WT1 immunoreactivity in breast carcinoma: selective expression in pure and mixed mucinous subtypes

Expression of four cancer-testis antigens in TNBC indicating potential universal immunotherapeutic targets

OBJECTIVE

Immunotherapy is an attractive treatment for breast cancer. Cancer-testis antigens (CTAs) are potential targets for immunotherapy for their restricted expression. Here, we investigate the expression of CTAs in breast cancer and their value for prognosis. So as to hunt for a potential panel of CTAs for universal immunotherapeutic targets.

MATERIAL AND METHODS

A total of 137 breast cancer tissue specimens including 51 triple-negative breast cancer (TNBC) were assessed for MAGE-A4, MAGEA1, NY-ESO-1, KK-LC-1 and PRAME expression by immunohistochemistry. The expression of PD-L1 and TILs was also calculated and correlated with the five CTAs. Clinical data were collected to evaluate the CTA's value for prognosis. Data from the K-M plotter were used as a validation cohort.

RESULTS

The expression of MAGE-A4, NY-ESO-1 and KK-LC-1 in TNBC was significantly higher than in non-TNBC (P = 0.012, P = 0.005, P < 0.001 respectively). 76.47% of TNBC expressed at least one of the five CTAs. Patients with positive expression of either MAGE-A4 or PRAME had a significantly extended disease-free survival (DFS). Data from the Kaplan-Meier plotter confirm our findings.

CONCLUSIONS

MAGE-A4, NY-ESO-1, PRAME and KK-LC-1 are overexpressed in breast cancer, especially in TNBC. Positive expression of MAGE-A4 or PARME may be associated with prolonged DFS. A panel of CTAs is attractive universal targets for immunotherapy.

Axillary Lymph Node Metastasis from Ovarian Carcinoma: A Systematic Review of the Literature

BACKGROUND

Axillary lymph node metastasis is a rare stage IV ovarian carcinoma manifestation. This manuscript aims to systematically review the literature regarding axillary lymph node metastasis from ovarian carcinoma.

METHODS

We searched three medical internet databases (PubMed, Scopus, and Web of Science) for relevant articles published until 22 July 2023. Cases describing supraclavicular or intramammary lymph node metastases and concurrent metastasis to the breast were excluded.

RESULTS

After applying eligibility/inclusion and exclusion criteria, twenty-one manuscripts describing twenty-five cases were included from the English literature. Data were collected and analyzed regarding demographic, clinical, laboratory, radiological, histopathological, and oncological characteristics.

CONCLUSIONS

We analyzed the clinical and oncological characteristics of patients with axillary lymph node metastasis from ovarian carcinoma, presented either as an initial diagnosis of the disease or as a recurrent disease. The analysis we performed showed a significant difference only in the serum CA-125 level (p = 0.004) between the two groups. There was no observed difference in womens' survival.

SOX17: A Highly Sensitive and Specific Immunomarker for Ovarian and Endometrial Carcinomas

PAX8 is the most commonly used immunomarker to link a carcinoma to the gynecologic tract; however, it lacks specificity. Through mining The Cancer Genome Atlas mRNA expression profile data, we identified SOX17 as a potential specific marker at the mRNA level for gynecologic tumors. To evaluate the utility of this marker in the identification of the gynecologic origin of a given carcinoma, we performed immunochemical staining in a large cohort of ovarian and endometrial cancer cases (n = 416), together with a large cohort of solid tumors from other organs (n = 1544) in tissue microarrays. Similar to PAX8, SOX17 was highly expressed in different subtypes of ovarian carcinoma (97.5% for SOX17 vs 97% for PAX8 in serous carcinoma, 90% vs 90% in endometrioid carcinoma, and 100% vs 100% in clear cell carcinoma), except for mucinous carcinoma (0% vs 27%), and was also highly expressed in different subtypes of endometrial carcinoma (88% vs 84% in endometrioid carcinoma, 100% vs 100% in serous and clear cell carcinoma). SOX17 was not expressed in thyroid and renal cell carcinomas, whereas PAX8 expression was high (86% and 85%, respectively). In addition, SOX17 was expressed at low levels in cervical adenocarcinoma (20%) and had no expression in cervical squamous carcinoma, mesothelioma, and carcinomas from the breast, lung, pancreas, colon, stomach, liver, bladder, and salivary gland. Our data indicate that SOX17 is not only a sensitive but also a specific marker for the origin of ovarian and endometrial carcinomas.

Lobular Carcinoma of the Breast Metastatic to the Ovary: A Clinicopathologic Study of 38 Cases

We evaluated the clinicopathologic features of 38 cases of metastatic lobular (n=33) or predominantly lobular (n=5) carcinoma involving the ovary. The patients were from 39 to 91 years of age (mean: 53 y). In 2 cases, the breast primary and ovarian metastasis were diagnosed synchronously, and in 5, the breast primary was only discovered after the metastatic carcinoma in the ovary was found. In the majority of cases (79%), both ovaries were involved; the mean ovarian tumor size was 5.9 cm. The ovarian tumors demonstrated a range of architectural patterns including macronodular (71%), diffuse/solid growth (87%), single-cell infiltration (87%), cords (74%), and small nests/clusters (50%). Nine cases demonstrated focal signet ring cell morphology. The associated stromal reaction ranged from none to marked, with almost half of cases demonstrating a marked stromal response, largely prominent sclerosis. A variety of neoplasms, most typically sex cord-stromal tumors, lymphoma/leukemia, and desmoplastic small round cell tumor, may enter the differential. In addition to the obvious help afforded in most cases by the clinical history, a combination of judicious sampling, particularly to unearth the delicate cords or single-cell growth of lobular carcinoma, appropriate consideration of the cytologic features of the neoplastic cells, and immunohistochemistry can resolve the diverse issues in differential diagnosis that may arise.

Clinicopathological significance of WT1 expression in invasive breast carcinoma with >90% mucinous component

AIMS

This study was aimed to investigate the clinicopathological significance of immunohistochemical (IHC) Wilm's tumour 1 (WT1) expression in invasive breast carcinoma with >90% mucinous components.

METHODS

One hundred specimens of invasive breast carcinoma with >90% mucinous component were collected. All H&E-stained slides were reviewed, and the clinicopathological data, including sex, age, tumour size, nuclear grade, histological grade, growth pattern and lymph node (LN) status, were collected. IHC staining of WT1, oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 was performed. Fluorescence in situ hybridisation was used to verify the amplification of the HER2 gene. The relationship between WT1 expression and clinicopathological features was analysed statistically.

RESULTS

WT1 expression was detected in 67% (67/100) of invasive breast carcinoma with >90% mucinous components. WT1 expression was significantly associated with low-to-intermediate nuclear grade/histological grade, ER and PR positivity, HER2 negativity, Ki-67 proliferation index <30% and noLN metastasis (all p<0.001). Micropapillary architecture was observed in 80% of cases. WT1 expression was not significantly correlated with different percentage of micropapillary components (p=0.422). None of the histological grade 3 tumours, tumours with HER2 overexpression/amplification and triple-negative specimens showed WT1 expression.

CONCLUSIONS

WT1 expression was significantly related with low-intermediate nuclear/histological grade, ER positivity, HER2 negativity, a lower Ki-67 proliferation index and no LN metastasis in invasive breast carcinoma with >90% mucinous component. The micropapillary growth pattern in this type of tumour did not show a specific relationship with WT1 expression.

Endosalpingiosis Is Negative for GATA3

CONTEXT.—

Endosalpingiosis is a benign Müllerian inclusion that can mimic metastatic low-grade mammary carcinoma, particularly when encountered in axillary lymph nodes excised for breast cancer staging. Immunohistochemistry can be useful in histologically ambiguous cases, and a targeted immunopanel should include a marker of gynecologic tract origin and a marker of mammary origin. GATA3 is a sensitive immunomarker for breast carcinoma, but the immunoreactivity of GATA3 in endosalpingiosis has not been systematically evaluated.

OBJECTIVE.—

To evaluate whether GATA3 immunohistochemistry could be used to differentiate endosalpingiosis from metastatic mammary carcinoma.

DESIGN.—

Whole slide sections of 15 cases of endosalpingiosis involving nonneoplastic tissues were subjected to GATA3 immunohistochemistry. Nuclear GATA3 labeling was scored as percentage and intensity labeling, with any labeling considered positive; GATA3 labeling was recorded in all cells present in the sections.

RESULTS.—

Half (47%, n = 7 of 15) of the endosalpingiosis cases involved lymph nodes (2 axillary, 5 pelvic) and half (53%, n = 8 of 15) involved pelvic organs or soft tissue (3 myometrial, 2 paratubal, 2 periadnexal soft tissue, and 1 pelvic sidewall). GATA3 immunohistochemistry was negative in all cases of endosalpingiosis, with intact, positive control labeling in lymphocytes. The benign fallopian tube epithelium present on the sections of paratubal endosalpingiosis displayed focal (<5%), weak labeling for GATA3, specifically within the ciliated and secretory cells.

CONCLUSIONS.—

These findings support the diagnostic utility of GATA3 immunohistochemistry and its use in a targeted immunopanel to resolve the differential diagnosis of metastatic low-grade mammary carcinoma (GATA3+) and nodal endosalpingiosis (GATA3-).

Novel uses of immunohistochemistry in breast pathology: interpretation and pitfalls

Immunohistochemistry is an essential component of diagnostic breast pathology. The emergence of novel assays and applications is accompanied by new interpretation criteria and potential pitfalls. Immunohistochemistry assists in supporting breast origin for primary or metastatic carcinomas and identifying non-mammary metastases to the breast; however, no single immunostain is perfectly sensitive nor specific. GATA3 and Sox10 are particularly useful immunostains to identify triple negative breast carcinoma, which are often negative for other markers of mammary differentiation. Sox10 labeling is a major potential diagnostic pitfall, as Sox10 and S-100 label both triple negative breast carcinoma and metastatic melanoma; a pan-cytokeratin immunostain should always be included for this differential diagnosis. Novel immunohistochemistry serves as surrogates for the molecular alterations unique to several of special-type breast carcinomas, including the use of MYB in adenoid cystic carcinoma, pan-TRK in secretory carcinoma, and mutant IDH2 in tall cell carcinoma with reversed polarity (TCCRP). In addition, PD-L1 immunohistochemistry is an emerging, albeit imperfect, biomarker for breast cancer immunotherapy, with different assay parameters and scoring criteria in breast carcinoma compared to other tumor types. The expanding repertoire of novel immunohistochemistry provides additional diagnostic tools and biomarkers that improve diagnostic breast pathology and patient care.

PAX8 Expression in Breast Cancer

PAX8 expression is frequently detected in renal, thyroidal, and Müllerian carcinomas, and PAX8 immunohistochemistry is often used to confirm the origin of these tumors. Tumors metastatic to the breast may masquerade as primary breast lesions. PAX8 is strongly expressed in tumors of Müllerian origin and largely negative in breast primaries, but an immunohistochemical expression of PAX8 in breast cancer has not been systematically evaluated in a large series. We analyzed 266 cases of invasive carcinoma of the breast on tissue microarrays and whole tissue sections with a PAX8 monoclonal antibody. Both the extent (focal or diffuse) and intensity (weak, moderate, or strong) of nuclear staining were assessed in the tumor cells. In total, 16 cases (6.02%) were positive for PAX8 (12 with weak and 4 with moderate staining). Expression was diffuse in 7 cases and focal in 9 cases. All 16 PAX8-positive tumors were histologic grade III invasive ductal carcinomas, 13 of these were triple-negative, 2 were HER2-positive, only and 1 was progesterone receptor-positive only. Strong PAX8 nuclear expression was not seen in any of the cases. PAX8 was negative in breast tumors with neuroendocrine features. Our study demonstrated a low rate of PAX8 expression in breast cancer. When present, PAX8 expression was only seen in high-grade invasive ductal carcinomas, mostly triple-negative. The presence of PAX8 immunoreactivity alone cannot exclude mammary origin, especially when only weak to moderate staining is observed, so the correlation with available clinical and pathologic data helps to ensure an accurate diagnosis.

Metastases to the Breast from Extramammary Nonhematological Malignancies: Case Series

Objective

This article aims to provide a better understanding of ultrasonography and immunohistochemistry of secondary nonhematological tumors of breast.

Methods

The study reviewed the ultrasound findings and immunohistochemical features of nonhematological metastatic breast tumor cases found in patients of West China Hospital, Sichuan University from 2007 to 2019. Each case was categorized as secondary breast malignancy using histopathological results.

Results

Fourteen cases were identified from West China Hospital database. Ten cases originated in the lung, 2 cases in the stomach, 1 case in the ovary and 1 case of neuroendocrine carcinomas. Fourteen masses were evaluated. Ultrasound findings showed that tumors were hypoechoic (14/14), irregular (13/14), indistinct margin (13/14), along a long axis parallel to the skin (11/14), lacked vascularity via color doppler flow imaging (9/14). Eight cases showed no posterior features. Calcification was found in 1 case of lung adenocarcinoma that had metastasized to the breast. Abnormal axillary lymph nodes were detected in 5 cases. Immunohistochemical analysis showed that estrogen receptor (ER) and progesterone receptor (PR) were both negative in 11 cases, including gastric and lung cancer metastasis. One case of ovarian metastasis was positive for ER and negative for PR. Six patients were positive for cytokeratin 7 (CK7) and negative for cytokeratin 20 (CK20), including lung and ovarian carcinoma metastasis. Thyroid transcription factor-1 (TTF-1) was positive in 9 of 10 pulmonary carcinoma metastases. The patient of ovarian metastasis was positive for Wilms' tumour 1 (WT-1) and carbohydrate antigen 125 (CA125). Two cases from gastric metastasis were positive for caudal-type homeobox 2 (CDX2).

Conclusion

Although breast ultrasound is not useful in distinguishing metastases from primary breast cancer, it is helpful in diagnosing breast lesions as oncological diseases and provide evidence for further examination of patients. Immunohistochemistry plays an important role in distinguishing secondary breast cancer from primary, especially in patients without tumor history.

Assessment of stromal tumor infiltrating lymphocytes and immunohistochemical features in invasive micropapillary breast carcinoma with long-term outcomes

PURPOSE

We studied the long-term outcomes of invasive micropapillary carcinoma (IMPCs) of the breast in relation to stromal tumor infiltrating lymphocytes (sTILs), prognostic biomarkers and clinicopathological features.

METHODS

Stage I-III IMPCs treated with upfront surgery at our institution (January 2000 and December 2016) were included. Central pathology review was performed and sTILs (including zonal distribution and hot spot analysis) and tumor-associated plasma cells (TAPC) were evaluated. Expression of P53, BCL2, FOXP3, and WT1, which are variably linked to breast cancer prognosis, was measured by immunohistochemistry using tissue microarrays. Time-to-event endpoints were distant recurrence free interval (DRFI) and breast cancer-specific survival (BCSS).

RESULTS

We included 111 patients of whom 59% were pure IMPCs. Standard clinicopathological features were comparable between pure and non-pure IMPCs. Overall, the mean sTILs level was 20% with higher proportion of sTILs present at the invasive front. There were no significant differences between pure- and non-pure IMPCs in sTILs levels, nor in the spatial distribution of the hot spot regions or in the distribution of TAPC. Higher sTILs correlated with worse DRFI (HR = 1.55; p = 0.0172) and BCSS (HR = 2.10; p < 0.001).

CONCLUSIONS

Clinicopathological features, geographical distribution of sTILs and TAPC are similar between pure and non-pure IMPCs. Despite a high proportion of grade 3 tumors and lymph node involvement, we observed a low rate of distant recurrences and breast cancer-related death in this cohort of stage I-III IMPCs treated with primary surgery. Caution in interpretation of the observed prognostic correlations is required given the very low number of events, warranting validation in other cohorts.

Histological clues to the diagnosis of metastasis to the breast from extramammary malignancies

AIMS

The aims of this study were to review the histological features useful for the identification of metastases to the breast and to investigate the impression that this diagnosis has become more common.

METHODS AND RESULTS

The histological features of metastases to the breast from 2008 to 2018 were reviewed. Seventy-four biopsies from 66 patients were identified: 1% compared with primary carcinoma of the breast. Non-haematological metastases comprised 0.75% compared with 0.3% in a series from 1996 to 2005. The most common tumour types were pulmonary carcinoma (22), lymphoma (15), melanoma (13), gastrointestinal carcinoma (eight) and serous papillary carcinoma (four). In 73% there were histological features that were not typical of primary mammary carcinoma. Some metastases were histologically similar to breast cancer and the history was essential to making the correct diagnosis. Useful histological clues included small-cell morphology for pulmonary carcinoma, glands containing necrosis for gastrointestinal carcinoma, intranuclear inclusions, marked pleomorphism and spindle cells for melanoma, clear cells for renal carcinoma, papillary architecture for serous papillary carcinoma and sheets of centroblasts or nodules of centroblasts and centrocytes for lymphoma. Useful immunohistochemical markers included TTF-1 for pulmonary carcinoma, S100, melan-A and HMB45 for melanoma, CK20 and CDX2 for colorectal carcinoma, PAX8 and WT1 for serous papillary carcinoma and lymphoid markers for lymphomas, in addition to the absence of expression of mammary markers ER, GATA3 and GCDFP-15.

CONCLUSION

The majority of metastases to the breast have histological clues to the diagnosis. Immunohistochemistry is helpful. This diagnosis is being made more frequently.

Immunohistochemical Expression of Wilms’ Tumor 1 Protein in Human Tissues: From Ontogenesis to Neoplastic Tissues

The human Wilms’ tumor gene (WT1) was originally isolated in a Wilms’ tumor of the kidney as a tumor suppressor gene. Numerous isoforms of WT1, by combination of alternative translational start sites, alternative RNA splicing and RNA editing, have been well documented. During human ontogenesis, according to the antibodies used, anti-C or N-terminus WT1 protein, nuclear expression can be frequently obtained in numerous tissues, including metanephric and mesonephric glomeruli, and mesothelial and sub-mesothelial cells, while cytoplasmic staining is usually found in developing smooth and skeletal cells, myocardium, glial cells, neuroblasts, adrenal cortical cells and the endothelial cells of blood vessels. WT1 has been originally described as a tumor suppressor gene in renal Wilms’ tumor, but more recent studies emphasized its potential oncogenic role in several neoplasia with a variable immunostaining pattern that can be exclusively nuclear, cytoplasmic or both, according to the antibodies used (anti-C or N-terminus WT1 protein). With the present review we focus on the immunohistochemical expression of WT1 in some tumors, emphasizing its potential diagnostic role and usefulness in differential diagnosis. In addition, we analyze the WT1 protein expression profile in human embryonal/fetal tissues in order to suggest a possible role in the development of organs and tissues and to establish whether expression in some tumors replicates that observed during the development of tissues from which these tumors arise.

Expression of tumor-associated antigens in breast cancer subtypes

Objectives

Tumor-associated antigens (TAAs) are frequently overexpressed in several cancer types. The aim of this study was to investigate the expression of TAAs in breast cancer.

Material and methods

A total of 250 selected invasive breast cancers including 50 estrogen receptor (ER)-positive (Luminal B like), 50 triple-negative (TN), 50 ER-positive lobular type, 50 ER- and progesterone receptor (PgR)-positive (Luminal A like) and 50 cerbB2-positive breast cancers, were assessed for New York esophageal squamous cell carcinoma-1 (NY-ESO-1), Wilms tumor antigen (WT-1) and PReferentially expressed Antigen of MElanoma (PRAME) antigen expression by immunohistochemistry (IHC).

Results

A significantly higher expression of cancer testis (CT)-antigens NY-ESO-1 and WT-1 antigen was detected in TN breast cancers compared with ER-positive tumors. NY-ESO-1 overexpression (score 2 + and 3+) assessed by monoclonal and polyclonal antibodies was detected in 9 (18%) TN cancers as compared to 2 (4%) ER-positive tumors (p = 0.002). WT1 over-expression (score 2 + and 3+) was confirmed in 27 (54%) TN tumor samples as compared to 6 (12%) ER-positive (p < 0.0001). PRAME over-expression (score 2 + and 3+) was detected in 8 (16%) HER2 positive tumor samples as compared to no TN and ER-positive cancers (p = 0.0021).

Conclusions

NY-ESO-1 and WT1 antigens are overexpressed in TN breast cancers. Because of the limited therapeutic options for this patient subgroup, CT antigen-based vaccines might prove to be useful for patients with this phenotype of breast cancer.

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Tumor-associated antigens are frequently overexpressed in several cancer types, being also associated with poorer patients’ survival outcomes.

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Our study confirmed that NY-ESO-1 and WT1 antigens are higher expressed in triple-negative than in other breast cancer subtypes.

•

Given the limited therapeutic options for triple-negative breast cancer patients, the assessment of WT1 and NY-ESO-1 antigens expression in breast cancer tissue at surgery may allow to identify patients potentially candidate to adjuvant peptide vaccines, alone or in combination with other systemic therapies.

Axillary Lymph Node Inclusions

Lymph node inclusions can occur in axillary lymph nodes, where they can mimic metastatic breast carcinoma. This article provides an overview of epithelial and nonepithelial lymph node inclusions, including mammary-type glandular inclusions, Mullerian-type glandular inclusions, squamous inclusions, mixed glandular-squamous inclusions, and nodal nevi. The discussion emphasizes the histologic and immunophenotypic features and differential diagnoses of each entity.

Male Breast Cancer

Objectives

A clinicopathologic study with an emphasis on tumor immunohistochemical profile is presented.

Methods

Sixty-one cases of male invasive breast cancers were studied. Median age of the cohort was 65 years.

Results

Ninety-seven percent were estrogen receptor positive+ and 10% human epidermal growth factor receptor 2 positive. The individual diagnostic marker positivity was 98% for GATA-binding protein 3, 95% for androgen receptor, 90% for progesterone receptor, 88% for deleted in pancreatic cancer 4, 75% for gross cystic disease fluid protein 15, 72% for cytokeratin 7, 55% for mammaglobin, and 15% for vimentin and Wilms tumor protein 1. Caudal type homeobox 2 protein, cytokeratin 20, Napsin A, paired box gene 8, prostate-specific antigen, thyroid transcription factor 1, and uroplakin II were negative in all cases. Survival analyses showed tumor stage, receptor status, and Nottingham prognostic index to be prognostic. The overall survival was 70%, but the breast cancer–specific survival was 92% (mean follow-up, 59 months); 33% developed second malignancy. The immunohistochemistry profile was similar to female breast cancers.

Conclusions

The second malignancies in this cohort affected overall survival and suggest the possibility of other germline mutations in addition to BRCA2 in male patients with breast cancer.

Mucinous Carcinoma with Neuroendocrine Differentiation of Salivary Gland Origin

Primary mucinous adenocarcinomas of the salivary gland are rare malignancies defined by aggregates of epithelial cells suspended in large pools of extracellular mucin. We report a case of a giant mucinous adenocarcinoma of salivary gland origin, with low-grade cytoarchitectural features and neuroendocrine differentiation arising in the submental region. Grossly, the tumor measured 12.5 × 13.4 × 8.2 cm and replaced the bone and soft tissues of the anterior oral cavity. Microscopically, the neoplasm was composed of large extracellular pools of mucin, which contained papillary and acinar aggregates, and small nodules of ductal type epithelium with minimal nuclear enlargement, powdery chromatin and little pleomorphism. The nodules comprised 20 % of the tumor and showed morphologic and immunohistochemical evidence of neuroendocrine differentiation. Examination revealed histologic features comparable to mammary gland analogues in mucin predominance, ductal type morphology, expression of estrogen and progesterone receptors, and GATA-3 positivity. This is the first case reported of mucin-rich carcinoma of salivary gland origin exhibiting neuroendocrine differentiation.

The SWI/SNF ATPases Are Required for Triple Negative Breast Cancer Cell Proliferation

The Brahma (BRM) and Brahma-related Gene 1 (BRG1) ATPases are highly conserved homologs that catalyze the chromatin remodeling functions of the multi-subunit human SWI/SNF chromatin remodeling enzymes in a mutually exclusive manner. SWI/SNF enzyme subunits are mutated or missing in many cancer types, but are overexpressed without apparent mutation in other cancers. Here, we report that both BRG1 and BRM are overexpressed in most primary breast cancers independent of the tumor's receptor status. Knockdown of either ATPase in a triple negative breast cancer cell line reduced tumor formation in vivo and cell proliferation in vitro. Fewer cells in S phase and an extended cell cycle progression time were observed without any indication of apoptosis, senescence, or alterations in migration or attachment properties. Combined knockdown of BRM and BRG1 showed additive effects in the reduction of cell proliferation and time required for completion of cell cycle, suggesting that these enzymes promote cell cycle progression through independent mechanisms. Knockout of BRG1 or BRM using CRISPR/Cas9 technology resulted in the loss of viability, consistent with a requirement for both enzymes in triple negative breast cancer cells.

Practical Applications in Immunohistochemistry: Carcinomas of Unknown Primary Site

CONTEXT

-Identification of the site of origin of carcinoma of unknown primary using immunohistochemistry is a frequent requirement of anatomic pathologists. Diagnostic accuracy is crucial, particularly in the current era of targeted therapies and smaller sample sizes.

OBJECTIVES

-To provide practical guidance and suggestions for classifying carcinoma of unknown primary using both proven and new antibodies, as well as targeting panels based on integration of morphologic and clinical features.

DATA SOURCES

-Literature review, the authors' practice experience, and authors' research.

CONCLUSIONS

-With well-performed and interpreted immunohistochemistry panels, anatomic pathologists can successfully identify the site of origin of carcinoma of unknown primary. It is crucial to understand not only the diagnostic uses of the many available antibodies but also the potential limits and pitfalls.

Association of Wilms' tumor 1 gene single-nucleotide polymorphism rs16754 with colorectal cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related mortality worldwide. Our recent study demonstrated that the expression of Wilms' tumor 1 gene (WT1) is associated with surgical outcome in CRC patients. The present study aimed to investigate the genetic association of the single-nucleotide polymorphism rs16754 in the WT1 gene with the occurrence of CRC, using an age-matched case-control study design. In addition, the correlation between genotype and WT1 expression was investigated. Genomic DNA samples from 104 CRC cases, aged 15-65 years, and 208 healthy controls, were genotyped for rs16754 using the TaqMan genotyping method. The genotype distribution conformed to the Hardy-Weinberg equilibrium (P=0.80). The overall minor allele frequency (MAF) of rs16754 (allele A) was 0.33. The MAF among CRC cases was significantly higher compared with that in controls (0.39 vs. 0.31, respectively; P=0.03). The AA genotype was significantly associated with the disease (odds ratio = 2.51, 95% confidence interval: 1.24-5.07, P=0.01). Cases with the AA genotype exhibited a significantly poorer 3-year overall survival (60%), compared with those with the GG or GA genotypes (80%) (log-rank test, P<0.01). Reverse transcription quantitative polymerase chain reaction analysis demonstrated that the expression of WT1 in tumor tissues was higher compared with that in normal tissue; however, there were no significant differences in its expression among different genotypes. Therefore, rs16754 was found to be associated with the occurrence and prognosis of CRC in our subjects.

WT1 expression in endocrine mucin-producing sweat gland carcinoma: a study of 13 cases

BACKGROUND

Endocrine mucin-producing sweat gland carcinoma (EMPSGC), a low-grade sweat gland carcinoma with a predilection for the eyelids, often shows areas of benign eccrine cysts, atypical intracystic proliferation and associated mucinous carcinoma, suggesting tumor progression. Wilms tumor 1 (WT1) protein, a transcription factor, is overexpressed in many tumors and plays a role in oncogenesis.

METHODS

A computer-based search for tumors diagnosed between 1989 and 2009 was conducted. Clinical data were obtained from pathology reports and patient records. Biopsies were reviewed for histologic features. Immunostaining was performed for WT1, chromogranin, synaptophysin, estrogen receptor (ER), epithelial membrane antigen (EMA), polyclonal carcinoembryonic antigen (P-CEA), cytokeratin 7 (CK7), cytokeratin 20 (CK20) and MIB-1.

RESULTS

Eight women and five men (mean age: 61.2 years; range: 40-77 years) presented with slow-growing eyelid nodules. Cases of EMPSGC were characterized by the presence of dermal nodules with various growth patterns. Adjacent eccrine cysts were present in five patients, atypical epithelial proliferation within the cyst wall in four patients, and an associated mucinous carcinoma in one patient. All tumors were positive for WT1, CK7, ER, P-CEA and EMA and negative for CK20. Tumors were positive for synaptophysin in 12 cases and chromogranin in nine cases. The MIB-1 proliferation index was low in most cases. No WT1 staining was observed in the overlying epidermis, adnexal structures or areas of benign eccrine cyst. WT1 expression was observed in areas of atypical epithelial proliferation, and the neoplastic cells.

CONCLUSIONS

The present study shows WT1 expression in the neoplastic epithelial cells of EMPSGC, areas of atypical intraductal proliferations, and mucinous carcinoma. The absence of WT1 expression in areas of benign eccrine cyst and cutaneous sweat glands suggests WT1 upregulation plays a role in tumor cell proliferation and progression of EMPSGC.

Breast cancer or metastasis? An unusual case of metastatic malignant pleural mesothelioma to the breast

Background

Metastases to the breast from extramammary malignancies are very rare, and ruling out the diagnosis of primary breast tumor is important in order to decide on clinical management and predict prognosis.

Case presentation

Clinical examination revealed in a 49-year-old hairdresser a 3-cm hard lump adherent to the underlying layers in the right breast. Trucut biopsy was performed. Histology showed a solid proliferation of medium-sized neoplastic polygonal cells. Immunohistochemical analysis showed tumor cells diffusely positive for cytokeratin 8/18 and calretinin and focally positive for cytokeratin 5/6 and Wilms’ tumor 1, e-cadherin, and human bone marrow endothelial-1. Estrogen receptors and progesterone receptors were negative. The final diagnosis was metastatic epithelioid malignant pleural mesothelioma.

Conclusions

Immunohistochemistry is an important tool for a conclusive diagnosis of malignant pleural mesothelioma. Owing to the degree of histological and immunohistochemical overlap, a high level of clinical suspicion is essential in order to avoid unnecessary mutilating surgery.

A subset of nondescript axillary lymph node inclusions have the immunophenotype of endosalpingiosis

We report 2 cases of bland, otherwise nondescript axillary lymph node inclusions that have the immunophenotype of endosalpingiosis in patients with concurrent invasive breast carcinomas. Neither inclusion demonstrated the classic morphology of endosalpingiosis with admixed ciliated and secretory cells. Rather, both cases were composed of nondescript cuboidal to columnar bland epithelial cells situated within the lymph node capsule. Whereas both inclusions labeled diffusely for estrogen receptor and lacked evidence of a myoepithelial component, both labeled diffusely for PAX8 and WT-1, which distinguished them from their corresponding concurrent primary mammary carcinomas. These findings suggest that a subset of otherwise nondescript axillary lymph node inclusions represent endosalpingiosis and highlight the utility of PAX8 and WT-1 immunohistochemistry in distinguishing these from metastatic well-differentiated ductal carcinoma.

Axillary metastasis from an occult tubal serous carcinoma in a patient with ipsilateral breast carcinoma: a potential diagnostic pitfall

Axillary nodal metastasis from a nonmammary neoplasia is much rarer than diseases associated with a primary breast carcinoma. However, this has to be considered in the differential diagnosis of nodal disease in patients with a history of breast cancer. Here, we report the case of a 73-year-old female with a past medical history of breast cancer, presenting with an ipsilateral axillary metastatic carcinoma. The immunohistochemical profile of the metastatic lesion was consistent with a high grade serous carcinoma. After undergoing a total abdominal hysterectomy and salpingo-oophorectomy, thorough pathological examination revealed two microscopic foci of serous carcinoma in the right fallopian tube, not detectable by preoperative magnetic resonance imaging. In this context, the poorly differentiated appearance of the metastatic tumor and positive staining for estrogen receptor, might lead to a misdiagnosis of metastatic breast carcinoma. As the therapeutic implications differ, it is important for the pathologist to critically assess axillary lymph node metastases, even in patients with a past history of ipsilateral breast carcinoma and no other known primary tumors.

Use of immunohistochemistry in the diagnosis of problematic breast lesions

Most diagnoses in breast pathology can be made with H&E sections. Nevertheless immunohistochemistry plays a useful supplementary role. This article reviews the common uses of immunohistochemistry in diagnostic breast pathology. It is important to be aware of the limitations of individual antibodies. Such problems can often be overcome by using panels of antibodies. Quality control is also essential: internal and external controls should show appropriate staining. Immunohistochemistry must be interpreted in combination with the morphology seen on H&E sections. Myoepithelial markers, such as smooth muscle actin, smooth muscle myosin heavy chain and p63, are useful for distinguishing invasive carcinoma from sclerosing lesions and ductal carcinoma in situ (DCIS), and in the classification of papillary lesions. Basal cytokeratins can help distinguish epithelial hyperplasia of usual type (UEH) and clonal proliferations such as DCIS and lobular carcinoma in situ (LCIS). UEH usually shows patchy expression whereas DCIS and other clonal proliferations are typically negative. E-cadherin can usually separate DCIS and LCIS: DCIS typically shows membrane staining and most LCIS is negative. Cytokeratins can be used to detect small nodal metastases or subtle invasive carcinomas such as invasive lobular carcinomas. Immunohistochemistry plays a useful role in diagnosing spindle cell lesions such as a panel of cytokeratins to identify spindle cell carcinomas. Immunohistochemistry is helpful in recognising metastases to the breast. Different antibodies are useful for different tumours: WT1 for ovarian carcinoma; TTF1 for pulmonary adenocarcinoma; S100, melan-A and HMB45 for melanoma; and lymphoid markers for lymphoma.

Non-mammary metastases to the breast and axilla: a study of 85 cases

Non-mammary metastases to the breast and axilla are rare occurrences. However, they are important diagnostic considerations as their treatment and prognosis differ significantly from primary breast cancer. Between 1990 and 2010, we identified a total of 85 patients, 72 women and 13 men, with non-mammary malignancies involving the breast, axilla, or both. The tumor types consisted of carcinoma (58%), melanoma (22%) and sarcoma (20%). Ovary was the most common site of origin for carcinoma, and metastatic high-grade ovarian serous carcinoma was most frequently misdiagnosed as a primary breast carcinoma. Melanoma was the single most common non-carcinomatous tumor type to involve the breast and/or axilla, and uterine leiomyosarcoma was the most common type of sarcoma. Most patients (77%) had other metastases at the time of diagnosis of the tumor, but in 11% the breast or axillary lesion was the first presentation. Without a clinical history, non-mammary metastases were difficult to diagnose because the majority of cases presented with a solitary nodule and lacked pathognomonic pathologic features. There were, however, certain recurrent histological findings identified, such as the often relatively well-circumscribed growth pattern of the metastatic lesion surrounded by a fibrous pseudocapsule, and the absence of an in situ carcinoma. Overall, these patients had poor survival; 96% of patients with follow-up available are dead of disease, with a median survival of 15 months after the diagnosis of the breast or axillary lesion. This finding emphasizes the need to accurately identify these tumors as metastases in order to avoid unnecessary procedures and treatments in these patients.

Value of PAX2 immunostaining in tumor diagnosis: a review and update

PAX2 is a member of the PAX family of transcription factors that, together with PAX8, is involved in the regulation of the organogenesis of the kidney and the Müllerian system. Recent investigations have demonstrated that, among tumors, PAX2 is commonly expressed in epithelial tumors of the kidney and female genital tract. Although PAX2 expression has also been reported in B-cell lymphomas and rhabdomyosarcomas, especially alveolar rhabdomyosarcomas, it has been suggested that the positivity in these tumors was most probably due to a cross-reactivity of the anti-PAX2 antibody used in those investigations with other members of the PAX protein family. An analysis of published studies indicates that PAX2 sensitivity for epithelial renal neoplasms and epithelial tumors of the female genital tract is lower than that of PAX8. In contrast to the latter marker, however, PAX2 does not appear to be expressed in epithelial tumors of the thyroid gland or thymus. Because of its restricted expression, PAX2 has proved to be a useful immunohistochemical marker with a wide range of diagnostic applications in surgical pathology, some of which will be briefly reviewed.

Application of immunohistochemistry in the diagnosis of epithelioid mesothelioma: a review and update

A large number of immunohistochemical markers that can assist in the differential diagnosis of epithelioid mesotheliomas are currently available. Because these markers are expressed differently in the various types of carcinomas that can metastasize to the serosal membranes and can potentially be confused with epithelioid mesothelioma, their selection for inclusion in a diagnostic panel largely depends on the differential diagnosis, as well as on which ones work the best in a given laboratory. Traditionally, the panels used in the differential diagnosis of epithelioid mesothelioma have consisted of a combination of positive mesothelioma markers and broad-spectrum carcinoma markers. At present, a wide variety of organ-associated carcinoma markers such as thyroid transcription factor-1 and napsin A for the lung, PAX 8 and PAX 2 for the kidney, and Müllerian-derived tumors; gross cystic disease fluid protein-15 and mammaglobin for the breast; and CDX2 for intestinal differentiation are available, which can assist in establishing the site of origin of an adenocarcinoma when included in a diagnostic panel. This article provides updated information on the composition of the panels of markers recommended in the various differential diagnoses.

Metastases to and from the Breast

Breast cancer is a common source of systemic metastatic disease. Distinguishing metastatic breast cancer from other types of malignancies can be diagnostically challenging but is important for correct treatment and prognosis. Nonmammary tumors can also metastasize to the breast, although this is a rare phenomenon. Differentiating a metastasis to the breast from a primary breast cancer can likewise be difficult. Knowledge of the clinical history and careful morphologic evaluation are the cornerstones of diagnosis. A panel of immunohistochemical stains tailored to the differential diagnosis at hand can provide helpful information in ambiguous cases.

NY-BR-1 and PAX8 immunoreactivity in breast, gynecologic tract, and other CK7+ carcinomas: potential use for determining site of origin

The distinction between breast and müllerian carcinomas from each other and from tumors with a similar cytokeratin profile can be difficult. We tested the usefulness of 2 new markers, NY-BR-1 and PAX8, by staining a variety of breast and gynecologic carcinomas, along with tumors of pancreas, bile ducts, stomach, and gastroesophageal junction. NY-BR-1 expression (ie, H score >10) was seen in 58.4% of breast carcinomas (111/190), 5.6% of müllerian carcinomas (8/142), 7% of pancreatic tumors (1/15), 0% of cholangiocarcinomas (0/22), 0% of gastric tumors (0/36), and 0% of gastroesophageal carcinomas (0/25). All 188 breast carcinomas were negative for PAX8. PAX8 expression was seen in 72.4% of müllerian tumors (105/145). All pancreatic tumors (n = 15), cholangiocarcinomas (n = 23), and gastric (n = 35) and gastroesophageal junction (n = 25) carcinomas were negative for PAX8. Addition of NY-BR-1 and PAX8 in a panel would be useful in distinguishing breast cancer, gynecologic tumors, and tumors of the upper gastrointestinal tract.

Mucinous carcinoma of the breast is genomically distinct from invasive ductal carcinomas of no special type

Mucinous carcinomas are a rare entity accounting for up to 2% of all breast cancers, which have been shown to display a gene expression profile distinct from that of invasive ductal carcinomas of no special type (IDC-NSTs). Here, we have defined the genomic aberrations that are characteristic of this special type of breast cancer and have investigated whether mucinous carcinomas might constitute a genomic entity distinct from IDC-NSTs. Thirty-five pure and 11 mixed mucinous breast carcinomas were assessed by immunohistochemistry using antibodies against oestrogen receptor (ER), progesterone receptor, HER2, Ki67, cyclin D1, cortactin, Bcl-2, p53, E-cadherin, basal markers, neuroendocrine markers, and WT1. Fifteen pure mucinous carcinomas and 30 grade- and ER-matched IDC-NSTs were microdissected and subjected to high-resolution microarray-based comparative genomic hybridization (aCGH). In addition, the distinct components of seven mixed mucinous carcinomas were microdissected separately and subjected to aCGH. Pure mucinous carcinomas consistently expressed ER (100%), lacked HER2 expression (97.1%), and showed a relatively low level of genetic instability. Unsupervised hierarchical cluster analysis revealed that pure mucinous carcinomas were homogeneous and preferentially clustered together, separately from IDC-NSTs. They less frequently harboured gains of 1q and 16p and losses of 16q and 22q than grade- and ER-matched IDC-NSTs, and no pure mucinous carcinoma displayed concurrent 1q gain and 16q loss, a hallmark genetic feature of low-grade IDC-NSTs. Finally, both components of all but one mixed mucinous carcinoma displayed similar patterns of genetic aberrations and preferentially clustered together with pure mucinous carcinomas on unsupervised clustering analysis. Our results demonstrate that mucinous carcinomas are more homogeneous between themselves at the genetic level than IDC-NSTs. Both components of mixed mucinous tumours are remarkably similar at the molecular level to pure mucinous cancers, suggesting that mixed mucinous carcinomas may be best classified as variants of mucinous cancers rather than of IDC-NSTs.

Cancer-testis antigen expression in triple-negative breast cancer

BACKGROUND

cancer-testis (CT) antigens, frequently expressed in human germline cells but not in somatic tissues, may become aberrantly reexpressed in different cancer types. The aim of this study was to investigate the expression of CT antigens in breast cancer.

PATIENTS AND METHODS

a total of 100 selected invasive breast cancers, including 50 estrogen receptor (ER) positive/HER2 negative and 50 triple negative (TN), were examined for NY-ESO-1 and MAGE-A expression by immunohistochemistry.

RESULTS

a significantly higher expression of MAGE-A and NY-ESO-1 was detected in TN breast cancers compared with ER-positive tumors (P = 0.04). MAGE-A expression was detected in 13 (26%) TN cancers compared with 5 (10%) ER-positive tumors (P = 0.07). NY-ESO-1 expression was confirmed in nine (18%) TN tumor samples compared with two (4%) ER-positive tumors.

CONCLUSIONS

MAGE-A and NY-ESO-1 CT antigens are expressed in a substantial proportion of TN breast cancers. Because of the limited therapeutic options for this group of patients, CT antigen-based vaccines might prove to be useful for patients with this phenotype of breast cancer.

Mucinous Lesions of the Breast

Breast lesions associated with extracellular mucin production are uncommon and constitute a wide spectrum of lesions ranging from benign cyst to mucinous carcinoma. Intracytoplasmic mucin can be seen rarely in benign metaplasias but is a common finding in invasive and in situ carcinomas. In this article, we discuss the differential diagnosis of breast lesions associated with mucin production and other entities that show histologic changes that mimic mucin production.

Immunohistochemical expression of GCIP in breast carcinoma: relationship with tumour grade, disease-free survival, mucinous differentiation and response to chemotherapy

AIMS

Grap2 and cyclin-D interacting protein (GCIP) is a putative tumour suppressor in human cancer. The aim was to investigate its prognostic significance in human breast carcinoma.

METHODS AND RESULTS

Immunohistochemical analysis of breast carcinoma specimens from 107 female patients was performed. Decreased cytoplasmic expression of GCIP was detected in breast carcinomas compared with normal ductal epithelium (P < 0.001). Higher GCIP scores were observed in patients with lower histological grade, mucinous carcinomas and better clinical outcome (P < 0.05). Disease-free survival was significantly longer in patients with high GCIP scores than in those with low GCIP scores (P = 0.010). However, GCIP expression was independent of the status of oestrogen receptor, progesterone receptor, Her-2/neu and cancer stage. Moreover, in patients receiving neoadjuvant chemotherapy, those with higher GCIP scores showed potentially more reduction of tumour size compared with those with lower GCIP scores (borderline significance, P = 0.053).

CONCLUSIONS

The current data provide evidence that decreased expression of GCIP in vivo is present in human breast carcinoma and indicate that GCIP is a potential indicator of good prognosis. In patients receiving neoadjuvant chemotherapy, it may also have predictive value for the chemotherapeutic response.