to be able to predict the benign or malignant nature of a LN. This study is designed to test the formula "0.06 × (age) + 4.76 × (S/L ratio) + 2.15 × (internal echo) + 1.80 × (vascular pattern)" generated from the study of Liao et al. as a scoring system for predicting LN malignancy in a cytopathologist operated USG-FNA practice. Eighty-three reports of USG-FNA of LNs issued between 7/1/2008 and 4/28/2010 were reviewed. Patient's age, S/L ratio, internal echo, and vascular pattern were used to generate scores based on the aforementioned formula. A score of seven was used as a cutoff for predicting benign (<7) and malignant (>7) LNs. FNA cytology diagnosis, flow cytometric analysis as well as subsequent surgical diagnosis in some cases served as gold standard for statistical analysis. Among 46 USG-FNA of LNs with scores > 7, 38 were malignant and eight were benign. All 37 USG-FNA of LNs with scores < 7 were proven to be benign. The scoring system achieved 100% sensitivity, 82% specificity, 83% positive predictive value, 100% negative predictive value, and 90% accuracy. Further study of the eight "false-positive" cases revealed that three of them (37.5%) were found to be malignant in follow-up FNA and/or surgical biopsy. This scoring system may serve as a complementary tool in determining how aggressive a FNA procedure should be performed, how a FNA sample of LN should be triaged for ancillary study, and how closely a patient with lymphadenopathy should be followed up.

Anti-glutamate receptor 2 as a new potential diagnostic probe for prostatic adenocarcinoma: a pilot immunohistochemical study.

Diagnoses of prostatic carcinoma (PC) have increased with widespread screening. While the use of α-methylacyl coA racemase and high molecular weight cytokeratins have aided in distinguishing benign mimics from malignancy, their sensitivity and specificity are limited. We studied 6C4, a monoclonal antibody to glutamate receptor 2, an excitatory amino acid receptor subunit distributed throughout the central nervous system, on benign prostatic epithelium, high-grade prostatic intraepithelial neoplasia, and PC. Ten cases with post-atrophic or adenosis-like prostate glands were also stained with prostatic intraepithelial neoplasia 4, an immunostain cocktail against α-methylacyl coA racemase, p63, and high molecular weight cytokeratin, in parallel with 6C4. Immunoreactivity for 6C4 was graded as negative (0% to 10%), +1 (11%% to 50%), and +2 (>50%). Malignant epithelium was classified by Gleason patterns. Gleason patterns 4 and 5 were subdivided into cribriform or noncribriform type. Its utility in distinguishing postatrophic or adenosis-like glands from prostate cancer, both of which show absence of basal cells on prostatic intraepithelial neoplasia 4 immunostain, was also investigated. Our results revealed a statistically significant difference in staining of benign secretory prostatic epithelium, high-grade prostatic intraepithelial neoplasia, and low Gleason pattern carcinomas. The results also showed 6C4 is a sensitive marker in separating basal cell negative postatrophic or adenosis-like glands from prostate carcinoma. In addition, there was a statistically significant difference between staining of cribriform versus noncribriform Gleason pattern 4 and 5 carcinomas. A limited number of lymph node metastases from cribriform and noncribriform carcinomas were studied, and they stained the same as the primary tumor in the majority of cases. In conclusion, our preliminary data demonstrated potential utility of 6C4 in the pathologic evaluation of PC.

Thymomas diagnosed during pregnancy: two cases in young women without paraneoplastic or autoimmune disease.

We report 2 cases of thymomas diagnosed during pregnancy. Neither of these 2 patients had paraneoplastic autoimmune conditions or previous neoplasia. The first patient had a 7.3-cm lymphocyte-predominant thymoma with capsular invasion. The second patient was diagnosed through fine needle aspiration biopsy after computed tomography showed multiple mediastinal masses. Although cases of thymoma during pregnancy have been reported, the exact cause has yet to be elucidated. We review the clinical, radiologic, pathologic, and immunohistochemical findings-including those of podoplanin, estrogen receptor, and progesterone receptor-of 2 previously unreported cases, as well as discuss the relationship of malignancy and pregnancy and review the available literature regarding pregnancy and thymoma.

Papanicolaou stain may not be necessary in majority of head and neck fine-needle aspirations: evidence from a correlation study between Diff-Quik-based onsite diagnosis and final diagnosis in 287 head and neck fine-needle aspirations.

Fine-needle aspiration (FNA) is a useful tool for immediate assessment of palpable lesions, especially in the head and neck region. The objective of this study is to evaluate the degree of correlation between Diff-Quik-based onsite diagnosis (OD) and final diagnosis (FD) and further improve the efficiency of FNA practice. Two hundred and eighty-seven cytopathologist-performed FNAs from the head and neck region were evaluated. Number of passes, number and type of slides and correlation (agreement, modified final diagnosis and disagreement) between OD and FD were evaluated. Among 287 FNAs, the average number of passes per FNA case was 2 (range, 1-5&.rpar;). The mean number of slides reviewed per case was 5 including 2 Diff-Quik (D-Q)-stained slides, 2 Papanicolaou (Pap)-stained slides, and 1 cell block (CB)/1 cytospin (Cy). 247 of 287 (86%) cases showed agreement between OD and FD. FD on 36 out of 287 cases (12.5%) was slightly modified or refined after reviewing additional slides. A major diagnostic discrepancy was noted in four cases (1.5%), three of which were classified as squamous cell carcinoma on final diagnosis, and confirmed on surgical follow-up. Accurate diagnosis can be achieved in the majority (86%) of head and neck FNAs based on immediate examination of D-Q stained slides alone. In a small number of cases (12.5%), reviewing additional slides may refine the final diagnosis. In rare cases, especially cystic squamous lesions, Pap-stained slides appeared to be helpful. It is plausible to use D-Q-stained slides alone with most head and neck FNAs in order to provide more cost effective and efficient triaging and patient management.

Evaluation of apoptosis in cytologic specimens.

A hallmark of neoplasia is dysregulated apoptosis, programmed cell death. Apoptosis is crucial for normal tissue homeostasis. Dysregulation of apoptotic pathways leads to reduced cytocidal responses to chemotherapeutic drugs or radiation and is a frequent contributor to therapeutic resistance in cancer. The literature pertaining to detection of apoptotic pathway constituents in cytologic specimens is reviewed herein. Virtually all methods for detecting apoptosis, including classic cytomorphologic evaluation, TUNEL assay, immunocytochemistry, and gene sequence analysis, may be applied to cytologic samples as well as tissue. Components of both intrinsic and extrinsic apoptotic pathways have been studied, including many reports examining p53 and bcl-2, as well as studies of caspase inhibitory proteins XIAP and survivin, death receptors and ligands such as Fas, Fas-ligand, and TRAIL. p53 undergoes oncogenic alteration more than any other protein; its immunocytochemical detection almost always connotes loss of its physiologic role as an inducer of apoptosis in response to a damaged genome. Several reports establish cytologic sampling as being as useful as tissue sampling. In one respect cytologic sampling is superior to tissue sampling in particular, by allowing clinicians to repeat sampling of the same tumor before and after administration of therapy; a number of reports use this approach to attempt to predict tumor response by assaying the effect of chemotherapy on the induction of apoptosis.

p63 Immunohistochemistry is a useful adjunct in distinguishing sclerosing cutaneous tumors.

Cutaneous sclerosing epithelial neoplasms are often difficult to diagnose. Though various immunohistochemical markers have proved useful, some cases remain a diagnostic challenge. We aimed to assess the utility of p63 immunohistochemical staining in distinguishing microcystic adnexal carcinoma (MAC) from sclerosing basal cell carcinoma (SBCC) and desmoplastic trichoepithelioma (DTE). Biopsy samples from 20 SBCC, 10 DTE, and 5 MAC were examined after immunohistochemical staining with p63. Although all adnexal tumors examined demonstrated p63 expression, the pattern of staining was strikingly different in MAC when compared with other tumor types. MAC exhibited a scattered pattern with p63-positive cells around the periphery of tumor nests and minimal staining within the center of the tumor islands. This pattern was more pronounced at increased depth of infiltration into the dermis. A robust and consistent diffuse pattern of staining with p63 was observed in all SBCCs and DTEs. We believe this pattern reflects the multi-differentiation pathway of MAC, with eccrine/sebaceous differentiation occurring at deeper levels of the dermis. The different staining patterns of MACs compared with DTEs and SBCCs can thus serve asa useful diagnostic adjunct in difficult lesions.

Prognostic value of quantitative p63 immunostaining in adenoid cystic carcinoma of salivary gland assessed by computerized image analysis.

BACKGROUND: In a long-term retrospective immunohistochemical study of adenoid cystic carcinoma (ACC) of salivary gland, we investigated the relation of p63 immunodetection to prognosis. Although it is generally agreed that the solid pattern is the most aggressive pattern of growth, ACCs with predominantly cribriform or tubular patterns have an unpredictable clinical course, with a relatively favorable 5-year survival but a low 20-year survival. METHODS: Formalin-fixed paraffin sections from 35 cases of ACC showing a predominantly better differentiated histopathology, ie, cribriform or tubular patterns of growth, were immunostained for p63. Automated image analysis was used to quantify p63 positivity, using a modification of a previously developed algorithm. RESULTS: Patients alive for more than 10 years had a lower extent of p63 expression than those who died of disease. Kaplan-Meier analysis revealed that separation of patients with morbidity and mortality from those alive with no evidence of disease, could be achieved at a cutoff of 35% p63 positivity (P = .0031, log-rank test). Multivariate analysis using the Cox proportional hazard model revealed p63 and tumor stage to be independent predictors of survival (P = .012 and P = .0003, respectively). CONCLUSIONS: To our knowledge, the present study is the first to report prognostic significance of p63 in salivary gland ACC and the first report of a robust and well-studied immunohistochemical stain performable on routinely fixed and processed tissue with prognostic utility.

Immunohistochemical detection of p63 and XIAP in thymic hyperplasia and thymomas.

We subjected 23 formalin-fixed, paraffin-embedded tissue blocks (11 cases of thymic hyperplasia and 12 thymomas [3 encapsulated, 8 with capsular invasion, and 1 atypical]) to incubation with monoclonal anti-X-linked inhibitor of apoptosis protein (XIAP) (BD Biosciences, San Jose, CA) and monoclonal anti-p63 (4A4, Santa Cruz, Santa Cruz, CA). Granular or heterogeneous cytoplasmic XIAP staining and nuclear p63 staining were considered positive. We compared thymic hyperplasia with thymoma and capsulated thymoma with thymoma with capsular invasion or atypia. p63 was positive in virtually all thymic epithelial cells in hyperplasia and thymoma. XIAP was negative in all hyperplasia cases except one. Of 12 thymomas, 9 were XIAP+ with focal/weak to diffuse/strong positivity: 2 of 3 encapsulated and 7 of 8 thymomas with capsular invasion were XIAP+. One atypical thymoma was XIAP-. XIAP expression differed significantly between hyperplasia and thymoma (P = .0007) but not between capsulated and invasive thymomas (P = .3797). p63 is consistently positive in nonneoplastic and neoplastic thymic epithelium. XIAP expression in thymoma suggests a possible role in the pathogenesis of thymoma and may be helpful in differentiating thymic hyperplasia from thymoma, especially in small biopsy specimens. However, the level of expression does not correlate with capsular invasion or atypia.

An immunohistochemical study of XIAP expression in pleomorphic adenoma and carcinoma ex pleomorphic adenoma.

BACKGROUND: X-linked inhibitor of apoptosis protein (XIAP) is a member of the inhibitor of apoptosis proteins family of caspase inhibitors. Expression of XIAP in various neoplasms has been associated with aggressive behavior. The biological progression from pleomorphic adenoma (PA) to carcinoma ex pleomorphic adenoma (CXPA) has been poorly understood. We studied XIAP expression by immunohistochemistry in PA and CXPA. MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded representative sections of 14 cases of PA and seven cases of CXPA (four invasive and three intracapsular) were stained with anti-XIAP (# 610763; BD Biosciences, San Jose, CA, USA) following citrate-based antigen retrieval. Granular cytoplasmic staining was considered positive and intensity was assessed from weak (1+) to strong (3+). PAs were morphologically evaluated for cellularity, cytological atypia and mitotic activity. RESULTS: Of the seven PAs composed mostly of myxohyaline stroma with scattered ductal elements, two tumors showed no staining and five showed rare (<1%) 1+ positive cells. Of seven more cellular PAs, five had sheets of tumor cells comprising more than 50% of the tumor and two had sheets comprising more than 80% of the tumor (cellular PA), focal to diffuse 2+ to 3+ staining was observed. Tumor cells with strong staining often exhibited cytological atypia in the form of nuclear enlargement and contour irregularity, prominent nucleoli and eosinophilic cytoplasm. Mitotic activity was occasionally seen in cellular areas expressing XIAP. All cases of CXPA demonstrated diffuse 3+ staining in the carcinomatous component and 1+ to focally 3+ staining in cellular areas of the underlying PA. CONCLUSION: Increased expression of XIAP from PA to cellular PA to CXPA and in atypical cells within cellular areas of PA adds to our growing understanding of defective apoptotic pathways in malignant transformation in this group of salivary gland tumors and suggests an adenoma to adenocarcinoma model of progression. Further correlation with other oncogene expression may provide insight into the multiple molecular pathways that are affected in these tumors. Targeted therapy of XIAP may play a future role in the management of CXPA.

Immunohistochemical detection of XIAP and p63 in adenomatous hyperplasia, atypical adenomatous hyperplasia, bronchioloalveolar carcinoma and well-differentiated adenocarcinoma.

The critical distinction of bronchioloalveolar carcinoma (BAC), well-differentiated adenocarcinoma (WDAC) of lung, adenomatous hyperplasia (AH) and atypical adenomatous hyperplasia (AAH), is based on morphological criteria alone, and is therefore potentially subjective. We examined expression of two markers, X-linked inhibitor of apoptosis protein (XIAP), the most potent of the inhibitor of apoptosis protein (IAP) family, and p63, a marker of bronchial reserve cells (BRC) and squamous cells, in these entities. H&E slides of 37 tissue blocks from 27 patients were reviewed and classified as AH (n=7), AAH (n=8), BAC (n=9) and WDAC (n=13). Immunostaining was performed on 4 mum sections with monoclonal anti-XIAP and monoclonal anti-p63. Granular or heterogeneous cytoplasmic staining for XIAP and nuclear staining for p63 were considered positive. Neither XIAP nor p63 were detected in normal lung alveolar cells. All seven AHs were negative for XIAP and negative or focally positive for p63. All eight AAHs were positive for XIAP and displayed p63 positivity in scattered cells. All BACs displayed XIAP positivity, which ranged from focal/weak to diffuse/strong. p63 was negative in seven and focally positive in two of nine BACs. Twelve of 13 WDACs showed XIAP positivity in a similar pattern to BAC; all were negative for p63. One aberrant case diagnosed on H & E as WDAC was negative for XIAP but strongly positive for p63. Significant XIAP expression appears to be useful for distinguishing AAH from AH. Commonality of XIAP staining in AAH, BAC and WDAC supports the possibility that AAH may be a pre-malignant lesion. The rarity of p63 expression confirms previous reports and supports a nonbronchial histogenesis of these entities. In contrast, diffuse p63 staining may facilitate the identification of rare cases that may have been misclassified as alveolar in origin based on morphology but may be of BRC origin.

Immunohistochemical detection of the X-linked inhibitor of apoptosis protein (XIAP) in cervical squamous intraepithelial neoplasia and squamous carcinoma.

Premalignant and invasive squamous lesions of the uterine cervix were surveyed for the immunohistochemical detectability of the X-linked inhibitor of apoptosis protein (XIAP), believed to be the most potent of a novel group of proteins designated inhibitor of apoptosis proteins (IAPs). IAPs bind and prevent the activation of apoptosis-mediating caspases. Recent cancer biologic studies have implicated IAPs in therapeutic resistance and tumor aggressiveness. XIAP in particular is considered a highly promising target for drug discovery. Forty-four formalin-fixed and paraffin-embedded archival tissue sections were deparaffinized; subjected to citrate-based antigen retrieval; and immunostained with anti-XIAP monoclonal antibody (clone 48, BD Biosciences, San Jose, Calif) diluted 1:250, 4 degrees C x 72 hours; and developed using EnVision-Plus (Dako, Carpinteria, Calif) and diaminobenzidine as chromagen. Particulate or heterogeneous cytoplasmic staining was considered positive. Normal squamous epithelium was XIAP-positive in 7 of 34 cases (20.6%). Preinvasive intraepithelial lesions were positively stained in 54.5% of cases. Nineteen of 22 invasive squamous carcinomas were positive (86.4%). The intensity and extensiveness of XIAP immunostaining varied among individual cases, but trended upward with loss of tumor differentiation: 8 of 9 cases with strong staining were poorly differentiated carcinomas. The present study suggests the characteristic link between poor tumor differentiation and more aggressive clinical behavior could in some malignancies be based upon the concomitant induction of XIAP. Induction of XIAP appears to occur in a subset of intraepithelial lesions; in others, XIAP is detected only upon progression to invasive carcinoma. Detection of enhanced XIAP expression may also pinpoint those lesions that might benefit from pharmacologic disruption of XIAP's actions.

Current overview of the role of Akt in cancer studies via applied immunohistochemistry.

The family of AKT kinases, AKT-1, 2, and 3, collectively play a crucial role in key processes, as well as pathologic processes such as oncogenesis. The numerous AKT phosphorylation targets include proteins essential to the regulation of cell cycling, protein translation, suppression of programmed cell death, all of which, upon activation via AKT-mediated phosphorylation, promote tumor growth, survival, and aggressiveness. Activation of the AKT pathway can be immunohistochemically detected with antibodies that specifically react with phosphorylated or nonphosphorylated forms of AKT. The following review summarizes the use of phospho-AKT immunohistochemistry as a potentially valuable tool in cancer prognostication in a wide spectrum of common and uncommon malignancies, including squamous carcinoma of cervix and of head and neck; adenocarcinoma of endometrium, ovarian, breast, prostate, kidney, colon, and pancreas; carcinomas of lung and thyroid; and hematopoietic, soft tissue, and central nervous system neoplasms. To date, the findings overall suggest that the major use of p-AKT immunohistochemical staining lies in prognostication and possibly in individualization of therapy rather than in differential diagnosis.