Value of GATA3 immunostaining in tumor diagnosis: a review

GATA3 expression in tumor-infiltrating mononuclear inflammatory cells is associated with poor prognostic factors in tubo-ovarian carcinomas

The study investigated the expression of GATA3, a transcription factor involved in immune regulation, in tubo-ovarian carcinomas and its association with clinicopathological factors and prognosis. Immunohistochemical analysis was performed on 91 tubo-ovarian carcinoma samples to determine the presence of GATA3-positive inflammatory cells in the tumor microenvironment. A threshold of 10% or higher was considered a positive expression. The results showed that 46.7% of tubo-ovarian carcinomas exhibited positive expression of GATA3 in inflammatory cells. There was no significant difference in GATA3 expression between patients who received pre-surgical chemotherapy and those who underwent primary surgery. However, high-grade serous carcinomas had a significantly higher proportion of GATA3-positive inflammatory cells compared to other subtypes. Advanced-stage tumors (stage III) had a higher percentage of GATA3-positive inflammatory cells compared to stage II and I tumors. Patients with positive GATA3 expression had a significantly lower disease-free survival rate. However, there was no significant association between GATA3 expression and chemotherapy response score. These findings suggest that increased expression of GATA3 in mononuclear inflammatory cells is associated with higher grade, advanced stage, and increased risk of recurrence in tubo-ovarian carcinoma. This implies that heightened GATA3 expression negatively impacts anti-tumor immunity, tumor growth progression, and invasiveness in tubo-ovarian carcinomas.

Occult urothelial carcinoma with mediastinal metastasis: A case report

Occult urothelial carcinoma (UC), particularly with mediastinal metastases, is an uncommon clinical occurrence. The present study describes the unusual case of a 70-year-old male patient who developed mediastinal metastases from an occult UC. Histological evaluations and immunohistochemical features of the mediastinal tumor were indicative of UC; however, extensive imaging failed to identify the primary urological lesion. The findings suggest that mediastinal metastases from UCs, despite their rarity, should be considered in cases where patients with mediastinal tumors exhibit chest-related symptoms. Prompt pathological examinations are crucial for ascertaining the nature and origin of the tumor. Moreover, individualized treatment should be performed in strict accordance with the established oncology guidelines.

Surgery for pulmonary lesions in patients with a history of urinary tract transitional cell carcinoma

BACKGROUND

There has been little information on the actual diagnosis of pulmonary lesions in patients with a history of urinary tract transitional cell carcinoma (TCC) and short- and long- outcomes of pulmonary resection for these patients.

METHODS

In the present study, the data of 37 consecutive patients with a history of TCC who underwent pulmonary resection for solitary pulmonary lesions were reviewed, and the clinical factors and short- and long-term outcomes were analyzed.

RESULTS

The study population included 35 male patients, and 2 female patients. The mean age was 72.5 years. Twenty patients (80%) were smokers and showed a high incidence of chronic obstructive pulmonary disease. Pulmonary lesions and primary TCC were detected simultaneously in 5 patients and metachronously in 32 patients. The median interval between treatment for primary TCC and the detection of pulmonary lesion was 43 months. The mean tumor diameter was 23 mm. The types of resection included lobectomy (n = 19), segmentectomy (n = 8), and partial resection (n = 10). Twelve of 37 patients (32%) developed postoperative complications. The pathological diagnoses included primary lung cancer (n = 28), pulmonary metastasis from TCC (n = 7), and others (n = 2). The 5-year overall survival rate for all patients was 72%. The 5-year overall survival rate of patients with primary lung cancer was 74%, while that of patients with pulmonary metastasis from TCC was 57%.

CONCLUSIONS

Surgery can be proactively considered for treating pulmonary lesions in patients with a previous history of TCC, as it provides favorable long-term outcomes.

GATA3 promotes the autophagy and activation of hepatic stellate cell in hepatic fibrosis via regulating miR-370/HMGB1 pathway

BACKGROUND

Hepatic fibrosis (HF) is a common result of the repair process of various chronic liver diseases. Hepatic stellate cells (HSCs) activation is the central link in the occurrence of HF.

METHODS

ELISA and histological analysis were performed to detect the pathological changes of liver tissues. In vitro, HSCs were treated with TGF-β1 as HF cell model. Combination of GATA-binding protein 3 (GATA3) and miR-370 gene promoter was ensured by ChIP and luciferase reporter assay. Autophagy was monitored by observing the GFP-LC3 puncta formation. The interaction between miR-370 and high mobility group box 1 protein (HMGB1) was verified by luciferase reporter assay.

RESULTS

CCl4-induced HF mice exhibited an increase of ALT and AST, and severe damage and fibrosis of liver tissues. GATA3 and HMGB1 were up-regulated, and miR-370 was down-regulated in CCl4-induced HF mice and activated HSCs. GATA3 enhanced expression of the autophagy-related proteins and activation markers in the activated HSCs. Inhibition of autophagy partly reversed GATA3-induced activation of HSCs and the promotion of GATA3 to hepatic fibrosis. Moreover, GATA3 suppressed miR-370 expression via binding with its promotor, and enhanced HMGB1 expression in HSCs. Increasing of miR-370 inhibited HMGB1 expression by directly targeting its mRNA 3'-UTR. The promotion of GATA3 to TGF-β1-induced HSCs autophagy and activation was abrogated by miR-370 up-regulation or HMGB1 knockdown.

CONCLUSIONS

This work demonstrates that GATA3 promotes autophagy and activation of HSCs by regulating miR-370/HMGB1 signaling pathway, which contributes to accelerate HF. Thus, this work suggests that GATA3 may be a potential target for prevention and treatment of HF.

Trichorhinophalangeal Syndrome Type 1 Is a Highly Sensitive and Specific Marker for Diagnosing Triple-Negative Breast Carcinomas on Cytologic Samples

CONTEXT.—

Definitive diagnosis of metastatic triple-negative breast carcinoma (TNBC) is challenging on cytologic samples. Recent studies demonstrated that trichorhinophalangeal syndrome type 1 (TRPS1) is a highly sensitive and specific marker for diagnosing breast carcinomas, including TNBC, on surgical specimens.

OBJECTIVE.—

To evaluate TRPS1 expression in TNBCs on cytologic samples and a large series of nonbreast tumors on tissue microarray sections.

DESIGN.—

Immunohistochemical (IHC) analysis of TRPS1 and GATA-binding protein 3 (GATA3) was performed on 35 TNBC cases on surgical specimens, and 29 consecutive TNBC cases on cytologic specimens. IHC analysis of TRPS1 expression was also performed on 1079 nonbreast tumors on tissue microarray sections.

RESULTS.—

Of the surgical specimens, 35 of 35 TNBC cases (100%) were positive for TRPS1, all with diffuse positivity, whereas 27 of 35 (77%) were positive for GATA3, with diffuse positivity in 7 cases (26%). Of the cytologic samples, 27 of 29 TNBC cases (93%) were positive for TRPS1, with diffuse positivity in 20 cases (74%), whereas 12 of 29 (41%) were positive for GATA3, with diffuse positivity in 2 cases (17%). Of the nonbreast malignant tumors, TRPS1 expression was seen in 9.4% (3 of 32) of melanomas, 10.7% (3 of 28) of small cell carcinomas of the bladder, and 9.7% (4 of 41) of ovarian serous carcinomas.

CONCLUSIONS.—

Our data confirm that TRPS1 is a highly sensitive and specific marker for diagnosing TNBC cases on surgical specimens as reported in the literature. In addition, these data demonstrate that TRPS1 is a much more sensitive marker than GATA3 in detecting metastatic TNBC cases on cytologic samples. Therefore, inclusion of TRPS1 in the diagnostic IHC panel is recommended when a metastatic TNBC is suspected.

Diagnostic and Prognostic Roles of GATA3 Immunohistochemistry in Urothelial Carcinoma

This study aimed to evaluate the diagnostic and prognostic roles of GATA-binding protein 3 (GATA3) immunohistochemistry in urothelial carcinoma (UC) using a meta-analysis. We investigated GATA3 immunohistochemical expression rates and performed a subgroup analysis based on tumor site, study location, and histological subtypes. The overall survival rates of patients with GATA3-positive and -negative UC were compared. The estimated GATA3 expression rate was 0.748 (95% confidence interval [CI]: 0.704-0.787). GATA3 expression rates in the urinary bladder and urinary tract were 0.775 (95% CI: 0.727-0.818) and 0.614 (95% CI: 0.426-0.774), respectively. The GATA3 expression rates of noninvasive and invasive UCs were 0.965 (95% CI: 0.938-0.980) and 0.644 (95% CI: 0.581-0.702), respectively. In invasive UCs, there was a significant difference in GATA3 expression between non-muscular invasion and muscular invasion subgroups (0.937, 95% CI: 0.883-0.967 vs. 0.753, 95% CI: 0.645-0.836). GATA3 expression was the highest in the microcytic subtype among the histologic subtypes (0.952, 95% CI: 0.724-0.993). There was a significant correlation between GATA3 expression and better prognosis (hazard ratio: 0.402, 95% CI: 0.311-0.521). Taken together, GATA3 expression significantly correlated with low-stage and better prognosis in UC. GATA3 expression is highly variable across histological subtypes, and one should be careful while interpreting GATA3 expression.

Scoring Systems for Immunohistochemistry in Urothelial Carcinoma

Immunohistochemistry is widely used in diagnostic and scientific analysis of urothelial carcinoma. Objective interpretation of staining results is mandatory for accuracy and comparability in diagnostic and therapeutic patient care as well as research.Herein we summarize and explain standardized microscopic evaluation and scoring approaches for immunohistochemical stainings. We focus on commonly used and generally feasible approaches for different cellular compartments and comment on their utility in diagnostics and research practice.

Median raphe cysts: A clinico-pathologic and immunohistochemical study of 52 cases

BACKGROUND

Median raphe cysts (MRC) are epithelial-lined cystic lesions of the genital area that do not communicate with the urethra or the overlying epidermis. Immunohistochemically, MRC show positivity for cytokeratin (CK) 5-6, CK 7, carcinoembryonic antigen, p63 and uroplakin III (URO III). GATA3 and human milk fat globulin 1 (HMFG1) are immunohistochemical markers that have been not previously studied in MRC.

METHODS

We conducted a study of 52 patients diagnosed with MRC in the Pathology Departments of eight hospitals between 1990 and 2016. The monoclonal antibodies used were CK5-6, CK7, CK20, URO III, p63, GATA3, and HMFG1. HMFG1 was studied in five cases of apocrine hidrocystomas and compared with five cases of MRC from our series.

RESULTS

CK 5-6, CK7, and p63 expression showed strong positivity in the urothelial epithelium of 48 cases. CK20 was focally positive in areas of mucinous differentiation in three cases. GATA3 showed intense nuclear staining in 30 cases. HMFG1 was positive in three cases of MRC and in three cases of apocrine hidrocystoma.

CONCLUSION

Positivity of GATA3 and CK7 in MRC supports the urothelial origin of these cysts. We found no differences in HMFG1 expression between MRC and apocrine hidrocystomas.

[Three cases of urachal cyst in adults]

The urachus is a thick fibrous cord that appears in the fifth month of pregnancy as a result of the allantois obliteration. Urachal cysts occur as a result of a defect in the obliteration of the duct, anomaly detected mainly in children and very rarely in adults. We present three cases of urachal cysts in adults, one of them detected during the study of abdominal pain and the other two, found incidentally during the study of other pathologies. In any case the possibility of urachal cysts was clinically suspected. Histologically, these lesions are lined by epithelium of urothelial type with expression of CK7, CK20, CK5/6, P63 and GATA3. The diagnosis of urachal cysts certainty lies in the histopathological study where the morphology, immunohistochemistry and a proper clinical-pathological correlation, allow to differentiate it from other more frequent abdominal cystic lesions in adults.

Pancreatic metastasis of invasive ductal breast carcinoma: A potential diagnostic pitfall

The 42-year-old patient, diagnosed with Stage IIA breast cancer, completed the postoperative adjuvant chemotherapy and radiotherapy. At the 11th year of diagnosis, a 3 cm tumor was detected in the pancreas and pancreatectomy was performed. Although the diagnosis of primary pancreatic adenocarcinoma was made at first, then the pancreatic metastasis of breast cancer was discovered. Pancreatic metastasis of breast cancer is extremely rare, and a limited number of patients have been reported in the literature. Here, we report an additional case of this rare tumor and the problems correlating with its diagnosis.

Role of GATA3 in tumor diagnosis: A review

GATA binding protein 3 (GATA3) belongs to a family of transcription factors comprising six members. These proteins identify G-A-T-A containing sequences in the target gene and bind to DNA target via two zinc-finger domains. The aim of this study was to evaluate the role of GATA3 in the diagnosis of tumors and its value as a prognostic marker. To perform this review, a comprehensive search was conducted through PubMed, Embase, Scopus, Cochrane and Google Scholar databases from 1985 to 2020. Articles were considered thoroughly by independent reviewers and data were extracted in predefined forms. Final synthesis was conducted by using appropriate data from included articles in each topic. Studies have shown that GATA3 has a critical role in the development of epithelial structures in both embryonic and adult tissues. The majority of studies regarding GATA3 expression in tumor evaluation focused on breast and urothelial neoplasms, whether primary or metastatic. Its sensitivity in these neoplasms has been reported to be high and made this marker more valuable than other available immunohistochemistry markers. However, GATA3 expression was not restricted to these tumors. Studies have shown that GATA3 immunostaining could be a useful tool in various tumors in kidney, salivary gland, endocrine system, hematopoietic system, and skin. GATA3 can also be used as a useful prognostic tool. Although GATA3 is a multi-specific immunohistochemical stain, it is a valuable marker in the panel for confirming many epithelial or mesenchymal neoplasms as both a diagnostic and prognostic tool.

Dysregulated Immunological Functionome and Dysfunctional Metabolic Pathway Recognized for the Pathogenesis of Borderline Ovarian Tumors by Integrative Polygenic Analytics

The pathogenesis and molecular mechanisms of ovarian low malignant potential (LMP) tumors or borderline ovarian tumors (BOTs) have not been fully elucidated to date. Surgery remains the cornerstone of treatment for this disease, and diagnosis is mainly made by histopathology to date. However, there is no integrated analysis investigating the tumorigenesis of BOTs with open experimental data. Therefore, we first utilized a functionome-based speculative model from the aggregated obtainable datasets to explore the expression profiling data among all BOTs and two major subtypes of BOTs, serous BOTs (SBOTs) and mucinous BOTs (MBOTs), by analyzing the functional regularity patterns and clustering the separate gene sets. We next prospected and assembled the association between these targeted biomolecular functions and their related genes. Our research found that BOTs can be accurately recognized by gene expression profiles by means of integrative polygenic analytics among all BOTs, SBOTs, and MBOTs; the results exhibited the top 41 common dysregulated biomolecular functions, which were sorted into four major categories: immune and inflammatory response-related functions, cell membrane- and transporter-related functions, cell cycle- and signaling-related functions, and cell metabolism-related functions, which were the key elements involved in its pathogenesis. In contrast to previous research, we identified 19 representative genes from the above classified categories (IL6, CCR2 for immune and inflammatory response-related functions; IFNG, ATP1B1, GAS6, and PSEN1 for cell membrane- and transporter-related functions; CTNNB1, GATA3, and IL1B for cell cycle- and signaling-related functions; and AKT1, SIRT1, IL4, PDGFB, MAPK3, SRC, TWIST1, TGFB1, ADIPOQ, and PPARGC1A for cell metabolism-related functions) that were relevant in the cause and development of BOTs. We also noticed that a dysfunctional pathway of galactose catabolism had taken place among all BOTs, SBOTs, and MBOTs from the analyzed gene set databases of canonical pathways. With the help of immunostaining, we verified significantly higher performance of interleukin 6 (IL6) and galactose-1-phosphate uridylyltransferase (GALT) among BOTs than the controls. In conclusion, a bioinformatic platform of gene-set integrative molecular functionomes and biophysiological pathways was constructed in this study to interpret the complicated pathogenic pathways of BOTs, and these important findings demonstrated the dysregulated immunological functionome and dysfunctional metabolic pathway as potential roles during the tumorigenesis of BOTs and may be helpful for the diagnosis and therapy of BOTs in the future.

Brenner tumor associated with rete ovarii: a histologic and immunohistochemical analysis of six cases exploring the relationship between these entities

The association of Brenner tumor (BT) with rete ovarii (RO) has been rarely alluded to in the literature. Both entities have debatable histogenesis. In this study of six cases of BT associated with RO, we describe the morphologic features and performed immunohistochemical staining for markers of Mullerian, Wolffian, mesothelial, and sex cord stromal derivation to explore the relationship between these entities. Histologically, all BTs were benign, microscopic, and incidental. RO was prominent and hyperplastic with gradual or abrupt transition to BT. In addition, focal areas of rete entrapped between BT nests were seen. All BTs were positive for GATA-3 and negative for PAX-8. Conversely, the RO in all cases was negative for GATA-3 and positive for PAX-8. WT-1 was positive in both entities. Sex cord stromal and mesothelial markers (other than WT-1) were negative in BT and RO. Although morphologically, BTs seem to arise from RO in these cases, they have a distinct immunophenotype. It is possible that at least some BTs arise from metaplastic changes in RO epithelium.

Aberrant GATA3 Staining in Prostatic Adenocarcinoma: A Potential Diagnostic Pitfall

Distinguishing between poorly differentiated urothelial carcinoma and high-grade prostatic adenocarcinoma is a common challenge in genitourinary pathology, particularly when the tumor involves the bladder neck or prostatic urethra. Clinically, the distinction between these 2 tumors can also be difficult. Proper diagnosis in these patients is essential as they have differing prognoses and clinical management. GATA3 is thought to be a sensitive and relatively specific marker of urothelial carcinoma. However, there is scant data regarding GATA3 labeling of high-grade prostatic adenocarcinoma. The aim of this study is to describe rare cases with strong aberrant GATA3 staining in prostatic adenocarcinoma as a potential diagnostic pitfall. We identified 9 cases of prostatic adenocarcinoma with aberrant positive GATA3 staining from 2015 to 2020 as part of a large consultation service at our institution. All 9 cases were grade group 5, 8 had a Gleason score of 5+5=10 and 1 had a score of 4+5=9. Five of the cases were from the prostate, 3 from the urinary bladder, and 1 from the prostatic urethra. All cases were morphologically typical of high-grade prostatic adenocarcinoma, although were sent for consultation due to uncertainty in the diagnosis. GATA3 positivity was strong, diffuse in 4 cases; strong, patchy in 2 cases and strong, focal in 3 cases. All cases were positive for NKX3.1, 6 positive for p501s, and 6 positive for PSA, with 7/9 cases showing expression of at least 2 prostate-specific markers. The current study describes that rare cases of prostatic adenocarcinoma can show focal or diffuse strong staining for GATA3. In order to avoid this diagnostic pitfall, undifferentiated carcinomas involving the prostate, bladder neck, or trigone should be evaluated not only with GATA3 but also prostate-specific markers.

Utility of Immunohistochemistry for MUC4 and GATA3 to Aid in the Distinction of Pleural Sarcomatoid Mesothelioma From Pulmonary Sarcomatoid Carcinoma

CONTEXT.—

Distinguishing pulmonary sarcomatoid carcinoma from pleural sarcomatoid mesothelioma is challenging because of overlapping histology, immunophenotype, and clinical features. Reliable immunohistochemical markers to aid in this distinction would be very valuable. Recent studies have proposed that MUC4 expression is common in sarcomatoid carcinoma but not in sarcomatoid mesothelioma, with the converse pattern reported for GATA3.

OBJECTIVE.—

To further explore the utility of MUC4 and GATA3 in distinguishing pulmonary sarcomatoid carcinoma from sarcomatoid mesothelioma.

DESIGN.—

Well-characterized cases of sarcomatoid carcinoma (n = 32) and sarcomatoid mesothelioma (n = 64) were included. Diagnoses were confirmed by thoracic pathologists with incorporation of immunophenotype, clinical, and radiographic features. Whole-tissue sections were stained for GATA3 and MUC4.

RESULTS.—

Patients with sarcomatoid carcinoma and sarcomatoid mesothelioma had similar mean age and male predominance. GATA3 was positive in 63 of 64 sarcomatoid mesotheliomas (98%; 42 diffuse, 16 patchy, 5 focal), and 15 of 32 sarcomatoid carcinomas (47%; 3 diffuse, 8 patchy, 4 focal). MUC4 was positive in 2 of 64 sarcomatoid mesotheliomas (3%; 1 patchy, 1 focal), and in 12 of 32 sarcomatoid carcinomas (38%; 5 diffuse, 6 patchy, 1 focal).

CONCLUSIONS.—

Diffuse GATA3 expression favors sarcomatoid mesothelioma over sarcomatoid carcinoma, which rarely shows diffuse expression (sensitivity and specificity of diffuse staining 66% and 94%, respectively). Focal and patchy GATA3 expression is observed in both tumor types, and therefore is not helpful in this distinction. Sensitivity of MUC4 for sarcomatoid carcinoma was low in our cohort, positive in only 38% with frequent patchy staining, but it was quite specific.

Clinical Applications of Immunohistochemistry in Germ Cell Tumors in Men

Germ cell tumors (GCT) in men comprise of tumor subtypes with distinct histomorphologies, genetic and genomic alterations, and clinical behavior. Immunohistochemical (IHC) markers, including many newly described nuclear transcription factors, are often applied in challenging cases to arrive at a correct diagnosis and classification, and to establish germ cell origin for metastatic tumors. However, there is no established role for IHC markers in prognosis and therapy response prediction in GCTs. This chapter briefly reviews the clinical utility of IHC in diagnosis and classification of GCTs, including technical aspects of performing IHC and clinical applications of commonly used IHC markers in the workup of common and clinically relevant diagnostic scenarios.

Incidence and significance of GATA3 positivity in gallbladder adenocarcinoma

GATA3 immunostaining is a sensitive marker for mammary and urothelial carcinomas. It is routinely used in surgical pathology during workup of carcinomas of unknown origin. To the best of our knowledge, this is the first focused study of GATA3 expression in gallbladder adenocarcinomas. In this study, we evaluated GATA3 expression in 38 gallbladder adenocarcinomas. Eight of 38 (21%) gallbladder adenocarcinomas were positive for GATA3. The expression of GATA3 tended to be moderate to strong when present. It was patchy (<50% positivity) in 4 cases, characterized by discrete clusters or groups of malignant cells with areas of intervening negative tumor cells, whereas it was diffuse (>50% positivity) in the other 4 cases. GATA3 expression did not show any significant correlation with clinicopathologic features such as sex, histologic grade, perineural invasion, vascular invasion, pathologic stage, or distance metastasis. The results of our study show that a subset of gallbladder adenocarcinomas (21%) can be GATA3 positive. Awareness of this phenomenon is important while working up GATA3-positive carcinomas immunohistochemically.

[E-Cadherine and GATA-3 are useful in the confirmation of the vas deferens in vasectomy specimens]

INTRODUCTION AND OBJECTIVES

Urologists often submit the resected tissue from vasectomies for histopathological examination in order to confirm the presence of the vas deferens. Microscopy is simple and based on haematoxylin-eosin staining; however, sample artefacts can sometimes cause confusion and immunohistochemistry can be used to identify the vas deferens.

MATERIALS AND METHODS

We investigated the utility of immunohistochemical analysis using E-cadherin and GATA-3 to confirm the presence of vas deferens epithelium in 110 vasectomy sections with different artefacts, using monoclonal antibodies and a multimer conjugated with peroxidase based technique; 5 renal arteries and 5 renal veins were stained as negative controls.

RESULTS

Membrane staining was observed for E-cadherin, which was moderate (2.7%) or strong (97.3%) in the vas deferens epithelium in all cases: 35 without artefacts, 7 with denuded epithelium, 56 with compressed/distorted epithelium, 8 with detached epithelium and 4 with displaced epithelium. GATA-3 showed moderate (31%) or strong (69%) nuclear staining in all cases, including the 76 with artefacts. In the control group, arteries and veins were negative for both markers in the endothelium, but GATA-3 occasionally stained lymphocytes in the blood vessel wall.

CONCLUSIONS

E-cadherin membrane positivity and GATA-3 nuclear expression are useful for the identification of the vas deferens in vasectomy samples containing artefacts. Vascular endothelium is negative for both markers and any possible GATA-3 staining of the lymphocytes in the blood vessel wall should not be misinterpreted.

Utility of GATA-3 Expression in the Analysis of Pituitary Neuroendocrine Tumour (PitNET) Transcription Factors

With the introduction of the WHO 2017 classification of endocrine neoplasms, the use of the pituitary transcription factors PIT-1, Tpit and SF-1 has become the standard of care. However, immunohistochemistry for these transcription factors is not available in all institutions, and their reliability has been questioned. We read with interest the findings of Mete et al. that GATA-3 expression was detected in some pituitary neuroendocrine tumours (PitNET). We therefore sort to validate this in our large cohort of PitNETs. We searched the database of Royal North Shore Hospital for PitNETs between 1998 and 2012, constructed a tissue microarray and reclassified these entities based on their expression for PIT-1, Tpit and SF-1. We then scored the expression of GATA-3 immunohistochemistry on a scale of 0-2, where 0 was no staining, 1 was patchy or weak staining and 2 was strong and diffuse staining. 265 of 346 tumours were able to be classified into a specific tumour subtype, and 263 tumours had tissue available for GATA-3 immunohistochemistry. 89% of gonadotrophs and 93% of triple-negative tumours with expression for luteinising hormone and follicle-stimulating hormone were positive for GATA-3. In the triple-negative group, GATA-3 was positive in 1 mammosomatotroph and 80% of tumours with thyroid-stimulating hormone expression. In the triple-negative hormone-negative group, 21 of 33 tumours were positive (64%). The results demonstrate that GATA-3 is a useful marker to supplement the existing pituitary transcription factors, albeit slightly less sensitive and specific than previously reported. GATA-3 may be employed in addition to the current array of immunohistochemical transcription factors, especially in the resource poor setting. However, given its potential cross-reactivity with other entities of the Sella, positive staining should be interpreted with caution and in the morphological and clinical context.

Reduced expression of GATA3 predicts progression in non-muscle invasive urothelial carcinoma of the urinary bladder

Urothelial carcinoma (UC) of the urinary bladder is the ninth most common cancer worldwide. The majority of these patients present with non-muscle invasive bladder cancer (NMIBC). GATA3 has recently emerged as one of the diagnostically helpful immunohistochemical markers for UC. The published literature, however, lacks comprehensive studies on the impact of GATA3 expression on the prognosis of UC patients. This study evaluated and statistically analyzed the immunohistochemical expressions of GATA3 and Ki67 in 50 Egyptian patients with NMIBC and correlated the markers' expressions with clinicopathological variables and patients' outcome. Ten control cases were included. The expressions of GATA3 and Ki67 were significantly downregulated and upregulated respectively in UC cases compared to the control group. GATA3 down-expression was significantly associated with high grade tumors and tumor progression with 72% prediction accuracy. Higher proliferative activity was significantly correlated with high grade, non-papillary growth pattern, and lamina propria invasion. The predictive performance of GATA3 and Ki67 in predicting malignancy and tumor grade was good. We concluded that GATA3 downregulation and increased proliferative activity might be implicated in UC tumorigenesis, loss of differentiation, and aggressiveness. Reduced GATA3 expression could predict progression in NMIBC with an accuracy of 72% and thus it constitutes a potentially promising novel prognostic marker in patients with urothelial carcinoma.

Practical Application of Lineage-Specific Immunohistochemistry Markers: Transcription Factors (Sometimes) Behaving Badly

CONTEXT.—

Transcription factors (TFs) are proteins that regulate gene expression and control RNA transcription from DNA. Lineage-specific TFs have increasingly been used by pathologists to determine tumor lineage, especially in the setting of metastatic tumors of unknown primary, among other uses. With experience gathered from its daily application and increasing pitfalls reported from immunohistochemical studies, these often-touted highly specific TFs are not as reliable as once thought.

OBJECTIVES.—

To summarize the established roles of many of the commonly used TFs in clinical practice and to discuss known and potential sources for error (eg, false-positivity from cross-reactivity, aberrant, and overlap "lineage-specific" expression) in their application and interpretation.

DATA SOURCES.—

Literature review and the authors' personal practice experience were used. Several examples selected from the University Health Network (Toronto, Ontario, Canada) are illustrated.

CONCLUSIONS.—

The application of TF diagnostic immunohistochemistry has enabled pathologists to better assess the lineage/origin of primary and metastatic tumors. However, the awareness of potential pitfalls is essential to avoid misdiagnosis.

Gene Expression Profiling for Diagnosis of Triple-Negative Breast Cancer: A Multicenter, Retrospective Cohort Study

Background: Triple-negative breast cancer (TNBC) accounts for 12–20% of all breast cancers. Diagnosis of TNBC is sometimes quite difficult based on morphological assessment and immunohistochemistry alone, particularly in the metastatic setting with no prior history of breast cancer.

Methods: Molecular profiling is a promising diagnostic approach that has the potential to provide an objective classification of metastatic tumors with unknown primary. In this study, performance of a novel 90-gene expression signature for determination of the site of tumor origin was evaluated in 115 TNBC samples. For each specimen, expression profiles of the 90 tumor-specific genes were analyzed, and similarity scores were obtained for each of the 21 tumor types on the test panel. Predicted tumor type was compared to the reference diagnosis to calculate accuracy. Furthermore, rank product analysis was performed to identify genes that were differentially expressed between TNBC and other tumor types.

Results: Analysis of the 90-gene expression signature resulted in an overall 97.4% (112/115, 95% CI: 0.92–0.99) agreement with the reference diagnosis. Among all specimens, the signature correctly classified 97.6% of TNBC from the primary site (41/42) and lymph node metastasis (41/42) and 96.8% of distant metastatic tumors (30/31). Furthermore, a list of genes, including AZGP1, KRT19, and PIGR, was identified as differentially expressed between TNBC and other tumor types, suggesting their potential use as discriminatory markers.

Conclusion: Our results demonstrate excellent performance of a 90-gene expression signature for identification of tumor origin in a cohort of both primary and metastatic TNBC samples. These findings show promise for use of this novel molecular assay to aid in differential diagnosis of TNBC, particularly in the metastatic setting.

GATA3 immunoreactivity expands the transcription factor profile of pituitary neuroendocrine tumors

The modern classification of pituitary neuroendocrine tumors relies mainly on immunohistochemistry for pituitary transcription factors, hormones, and other biomarkers, including low molecular weight cytokeratins. The transcription factor GATA2 is required for development of gonadotrophs and thyrotrophs but has not been used for classification of pituitary tumors. Because of genomic paralogy of GATA2 and GATA3, we postulated that GATA3 immunohistochemistry may detect GATA2 in the adenohypophysis. We examined 151 tumors originating from Ondokuz Mayis University, Turkey (n = 83) and University Health Network, Canada (n = 68). Initially, 83 tumors (26 gonadotroph, 24 somatotroph, 17 corticotroph, 12 lactotroph, 2 poorly differentiated Pit-1 lineage tumors that expressed TSH and 2 null cell tumors) from Ondokuz Mayis University were investigated with the GATA3 monoclonal antibody L50-823. Retrospective review of the files of University Health Network identified 68 tumors (43 gonadotroph, 3 somatotroph, 2 lactotroph, 1 mammosomatotroph, 9 corticotroph, 7 poorly differentiated Pit-1 lineage tumors with TSH expression, 2 plurihormonal tumors with TSH expression and 1 null cell tumor) that were examined with the same GATA3 antibody and served as a validation cohort. All somatotroph, lactotroph and mammosomatotroph tumors and the null cell tumors were negative for GATA3. Sixty-eight (98.5%) gonadotroph tumors were positive for GATA3; 64 had diffuse reactivity. Two plurihormonal tumors with TSH expression and eight (88.8%) poorly differentiated Pit-1 lineage tumors with variable TSH expression were positive for GATA3. One of 26 (3.8%) corticotroph tumors was diffusely positive for GATA3. This study shows that GATA3 immunoreactivity is characteristic of pituitary gonadotroph and TSH-producing tumors. This finding expands the pattern of transcription factors that are used to classify adenohypophysial tumors and is important in the differential diagnosis of sellar tumors, as GATA3 expression is also a feature of primary sellar paragangliomas as well as carcinomas that may metastasize to the sella.

Non-Muscle Invasive Papillary Urothelial Carcinoma Metastatic to the Mandible

Urothelial carcinoma, the most common histologic subtype of bladder cancer in the United States, most frequently presents as non–muscle invasive disease. Initially, therapy involves transurethral endoscopic resection and subsequent intravesical therapies with extended surveillance for high-risk disease. Even with the best treatments, recurrence and progression can occur. However, metastasis of non–muscle invasive bladder cancer to distant sites without evidence of progression or regional metastasis is rare. In this article, we present the case of a patient with high-grade papillary urothelial carcinoma who developed an unusual metastasis to the mandible, confirmed by GATA-3 immunostaining, over 4 years after initial transurethral resection. Prior to the development of metastatic disease, this patient had no evidence of local recurrence during maintenance Bacillus Calmette-Guerin intravesical therapy and concurrent surveillance. Positron emission tomography-computed tomography taken after presentation with mandibular metastasis did not show any evidence of regional metastasis. This case highlights an unusual location for distant metastasis of urothelial carcinoma occurring in a patient without evidence of muscle invasive disease or regional metastasis. We additionally highlight the utility of GATA-3 immunostaining in identifying urothelial carcinoma histologically.

GATA3 as a master regulator and therapeutic target in ovarian high-grade serous carcinoma stem cells

Ovarian high-grade serous carcinoma (HGSC) is the most lethal gynecological malignancy. Prevailing evidences suggest that drug resistance and recurrence of ovarian HGSC are caused by the presence of cancer stem cells. Therefore, targeting cancer stems is appealing, however, all attempts to date, have failed. To circumvent this limit, we analyzed differential transcriptomes at early differentiation of ovarian HGSC stem cells and identified the developmental transcription factor GATA3 as highly expressed in stem, compared to progenitor cells. GATA3 expression associates with poor prognosis of ovarian HGSC patients, and was found to recruit the histone H3, lysine 27 (H3K27) demethylase, UTX, activate stemness markers, and promote stem-like phenotypes in ovarian HGSC cell lines. Targeting UTX by its inhibitor, GSKJ4, impeded GATA3-driven stemness phenotypes, and enhanced apoptosis of GATA3-expressing cancer cells. Combinations of gemcitabine or paclitaxel with GSKJ4, resulted in a synergistic cytotoxic effect. Our findings provide evidence for a new role for GATA3 in ovarian HGSC stemness, and demonstrate that GATA3 may serve as a biomarker for precision epigenetic therapy in the future.

Strong androgen receptor expression is not useful in distinguishing GATA3 + metastases

GATA binding protein 3 (GATA3) immunohistochemical expression is commonly considered to be a sensitive and specific diagnostic marker for breast and urothelial carcinomas in surgical pathology practice. However, since its expression has been also demonstrated in other tumors, GATA3 should be better used in conjunction with other immunohistochemical markers to establish tumor primitivity in metastatic setting. Interestingly, GATA3 expression seems to be significantly correlated with androgen receptor (AR) expression in breast carcinoma. In addition, strong AR expression -defined as immunohistochemical positivity in more than 60% of tumor cells- was suggested to be 100% specific for breast origin in GATA3+ metastases. The aim of this study was to verify whether strong AR expression may actually be useful to determine primivity in GATA3+ metastatic setting. Thus, we investigated AR and GATA3 immuno-expression in a cohort of metastatic tumors derived from urothelial, breast, endometrial and salivary gland carcinomas. We did not find any GATA3 or AR expression in the metastases from endometrial or salivary gland carcinomas, while GATA3 expression was seen in the majority of metastases from urothelial or breast carcinomas. In addition, strong AR expression was seen in 73% and in 47% of metastatic breast and urothelial carcinomas, respectively. On the whole, our findings confirm that GATA3 is sensitive and specific for breast and urothelial origin in metastatic setting. According to our results, strong AR expression is not useful to distinguish breast from urothelial primitivity, as previously suggested.

The Diagnosis and Clinical Significance of Paragangliomas in Unusual Locations

Paragangliomas are neuroendocrine neoplasms, derived from paraganglia of the sympathetic and parasympathetic nervous systems. They are most commonly identified in the head and neck, being most frequent in the carotid body, followed by jugulotympanic paraganglia, vagal nerve and ganglion nodosum, as well as laryngeal paraganglia. Abdominal sites include the well-known urinary bladder tumors that originate in the Organ of Zuckerkandl. However, other unusual sites of origin include peri-adrenal, para-aortic, inter-aortocaval, and paracaval retroperitoneal sites, as well as tumors in organs where they may not be expected in the differential diagnosis of neuroendocrine neoplasms, such as thyroid, parathyroid, pituitary, gut, pancreas, liver, mesentery, lung, heart and mediastinum. The distinction of these lesions from epithelial neuroendocrine neoplasms is critical for several reasons. Firstly, the determination of clinical and biochemical features is different from that used for epithelial neuroendocrine tumors. Secondly, the genetic implications are different, since paragangliomas/pheochromocytomas have the highest rate of germline susceptibility at almost 40%. Finally, the characterization of metastatic disease is unique in these highly syndromic lesions. In this review, we summarize updated concepts by outlining the spectrum of anatomic locations of paragangliomas, the importance of morphology in establishing the correct diagnosis, the clinical implications for management, and the impact of genetics on the distinction between multifocal primary tumors compared with malignant disease.

Evaluation of Carcinoma of Unknown Primary on Cytologic Specimens

Carcinoma of unknown primary is defined as metastatic carcinoma without a clinically obvious primary tumor. Determining the tissue of origin in carcinoma of unknown primary is important for site-directed therapy. Immunohistochemistry is the most widely used tool for the work-up of metastases, but molecular profiling assays are also available. This review provides an overview of immunohistochemical stains in the work-up of metastatic carcinoma, with a focus on newer site-specific markers, and discusses the role of gene expression profiling assays for determining tissue of origin. The utility of cytopathology specimens in the evaluation of carcinoma of unknown primary also is highlighted.

Immunohistochemical Biomarkers in Thyroid Pathology

The application of immunohistochemistry to the diagnosis of thyroid lesions has increased as new biomarkers have emerged. In this review, we discuss the biomarkers that are critical for accurate diagnosis, prognosis, and management. Immunohistochemical markers are used to confirm that an unusual tumor in the thyroid is indeed of thyroid origin, either of follicular epithelial or C-cell differentiation; the various mimics include nonthyroidal lesions such as parathyroid tumors, paragangliomas, thymic neoplasms, and metastatic malignancies. Tumors of thyroid follicular epithelial cells can be further subclassified using a number of immunohistochemical biomarkers that can distinguish follicular-derived from C-cell lesions and others that support malignancy in borderline cases. The use of mutation-specific antibodies can distinguish papillary carcinomas harboring a BRAF^V600E mutation from RAS-like neoplasms. Immunostains have been developed to further identify molecular alterations underlying tumor development, including some rearrangements. Altered expression of several biomarkers that are known to be epigenetically modified in thyroid cancer can be used to assist in predicting more aggressive behavior such as a propensity to develop locoregional lymphatic spread. Immunohistochemistry can assist in identifying lymphatic and vascular invasion. Biomarkers can be applied to determine dedifferentiation and to further classify poorly differentiated and anaplastic carcinomas. The rare tumors associated with genetic predisposition to endocrine neoplasia can also be identified using some immunohistochemical stains. The application of these ancillary tools allows more accurate diagnosis and better understanding of pathogenesis while improving prediction and prognosis for patients with thyroid neoplasms.

Gata3 Immunohistochemical Staining is A Useful Marker for Metastatic Breast Carcinoma in Fine Needle Aspiration Specimens

Aims

The utility of GATA3 immunohistochemistry (IHC) as an aid to the cytological diagnosis of metastatic breast carcinoma in fine needle aspiration (FNA) specimens was investigated.

Materials and Methods

Cell block sections from 111 FNA cases of metastatic malignancy were stained for GATA3, including metastases from 43 breast and 44 nonmammary adenocarcinomas, 19 melanomas, 4 urothelial carcinomas, and 1 thyroid medullary carcinoma. Sites sampled included lymph nodes (87), bone (8), liver (5), lung (6), superficial masses (4), and pelvic mass (1).

Results

Ninety-one percent (39/43) of metastatic breast carcinoma cases were positive for GATA3. All estrogen receptor (ER)-positive were also GATA3 positive cases. The majority (9/14; 64%) of ER-negative and 37% (3/8) of triple-negative cases were positive for GATA3. All nonmammary adenocarcinoma cases were negative with the exception of one case of metastatic pancreatic adenocarcinoma. Metastatic melanoma cases were all negative but 75% (3/4) urothelial carcinomas expressed GATA3.

Conclusions

GATA3 IHC staining is a useful addition to IHC panels for FNA samples in specific settings such as distinguishing metastatic breast from lung carcinoma or melanoma.

Immunohistochemical Analysis of the Expression of Breast Markers in Basal-like Breast Carcinomas Defined as Triple Negative Cancers Expressing Keratin 5

Estrogen and progesterone receptors are possible markers for suggesting a mammary origin of metastatic carcinoma, but are useless in cases of triple negative breast cancers (TNBC). Five other potential markers of breast origin were investigated on tissue microarrays in a series of TNBCs showing keratin 5 expression, consistent with a basal-like phenotype. GATA-3 staining was observed in 82 of 115 triple negative cases (71.3%) including 23 cases with >5% staining. Mammaglobin staining was detected in 30 cases (26.0%) including 12 with >5% staining. GCDFP-15 was seen in 23 cases (20.0%) including 9 with >5% staining. NY-BR-1 positivity was present in 7 cases (6.0%) including 3 patients with >5% staining. BCA-225 staining was observed in 74 cases (64.3%); however this latter marker lacks also specificity owing to the reported widespread staining in other malignancies. GATA-3, mammaglobin and GCDFP-15 coexpression was seen in one case (0.9%), whereas GATA-3 and mammaglobin or mammaglobin and GCDFP-15 coexpression was present in 2 and 2 cases (1.7%), respectively. Using at least 5% staining as cut-off, the expression of any of the last 4 markers was 34.7%. The expression of GATA-3, mammaglobin, GCDFP-15 and NY-BR-1 is lower in TNBC-s than in breast carcinomas in general, and this may be even lower in basal-like carcinomas. Although these markers are not fully specific, by using them, a subset of basal-like TNBC-s can be identified as of mammary origin. However, a substantial proportion will not show any staining with any of these markers.

Positivity for GATA3 and TTF-1 (SPT24), and Negativity for Monoclonal PAX8 Expand the Biomarker Profile of the Solid Cell Nests of the Thyroid Gland

Solid cell nests (SCNs) are usually distinguished on conventional H&E-stained sections; however, the morphological heterogeneity in SCNs and hyperplasia of these ultimobranchial body remnants can mimic other diagnostic entities including but not limited to papillary microcarcinoma. In order to confirm the thyroid follicular epithelial origin and exclude the possibility of SCNs, most diagnosticians use immunohistochemical biomarkers of thyroid follicular epithelial cells and/or those of SCNs. While the expression profile of monoclonal PAX8 has not been reported previously in SCNs, the status of TTF-1 expression using the 8G7G3/1 clone has been inconsistent among several studies. Given the potential diagnostic pitfalls, this series investigated the expression profile of GATA3, monoclonal PAX8, and TTF-1 (SPT24), along with p63, p40, monoclonal calcitonin, monoclonal CEA, and HBME-1 in a tissue microarray (TMA) of 56 SCNs. SCNs were all diffusely and strongly positive for TTF-1 (SPT24), p63, and p40, and were negative for monoclonal PAX8 and calcitonin. Positivity for GATA3 and monoclonal CEA was identified in 41 (73.2%) and 36 (64.3%) of SCNs. In addition, 18 (32.1%) SCNs displayed HBME-1 reactivity. These findings expand the immunohistochemical correlates of SCNs by demonstrating positivity for GATA3 and TTF-1 (SPT24), and negativity for monoclonal PAX8. The identification of monoclonal CEA expression and HBME-1 in SCNs also underscores the limitations of these select biomarkers in the distinction of C cell proliferations and papillary microcarcinoma, respectively. The findings of this series also suggest that positivity for TTF-1 (SPT24) alone should not be used to confirm the thyroid follicular epithelial origin. Therefore, the combined use of TTF-1 (SPT24) and monoclonal PAX8 in association with p63 or p40 provides an accurate distinction of SCNs.

Lung and Mediastinum

Fine needle aspiration and small tissue biopsies have become a primary modality to achieve a definitive diagnosis of a mass-like lesion of the lung and mediastinum. This chapter delineated cytologic and histologic features of common and rare neoplastic and nonneoplastic mass-like lesions of the lung and mediastinum. The utilities and pitfalls of commonly used diagnostic immunohistochemical (IHC) stains, such as TTF1, Napsin A, p40 and CK5/6, and small diagnostic IHC panels, were described. Multiple challenging and yet practical cases at the end of the chapter were used to reemphasize important points illustrated throughout the chapter.

Vasitis nodosa and related lesions: a modern immunohistochemical staining profile with special emphasis on novel diagnostic dilemmas

Vasitis nodosa is a benign proliferation of vas deferens epithelium, thought to be a response to trauma or obstruction, usually vasectomy. Although histologic features mimic malignancy, diagnosis is usually straightforward due to the clinical context. We analyzed 21 specimens with vasitis or epididymitis nodosa with antibodies to PAX8, CD10, p63, α-methyl-acyl-coA-racemase (AMACR), GATA3, prostein, NKX3.1, and prostate-specific antigen (PSA). Two diagnostically problematic cases included (1) florid bladder muscle involvement after prostatectomy and (2) involvement of the ampulla and ejaculatory duct in a radical prostatectomy specimen. Vasitis nodosa was excluded in 3 additional histologic mimics (2 post-treatment prostate cancers and 1 bladder cancer). PAX8 yielded consistent positive (100%) nuclear staining in the proliferative glands of vasitis nodosa, often stronger and more uniform than native vas deferens. CD10 labeling was common but also labeled secretions and other structures. Labeling for p63 was often basally located in glands with a multilayered appearance, but often markedly attenuated or lacking in the proliferative glands compared to native epithelium. AMACR positivity was variable but often present (19/21). PSA, prostein, and NKX3.1 were consistently negative. Rare problematic cases of vasitis nodosa include "invasion" of the ejaculatory duct at the prostate and involvement of bladder muscle after prostatectomy. The proliferative vasitis nodosa glands often have a prostate cancer-like staining pattern with variable AMACR positivity and negative or patchy p63. However, reliable positivity for PAX8, patchy GATA3, and negative staining for PSA, NKX3.1, and prostein aid in distinguishing from prostate cancer and tubular variants of bladder cancer.

Usefulness of GATA-3 as a marker of seminal epithelium in prostate biopsies

OBJECTIVES

The incidental presence of seminal vesicle epithelium in prostate needle biopsies is generally recognisable through routine microscopy. However, the biopsy can sometimes be erroneously interpreted as malignant due to its architectural and cytological characteristics, and immunohistochemistry can be useful for correctly identifying the biopsy. Our objective was to analyse the potential usefulness of GATA-3 as a marker of seminal epithelium.

MATERIAL AND METHODS

Through immunohistochemistry with a monoclonal anti-GATA-3 antibody (clone L50-823), we studied seminal vesicle sections from 20 prostatectomy specimens, 12 prostate needle biopsies that contained seminal vesicle tissue and 68 prostate biopsies without seminal vesicle epithelium, 36 of which showed adenocarcinoma.

RESULTS

Staining for GATA-3 was intense in the 20 seminal vesicles of the prostatectomy specimens and in the 12 prostate needle biopsies that contained seminal epithelium. In the 60 biopsies without a seminal vesicle, GATA-3 was positive in the prostate basal cells and even in the secretory cells (57 cases), although with less intensity in 55 of the cases. One of the 36 prostatic adenocarcinomas tested positive for GATA-3.

CONCLUSIONS

The intense immunohistochemical expression of GATA-3 in the seminal vesicle epithelium can help identify the epithelium in prostate biopsies. This marker is also positive in the basal cells of healthy prostates and, with less intensity, in the secretory cells. Positivity, weak or moderate, is observed on rare occasions in prostatic adenocarcinomas.

Adrenal ganglioneuroma: What you need to know

Adrenal ganglioneuromas (GNs) constitute rare, differentiated tumors which originate from neural crest cells. GNs are usually hormonally silent and tend to be discovered incidentally on imaging tests. Adrenalectomy is the gold standard for the treatment of primary adrenal GNs. Nevertheless, preoperative differential diagnosis of GNs remains extremely challenging, and thus histopathological examination is required in order to confirm the diagnosis of GN. Overall, prognosis after surgical resection seems to be excellent, without any recurrences or need for adjuvant therapy.

Transcription factor MafB may play an important role in secondary hyperparathyroidism

The transcription factor MafB is essential for development of the parathyroid glands, the expression of which persists after morphogenesis and in adult parathyroid glands. However, the function of MafB in adult parathyroid tissue is unclear. To investigate this, we induced chronic kidney disease (CKD) in wild-type and MafB heterozygote (MafB+/-) mice by feeding them an adenine-supplemented diet, leading to secondary hyperparathyroidism. The elevated serum creatinine and blood urea nitrogen levels in heterozygous and wild-type mice fed the adenine-supplemented diet were similar. Interestingly, secondary hyperparathyroidism, characterized by serum parathyroid hormone elevation and enlargement of parathyroid glands, was suppressed in MafB+/- mice fed the adenine-supplemented diet compared to similarly fed wild-type littermates. Quantitative RT-PCR and immunohistochemical analyses showed that the increased expression of parathyroid hormone and cyclin D2 in mice with CKD was suppressed in the parathyroid glands of heterozygous CKD mice. A reporter assay indicated that MafB directly regulated parathyroid hormone and cyclin D2 expression. To exclude an effect of a developmental anomaly in MafB+/- mice, we analyzed MafB tamoxifen-induced global knockout mice. Hypocalcemia-stimulated parathyroid hormone secretion was significantly impaired in MafB knockout mice. RNA-sequencing analysis indicated PTH, Gata3 and Gcm2 depletion in the parathyroid glands of MafB knockout mice. Thus, MafB appears to play an important role in secondary hyperparathyroidism by regulation of parathyroid hormone and cyclin D2 expression. Hence, MafB may represent a new therapeutic target in secondary hyperparathyroidism.

Evaluation and comparison of staining patterns of factor XIIIa (AC-1A1), adipophilin and GATA3 in sebaceous neoplasia

BACKGROUND

Reliable nuclear immunohistochemical stains for sebaceous neoplasms have not been readily available. Positive nuclear staining has been reported for GATA3 and factor XIIIa (AC-1A1). We sought to determine the diagnostic utility of these nuclear stains by comparing their staining pattern to adipophilin, a consistently positive cytoplasmic stain.

METHODS

Cases with the diagnosis of sebaceous hyperplasia, sebaceous adenoma, sebaceous epithelioma/sebaceoma, sebaceous carcinoma, and nonsebaceous neoplasms (basal cell carcinoma and squamous cell carcinoma) were examined. Intensity and extent of staining of the basal cells and mature sebocytes were evaluated for each stain.

RESULTS

Factor XIIIa (AC-1A1) was 87.3% sensitive and 95.1% specific for all sebaceous neoplasms sand showed high inter-observer reliability. Adipophilin was 83.2% sensitive and 87.8% specific. GATA3 was the least sensitive (80.9%) and specific (75.6%) marker. When factor XIIIa was compared against composite staining of all three markers its staining was still uniquely significant (P = .0210).

CONCLUSION

Factor XIIIa (AC-1A1) is a sensitive and specific nuclear marker for sebaceous differentiation. Its diagnostic utility exceeds that of adipophilin. Factor XIIIa should be included in the expanding group of immunohistochemical and special stains which can be utilized to aid in the diagnosis of sebaceous neoplasms.

Metastasis to the pancreas and stomach from a breast cancer primary: a case report

A 60-year-old female with an unknown family history initially presented with signs and symptoms concerning for gastrointestinal cancer. Regular breast cancer screening and subsequent work-up around this time demonstrated the presence of T2N1 stage II triple positive ductal adenocarcinoma of the left breast. Follow-up imaging for her gastrointestinal symptoms demonstrated a 3.5 cm solitary mass in the pancreas and diffuse thickening of the stomach wall. Biopsies of the gastrointestinal lesions were identified as metastatic foci of the breast cancer primary. Breast cancer metastases to the stomach and to the pancreas are both very rare events. Of the breast cancer primaries that do metastasize to the gastrointestinal system, it is unusual for the primary to be ductal adenocarcinoma. The rapid succession of diagnosing the primary source of breast cancer simultaneously with its metastases is also unusual. Timely identification and appropriate management of these rare metastases was made possible due to routine breast cancer screening.

GATA3 is a sensitive marker for primary genital extramammary paget disease: an immunohistochemical study of 72 cases with comparison to gross cystic disease fluid protein 15

BACKGROUND

GATA-binding protein 3 (GATA3) has been identified as a sensitive marker for breast carcinoma but its sensitivity in primary genital extramammary Paget diseases (EMPDs) has not been well studied.

METHODS

Here we investigated immunohistochemical expression of GATA3 in 72 primary genital EMPDs (35 from female, 37 from male; 45 with intraepithelial disease only, 26 with both intraepithelial disease and invasive adenocarcinoma including 14 also metastasis, 1 with metastatic adenocarcinoma only for study). We also compared GATA3 to gross cystic disease fluid protein 15 (GCDFP15) for their sensitivity.

RESULTS

Positive GATA3 staining was seen in all 71 (100%) intraepithelial diseases, 25/26 (96%; female 10/10, male 15/16) invasive adenocarcinomas and 14/15 (93%; female 3/3, male 11/12) metastatic adenocarcinomas, respectively. Positive GCDFP15 staining was seen in 46/71 (65%; female 28/34 or 82%, male 18/37 or 49%) intraepithelial diseases, 20/26 (77%; female 9/10, male 11/16) invasive adenocarcinomas, and 12/15 (80%; female 2/3, male 10/12) metastatic adenocarcinomas, respectively (GATA3 versus GCDFP15: p < 0.01 for both intraepithelial disease and invasive adenocarcinoma, p = 0.28 for metastatic adenocarcinoma). In positive-stained cases, GATA3 stained more tumor cells than GCDFP15 (79% versus 25% for intraepithelial disease, 71% vs 34% for invasive adenocarcinoma, 73% vs 50% for metastatic adenocarcinoma, p < 0.01 for all 3 components).

CONCLUSIONS

Our findings indicate that GATA3 is a very sensitive marker for primary genital EMPDs and is more sensitive than GCDFP15.

S100P as a Marker for Urothelial Histogenesis: A Critical Review and Comparison With Novel and Traditional Urothelial Immunohistochemical Markers

S100P, or placental S100, is a member of a large family of S100 proteins and considered to be a promising immunohistochemical marker to support urothelial differentiation. This review synthesizes published data regarding the expression of S100P in urothelial carcinoma across histological grade and variant patterns, and in other malignancies, in an effort to summarize the state of understanding of this marker and evaluate its potential. We provide also a broad comparison of S100P with other contemporary and traditional urothelial markers and outline the potential utility of S100P in various diagnostically challenging scenarios. Taken in context, we recommend that to provide immunohistochemical support for consideration of urothelial differentiation, S100P may be included in a panel of markers (due to its high sensitivity), with better established (GATA3) and more specific (uroplakin 2) markers, for comparison with corresponding markers of other primary sites under consideration, depending on the clinical context. We emphasize that the overall most appropriate panel for any given case depends on the differential diagnosis engendered by the morphology encountered, and the constellation of clinical findings. As always with immunohistochemical panels, expected positive and negative markers for each diagnostic consideration should be included. Finally, since as of date there are no optimally sensitive or specific markers of urothelial differentiation, all final diagnoses relying on immunohistochemical support should be made in the appropriate clinical and histological context.