Expression of TRPS1 in phyllodes tumor and sarcoma of the breast

Classification of Fibroepithelial Lesions of the Breast in Core Needle Biopsy With Implications for Further Management

Fibroepithelial lesions (FELs) of the breast represent a diverse group of biphasic tumors with varying morphologies and clinical behavior. The classification of FELs is mainly based on a constellation of diagnostic criteria, and intralesional heterogeneity is not uncommon. Therefore, reporting FELs in a core needle biopsy (CNB) with limited tissue material can be challenging as not all the features may be represented for assessment. Differentiating a classic fibroadenoma from a well-sampled phyllodes tumor (PT) is generally straightforward. However, cellular fibroadenoma, morphologically heterogeneous benign PT, and myoid hamartoma can overlap histologically. Accurate grading of PT is also challenging on CNB and carries significant management implications. In this article, we provide an overview and propose a pragmatic approach to reporting FELs on CNB, particularly for lesions with overlapping features. Guidance using the UK/European "B" classification of FELs alongside descriptive reporting of the various lesions, is also presented to aid in management decisions.

TRPS1 expression in breast angiosarcoma

Angiosarcoma (AS) of the breast, a rare mesenchymal neoplasm, exhibits distinct forms based on etiological and genetic features. While cases with typical clinical presentation and morphology allow for a straightforward diagnosis, challenges arise when clinical data are scarce, diagnostic material is limited, or morphological characteristics overlap with other tumors, including undifferentiated carcinomas. The trichorhinophalangeal syndrome protein 1 (TRPS1), once regarded as highly specific for breast carcinomas, now faces doubts regarding its reliability. This study explores TRPS1 expression in breast AS. Our investigation revealed that 60% of AS cases displayed TRPS1 labeling, contrasting with the 40% lacking expression. Scoring by four independent readers established a consensus, designating 12/35 ASs as unequivocally TRPS1-positive. However, uncertainty surrounded nine further cases due to a lack of reader agreement (being substantial as reflected by a kappa value of 0.76). These findings challenge the perceived specificity of TRPS1, shedding light on its presence in a noteworthy proportion of breast ASs. Consequently, the study underscores the importance of a comprehensive approach in evaluating breast ASs and expands the range of entities within the differential diagnosis associated with TRPS1 labeling.

Targeted DNA Sequencing in Diagnosis of Malignant Phyllodes Tumors With Emphasis on Tumors With Keratin and p63 Expression

The differential diagnosis of malignant spindle cell neoplasms in the breast most frequently rests between malignant phyllodes tumor (MPT) and metaplastic carcinoma (MBC). Diagnosis of MPT can be challenging due to diffuse stromal overgrowth, keratin (CK) and/or p63 immunopositivity, and absent CD34 expression, which can mimic MBC, especially in core biopsies. Distinction of MPT from MBC has clinical implications, with differences in surgical approach, chemotherapy, and radiation. In this study, we evaluated MPTs (78 tumors, 64 patients) for stromal CK, p63, and CD34 expression and profiled a subset (n = 31) by targeted next-generation DNA sequencing, with comparison to MBC (n = 44). Most MPTs (71%) were CK+ and/or p63+, including 32% CK+ (25/77 focal) and 65% p63+ (32/66 focal, 10/66 patchy, and 1/66 diffuse). Thirty percent of MPTs expressed both CK and p63 (20/66), compared with 95% of MBCs (40/42, P < .001). CK and/or p63 were positive in CD34+ and CD34- MPTs. Recurrent genetic aberrations in MPTs involved TERT, TP53, MED12, CDKN2A, chromatin modifiers, growth factor receptors/ligands, and phosphoinositide-3 kinase (PI-3K) and MAPK pathway genes. Only MED12 (39%, 12/31) and SETD2 (13%, 4/31) were exclusively mutated in MPTs and not MBCs (P < .001 and P = .044, respectively), whereas PIK3R1 mutations were only found in MBCs (37%, 13/35, P < .001). Comparative literature review additionally identified ARID1B, EGFR, FLNA, NRAS, PDGFRB, RAD50, and RARA alterations enriched or exclusively in MPTs vs MBCs. MED12 was mutated in MPTs with diffuse stromal overgrowth (53%, 9/17), CD34- MPTs (41%, 7/17), and CK+ and/or p63+ MPTs (39%, 9/23), including 36% of CD34- MPTs with CK and/or p63 expression. Overall, MED12 mutation and/or CD34 expression were observed in 68% (21/31) MPTs, including 61% (14/23) of CK+ and/or p63+ tumors. Our results emphasize the prevalence of CK and p63 expression in MPTs and demonstrate the diagnostic utility of next-generation DNA sequencing, especially in MPTs with confounding factors that can mimic MBC.

[Borderlines and malignant phyllodes tumors of the breast: From the anatomopathological challenge to the standard of care]

Phyllodes tumors, borderline (BPT) and malignant (MPT), represent a rare group of fibroepithelial breast tumors. Due to their rarity, their treatment remains poorly codified. The precise incidence of these tumors remains unknown. TPMs represent half of breast sarcomas and 1 % of breast tumors. Their treatment at the localized stage is based on surgery, that can be conservative surgery or a mastectomy. The impact of oncoplastic techniques and immediate breast reconstruction is not documented. The excision margins of the BPT and MPT must be free, a wider margin can provide a benefit in local recurrence but in also overall survival in the case of TPM. The optimal width of the excision margin is not known. In the event of positive margins, a second surgery could make up the result of an insufficient first surgery. Chemotherapy does not seem to provide any benefit on recurrence-free survival, but the available data are particularly weak. The data on adjuvant radiotherapy are more important. This allows better local control in the event of breast-conserving surgery. The benefit of post-mastectomy radiotherapy is less documented but can be considered in cases of poor prognostic factors. The management of TPM at the metastatic stage is based on the use of chemotherapy (anthracyclines, Ifosfamide) and local treatment of metastases in cases of oligometastatic disease. Due to the rarity of these tumors, it is essential that their management be discussed within a network of qualified professionals (NETSARC+).

Expression of TRPS1 in Metastatic Tumors of the Skin: An Immunohistochemical Study of 72 Cases

TRPS1 (Tricho-rhino-phalangeal syndrome 1) is a GATA transcriptional activator gene encoding for a protein used as a sensitive immunohistochemical marker of breast carcinomas. In dermatopathology, TRPS1 is used as a marker of mammary and extramammary Paget's disease and is also expressed by a variety of primary cutaneous tumors, mostly of adnexal origin. So far, very limited data exist on the expression of TRPS1 in metastatic skin tumors. We studied the immunohistochemical expression of TRPS1 in 72 cutaneous metastatic tumors from the breast (n: 19) and other origins (n: 53) in order to assess its diagnostic usefulness. The intensity of TRPS1 immunostaining was expressed as a histoscore: the product of the percentage of positive cells (scored semi-quantitatively 0-4) and the staining intensity (scored 0-3). In normal skin, nuclear TRPS1 expression was predominantly observed in cells of adnexal structures (pilosebaceous follicles and sweat glands). Eighteen (18/19, 94.7%) metastatic breast carcinomas showed diffuse and strong TRPS1 positivity (histoscore 12). Lower reactivity was found in some other metastases, including from the lung (11/22), the female genital tract (3/4), and the kidney (2/4), whereas most (20/22) metastases from the digestive system and peritoneum, along with a case of metastatic prostate carcinoma, were negative. These results suggest that a high histoscore for TRPS1 is in favor of the mammary origin of metastatic cutaneous carcinoma. Although TRPS1 is not absolutely specific or sensitive to a particular primary, we consider that it can be added to a panel of other markers when investigating the origin of a cutaneous metastasis, namely when this is the first manifestation of the neoplastic disease.

A Comprehensive Review of TRPS1 as a Diagnostic Immunohistochemical Marker for Primary Breast Carcinoma: Latest Insights and Diagnostic Pitfalls

BACKGROUND/OBJECTIVES

Immunohistochemical expression of TRPS1 (trichorhinophalangeal syndrome type 1) protein is usually used by pathologists to confirm breast origin for triple-negative breast cancers (TNBC) or metastatic carcinomas of unknown primary. However, recent studies have reported TRPS1 expression in a variety of non-breast lesions. This review aims to provide a comprehensive evaluation of TRPS1 expression across various tumor types, highlighting both its diagnostic utility and potential pitfalls that may arise in clinical practice.

METHODS

A thorough search of the PubMed database on TRPS1 immunoexpression in tumor pathology was conducted. While the gene itself has been known for several decades, most studies regarding its use in immunohistochemistry emerged in the late 2010s. Particular emphasis was placed on case reports and cohort studies that examined the implications of TRPS1 expression in non-breast tissues, as well as variations in the results between commercially available TRPS1 clones, which may influence the staining intensity and specificity.

RESULTS

TRPS1 demonstrated a strong diagnostic utility in identifying primary breast lesions, particularly in TNBC cases. However, its expression in a growing number of non-breast cancers, such as lung adenocarcinoma, prostate adenocarcinoma, urothelial carcinoma, ovarian high-grade serous carcinoma, and endometrial adenocarcinoma, as well as up to 96% of synovial sarcomas with SS18-SSX fusion, emphasizes the need for caution when interpreting TRPS1 positivity and suggests a multi-marker approach in order to increase the diagnostic accuracy.

CONCLUSIONS

While TRPS1 remains a highly sensible immunohistochemical marker for confirming breast primary lesions, pathologists should be aware of its low specificity and incorporate complementary diagnostic methods in order to ensure accurate clinical management. Further research should focus on elucidating the molecular pathways regulating TRPS1 expression in various tumor types, which may better define its clinical utility.

TRPS1 expression in MPNST is correlated with PRC2 inactivation and loss of H3K27me3

Initially described as a highly specific immunohistochemical marker for carcinomas of mammary origin, trichorhinophalangeal syndrome type 1 (TRPS1) has subsequently been detected in a variety of other non-mammary tumors. In this study, we examined the immunohistochemical expression of TRPS1 in 114 peripheral nerve sheath tumors, including 43 malignant peripheral nerve sheath tumors (MPNSTs), 58 schwannomas, including 9 cellular neurofibromas, and 13 neurofibromas, including 1 atypical neurofibroma. Notably, TRPS1 was expressed in 49% of MPNSTs and was absent in all schwannomas and neurofibromas. All MPNSTs showed TRPS1 labeling in >50% of nuclei, with 95% of cases demonstrating diffuse labeling. Most cases (67%) showed weak TRPS1 immunoreactivity, while a smaller subset showed moderate (24%) or strong (9%) intensity staining. Analysis of publicly available gene expression datasets revealed higher levels of TRPS1 mRNA in MPNSTs with PRC2 inactivation. In keeping with this finding, TRPS1 expression was more commonly observed in MPNSTs with loss of H3K27me3, suggesting a potential relationship between TRPS1 and the PRC2 complex. This study further broadens the spectrum of TRPS1-expressing tumors to include MPNST.

Malignant phyllodes tumor of the breast with predominant osteosarcoma and chondrosarcomatous differentiation: a rare case report and review of literature

Background

Phyllodes tumors (PTs), which account for less than 1% of mammary gland tumors, composed of both epithelial and stromal components. If a malignant heterologous component is encountered, PT is considered malignant. Malignant phyllodes tumors (MPTs) only account for 8% to 20% of PTs. We report a case of MPT with osteosarcoma and chondrosarcoma differentiation and review the literature to discuss the differential diagnosis and therapy.

Case presentation

A 59-year-old Chinese woman come to our hospital because of a palpable mass she had had for 1 months in the left breast. Preoperative core needle biopsy (CNB) was performed on the left breast mass on January 11, 2023. Pathological diagnosis was malignant tumor, the specific type was not clear. Mastectomy and sentinel lymph node biopsy of the left breast was performed. No metastasis was found in 3 sentinel lymph nodes identified by carbon nanoparticles and methylene blue double staining. Heterologous osteosarcoma and chondrosarcomatous differentiation of phyllodes tumor were observed. Immunohistochemistry: spindle tumor cells ER(-), PR(-), HER-2(-), CK-pan(-), CK7(-), CK8(-), SOX10(-), S100(-), and MDM2(-), CK5/6(-), P63(-), P40(-) were all negative. CD34:(+), SATB2(+), P53(90% strong), CD68 (+), Ki-67(LI: about 60%). No ductal carcinoma in situ was found in the breast. Fluorescence in situ hybridization (FISH) indicated USP6 was negatively expressed on formalin-fixed, paraffin-embedded (FFPE) tissue sections.

Conclusion

MPTs are rare, and heterologous differentiation in MPTs is exceedingly rare. It could be diagnosed by pathology when metaplastic carcinoma, primary osteosarcoma, or myositis ossificans were excluded. This case could help clinicians to improve the prognosis and treatment of this disease.

Translational Aspects in Metaplastic Breast Carcinoma

Breast cancer is the most common cancer among women. Metaplastic breast carcinoma (MpBC) is a rare, heterogeneous group of invasive breast carcinomas, which are classified as predominantly triple-negative breast carcinomas (TNBCs; HR-negative/HER2-negative). Histologically, MpBC is classified into six subtypes. Two of these are considered low-grade and the others are high-grade. MpBCs seem to be more aggressive, less responsive to neoadjuvant chemotherapy, and have higher rates of chemoresistance than other TNBCs. MpBCs have a lower survival rate than expected for TNBCs. MpBC treatment represents a challenge, leading to a thorough exploration of the tumor immune microenvironment, which has recently opened the possibility of new therapeutic strategies. The epithelial-mesenchymal transition in MpBC is characterized by the loss of intercellular adhesion, downregulation of epithelial markers, underexpression of genes with biological epithelial functions, upregulation of mesenchymal markers, overexpression of genes with biological mesenchymal functions, acquisition of fibroblast-like (spindle) morphology, cytoskeleton reorganization, increased motility, invasiveness, and metastatic capabilities. This article reviews and summarizes the current knowledge and translational aspects of MpBC.

TRPS1 expression in non-melanocytic cutaneous neoplasms: an immunohistochemical analysis of 200 cases

BACKGROUND

Although trichorhinophalangeal syndrome type 1 (TRPS1) was initially thought to be highly sensitive and specific for carcinomas and mesenchymal tumors of mammary origin, more recent data suggest its expression is not limited to breast neoplasms but also can be seen in other cutaneous neoplasms, such as extramammary Paget disease and squamous cell carcinoma (SCC) in situ.

METHODS

Two-hundred cases of non-melanocytic cutaneous neoplasm, including basal cell carcinomas (BCCs) (n = 41), SCCs (n = 35), Merkel cell carcinomas (MCCs) (n = 25), and adnexal neoplasms (n = 99), were tested for TRPS1 expression using a monoclonal anti- TRPS1 rabbit anti-human antibody.

RESULTS

TRPS1 expression was present in almost all cases of SCC (94%), with a median H-score of 200, while it was either absent or only focally present in most BCCs (90%), with a median H-score of 5. The difference between BCCs and SCCs in H-score was significant (p < .001). All MCCs (100%) lacked TRPS1 expression. TRPS1 expression was frequently seen in most adnexal neoplasms, benign and malignant, in variable intensity and proportion but was consistently absent in apocrine carcinomas. All endocrine mucin-producing sweat gland carcinomas (EMPSGCs) (100%, 6/6) showed diffuse and strong TRPS1 immunoreactivity, with a median H-score of 300, which was significantly different (p < .001) than that of BCCs.

CONCLUSIONS

Our study shows that TRPS1 may be an effective discriminatory marker for BCCs and SCCs. It also has a role in distinguishing BCCs from EMPSGCs.

A Comparative Evaluation of TRPS1 and GATA3 in adenoid cystic, secretory, and acinic cell carcinomas of the breast and salivary gland

GATA3 is the most used marker to determine tumors' breast origin, but its diagnostic value in triple-negative breast cancer (TNBC) is limited. The newly identified TRPS1 is highly sensitive and specific for breast carcinoma, especially TNBC. Here, we compared the utility of TRPS1 and GATA3 expression in a subset of salivary gland-type breast tumors (including adenoid cystic, acinic cell, and secretory carcinomas [AdCC, ACC, and SC, respectively]), and we compared TRPS1 and GATA3 expression of such tumors with head and neck (H&N) and AdCC of upper respiratory tumors. TRPS1 was strongly expressed in basaloid TNBC and AdCCs with solid components, including 100 % of mixed and solid breast AdCCs. However, TRPS1 was positive in only 50 % cribriform AdCCs. Expression patterns of TRPS1 in H&N and upper respiratory AdCC were similar. TRPS1 was positive in 30 % of H&N cribriform AdCCs but was strongly expressed in mixed AdCC (67 %) and solid AdCC (100 %). In the upper respiratory AdCCs, TRPS1 was positive in 58.4 % of cribriform AdCCs and positive in 100 % of AdCCs with solid components. On the contrary, GATA3 was negative in predominant AdCCs of the breast, H&N, and upper respiratory tract. These data show that GATA3 and TRPS1 expression varies AdCCs. In addition, TRPS1 and GATA3 expression patterns were similar SC and ACC of breast and H&N. Both markers were positive in SC and negative in ACC. Therefore, TRPS1 and GATA3 cannot be used to differentiate salivary gland-type carcinomas of breast origin from those of upper respiratory or H&N origin.

TRPS1 and GATA3 Expression in Invasive Breast Carcinoma With Apocrine Differentiation

CONTEXT.—

The recently identified immunohistochemical marker TRPS1 is highly sensitive and specific for invasive breast carcinoma, especially triple-negative breast carcinoma. However, TRPS1 expression in special morphologic subtypes of breast cancer is unclear.

OBJECTIVE.—

To investigate the expression of TRPS1 in invasive breast cancer with apocrine differentiation, in comparison to the expression of GATA3.

DESIGN.—

A total of 52 invasive breast carcinomas with apocrine differentiation, comprising 41 triple-negative breast carcinomas and 11 estrogen receptor (ER) and progesterone receptor (PR)-negative, human epidermal growth factor receptor 2 (HER2)-positive cases, along with 11 triple-negative breast carcinomas without apocrine differentiation, were evaluated for TRPS1 and GATA3 expression by immunohistochemistry. All tumors were diffusely positive (>90%) for androgen receptor (AR).

RESULTS.—

Triple-negative breast carcinoma with apocrine differentiation had positive TRPS1 expression in 12% of cases (5 of 41), whereas GATA3 was positive in all cases. Similarly, HER2+/ER- invasive breast carcinoma with apocrine differentiation showed positive TRPS1 in 18% of cases (2 of 11), whereas GATA3 was positive in all cases. In contrast, triple-negative breast carcinoma with strong AR expression but without apocrine differentiation showed both TRPS1 and GATA3 expression in 100% (11 of 11) of cases.

CONCLUSIONS.—

Most ER-/PR-/AR+ invasive breast carcinomas with apocrine differentiation are TRPS1 negative and GATA3 positive, regardless of HER2 status. Therefore, TRPS1 negativity does not exclude breast origin in tumors with apocrine differentiation. A panel of TRPS1 and GATA3 immunostains can be helpful when the tissue origin of such tumors is clinically relevant.

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.

Updates in the Use of Immunohistochemical Stains in Breast and Gynecologic Pathology

CONTEXT.—

The use of immunohistochemical stains in breast and gynecologic pathology has become increasingly complex, with various diagnostic, prognostic, and predictive applications.

OBJECTIVE.—

To provide an update and review of immunohistochemical stains used in the practice of breast and gynecologic pathology. Established and new entities are reviewed, with descriptions of histomorphology and immunohistochemical staining patterns and discussion of interpretive pitfalls.

DATA SOURCES.—

Data were obtained from review of the English-language literature and firsthand experience of the authors in breast and gynecologic pathology.

CONCLUSIONS.—

Many entities in breast and gynecologic pathology benefit from evaluation with various immunohistochemical stains. These studies not only aid in the diagnosis and staging of tumors but also can provide prognostic and predictive information. Updated guidelines for recommended ancillary studies such as mismatch repair, p53, and human epidermal growth factor receptor 2 (HER2) studies in endometrium, as well as estrogen and progesterone receptors and HER2 in breast, are discussed. Finally, the use and interpretation of established and novel immunohistochemical stains are discussed in various breast and gynecologic malignancies.

TRPS1 expression in primary and secondary extramammary Paget diseases: An immunohistochemical analysis of 93 cases

Extramammary Paget disease (EMPD) predominantly manifests de novo as primary EMPD, with less than 30 % of cases associated with underlying internal malignancy (secondary EMPD). Differentiating primary from secondary EMPDs based solely on histopathology poses challenges, often necessitating supplementary screening, such as endoscopy or imaging studies, to definitively exclude underlying carcinomas like colonic adenocarcinoma. Recently, TRPS1 immunohistochemistry, initially identified as a sensitive and specific marker for carcinomas and mesenchymal tumors of mammary origin, has been proposed for EMPD. In this study, we conducted a systematic assessment of TRPS1 expression across 93 EMPD cases, comprising 82 primary EMPDs and 11 secondary EMPDs. Our aim was to assess the potential utility of TRPS1 as a marker to differentiate between primary and secondary EMPDs. Our findings revealed that 88 % (72/82) of primary EMPDs displayed TRPS1 expression, while secondary EMPDs consistently lacked TRPS1 expression (100 %; 11/11). Within the primary EMPD group, consistent TRPS1 immunoreactivity was observed in lesions originating outside the perianal region, such as the groin/inguinal area, axilla, and trunk. Interestingly, a majority (91 %; 10/11) of primary EMPDs originating in the perianal region exhibited an absence of TRPS1 expression. Upon excluding cases of perianal primary EMPDs, the sensitivity and specificity of TRPS1 for primary EMPDs reached 100 %. Our findings suggest that TRPS1 expression holds notable sensitivity and specificity for primary EMPDs, particularly when arising from non-perianal cutaneous sites. Hence, in suitable clinical contexts, TRPS1 immunohistochemistry may emerge as a promising and valuable tool for distinguishing primary and secondary EMPDs.

TRPS1, a New Promising Marker for Assessment of Distant Metastatic Breast Cancer

This article reviewed the identification of breast cancer in the distant metastatic setting through traditional immunohistochemical markers, such as mammaglobin and GATA3, compared with the novel immunohistochemical stain, Trichorhinophalangeal syndrome-1 (TRPS1). We review previous studies evaluating TRPS1 staining, which were conducted using cytology specimens, as well as our recently conducted study evaluating this stain using surgical tissue samples, both from primary and distant metastatic invasive breast carcinoma. In summary, although no immunohistochemical stain is 100% specific or sensitive, in the metastatic setting where tissue available for ancillary studies is limited, TRPS1 was a reliable and even a standalone marker for breast origin, particularly in cases of triple-negative breast cancer.

Utility of TRPS1 immunohistochemistry in confirming breast carcinoma: Emphasis on staining in triple-negative breast cancers and gynecologic tumors

OBJECTIVES

Our aim was to explore the performance of TRPS1 as an immunohistochemical diagnostic marker; find the optimal conditions for its use in breast carcinomas, especially triple-negative breast cancers (TNBCs); and compare its results in carcinomas of a select few organ sites, with an emphasis on gynecologic tumors.

METHODS

Tissue microarrays from breast carcinomas (n = 197), endometrial adenocarcinomas (n = 69), ovarian tumors (n = 250), vulvar squamous cell carcinomas (n = 97), pancreatic ductal adenocarcinomas (n = 20), and gastric adenocarcinomas (n = 12) were stained with TRPS1 using 2 different conditions (protocol 1: high pH; protocol 2: low pH). Breast carcinomas consisted of hormone receptor (HR)-positive/ERBB2 (formerly HER2 or HER2/neu)-negative (n = 53) samples, HR-positive/ERBB2-positive (n = 6) samples, and TNBCs (n = 138).

RESULTS

Comparing TRPS1 results in breast carcinomas vs tumors from other organ sites, the sensitivity of TRPS1 was 91% and 87%, respectively, while the specificity was 66% and 74% for protocol 1 and 2, respectively. For TNBCs vs gynecologic tumors, the sensitivity of TRPS1 was 89% and 85%, respectively, while the specificity was 65% and 73%, respectively.

CONCLUSIONS

TRPS1 stains approximately 90% of breast carcinomas but also up to 71% of endometrial carcinomas, albeit with a weaker median expression. Our data show that although TRPS1 is a highly sensitive marker for TNBCs, it is not as highly specific as previously reported.

Immunohistochemistry in the Diagnosis and Classification of Breast Tumors

CONTEXT.—

In the clinical practice of breast pathology, immunohistochemistry (IHC) of different markers is widely used for the diagnosis and classification of breast lesions.

OBJECTIVE.—

To provide an overview of currently used and recently identified IHC stains that have been implemented in the field of diagnostic breast pathology.

DATA SOURCES.—

Data were obtained from literature review and clinical experience of the authors as breast pathologists.

CONCLUSIONS.—

In the current review, we summarize the common uses of IHC stains for diagnosing different types of breast lesions, especially invasive and noninvasive breast lesions, and benign and malignant spindle cell lesions. In addition, the cutting-edge knowledge of diagnostic carcinoma markers will lead us to further understand the different types of breast carcinoma and differentiate breast carcinomas from other carcinomas of similar morphology. Knowing the strengths and limitations of these markers is essential to the clinical practice of breast pathology.

Trichorhinophalangeal syndrome type 1 (TRPS1) expression in male breast carcinoma

Currently, there is a paucity of highly specific and sensitive markers to identify breast carcinoma in male patients. Immunohistochemical stains commonly used for unmasking primary breast carcinomas include estrogen receptor (ER) and GATA3. However, these markers are commonly expressed in carcinomas originating from other organ systems and can be reduced in breast carcinomas with higher histologic grades. Androgen receptor (AR) may be used to highlight primary male breast cancer, but this marker can also be expressed in other carcinomas. We evaluated TRPS1, a highly sensitive and specific marker for female breast carcinoma, in cases of male breast carcinoma. Through an institutional database search, we identified 72 cases of primary invasive breast carcinoma in male patients. Among ER/progesterone receptor (PR)-positive cancers, 97% showed intermediate or high positivity for both TRPS1 and GATA3. Among HER2-positive cancers, 100% showed intermediate or high positivity for TRPS1 and GATA3. One case of triple-negative breast cancer was collected, showing high positivity for TRPS1 and negativity for GATA3. AR staining was non-specific and heterogeneous: 76% showed high positivity, but the remaining 24% showed low or intermediate positivity. Additionally, among 29 cases of metastatic carcinoma to male breast tissue, 93% were negative for TRPS1, and the remaining 2 cases (7%), which were carcinomas from salivary gland primary tumors, were intermediate positive. TRPS1 is a sensitive and specific marker in the unmasking of male primary invasive breast carcinoma across different subtypes. Additionally, TRPS1 is not expressed in metastatic carcinomas of multiple primaries, with the exception of salivary gland primaries.

Immunohistochemical expression of TRPS1 in mammary Paget disease, extramammary Paget disease, and their close histopathologic mimics

BACKGROUND

Trichorhinophalangeal syndrome type 1 (TPRS1) expression has been found to be highly sensitive and specific for breast carcinomas. The frequency of TRPS1 expression in cutaneous neoplasms such as mammary Paget disease (MPD) and extramammary PD (EMPD) is currently unknown. We assessed the utility of TRPS1 immunohistochemistry (IHC) in the evaluation of MPD, EMPD, and their histopathologic mimics, squamous cell carcinoma in situ (SCCIS) and melanoma in situ (MIS).

METHODS

Twenty-four MPDs, 19 EMPDs, 13 SCCISs, and 9 MISs were subjected to immunohistochemical analysis using anti-TRPS1 antibody. The intensity (none, 0; weak, 1⁺ ; moderate, 2⁺ ; strong, 3⁺ ) and proportion (<1%, absent; 1%-25%, focal; 26%-75%, patchy; >75%, diffuse) of TRPS1 expression were recorded. Relevant clinical data were documented.

RESULTS

TPRS1 expression was present in 100% (24/24) of MPDs, with 88% (21/24) of MPDs exhibiting strong, diffuse immunoreactivity. Sixty-eight percent (13/19) of EMPDs showed TRPS1 expression. Intriguingly, EMPDs lacking TRPS1 expression were consistently of perianal origin. TRPS1 expression was seen in 92% (12/13) of SCCISs but was absent in all MISs.

CONCLUSIONS

TRPS1 may be useful to distinguish MPDs/EMPDs from MISs, but its utility is limited in distinguishing them from other pagetoid intraepidermal neoplasms such as SCCISs.

Wnt Family Member 9b (Wnt9b) Is a Sensitive and Specific Marker for Triple-negative Breast Carcinoma Including Metaplastic Carcinoma

Wnt9b was recently identified as a highly sensitive and specific marker for breast carcinomas. Due to the limited number of triple-negative breast carcinomas (TNBCs) in previous study, we further explored Wnt9b's utility in breast carcinoma, especially in TNBCs including metaplastic carcinomas. We systematically evaluated Wnt9b expression on tissue microarrays (TMAs) from 413 breast carcinomas, 208 urothelial carcinomas, 102 endometrial carcinomas, 109 cholangiocarcinomas, 192 ovarian carcinomas, 48 lung adenocarcinomas, 69 colorectal adenocarcinomas, and 78 melanomas, and whole tissue section (WTS) from 20 human epidermal growth factor receptor 2-positive, 34 nonmetaplastic TNBCs, and 67 invasive metaplastic carcinomas. The results showed Wnt9b was highly expressed in breast carcinomas (91% on TMA and 98% on WTS) and in nonmetaplastic TNBCs (91% on TMA and 97% on WTS), but almost completely negative in other tested tumor types. Wnt9b was also highly expressed in metaplastic carcinomas (80%), significantly higher than GATA3 (56%) and SOX10 (48%), but slightly lower than TRPS1 (90%). In summary, our results demonstrate that Wnt9b is a highly sensitive marker for breast carcinomas, including TNBCs and metaplastic carcinomas. Further, we compared its utility with other breast markers including TRPS1, GATA3, and SOX10 in metaplastic carcinomas.

Trichorhinophalangeal Syndrome Type 1-Positive Cells in Breast Dermal Granulation Tissues and Scars: A Potential Diagnostic Pitfall

ABSTRACT

Trichorhinophalangeal syndrome type 1 (TRPS1) immunohistochemistry has been gaining popularity in recent years in the field of surgical pathology for its utility as a highly sensitive and specific marker for breast carcinomas, including those with triple-negative phenotype. More recent data suggest TRPS1 may also prove its utility in the diagnosis of mesenchymal tumors arising in the breast parenchyma, including malignant phyllodes tumors and primary chondrosarcomas and osteosarcomas of the breast. However, little is known about TRPS1 expression in nontumor cells, such as stromal fibroblasts/myofibroblasts of dermal granulation tissues and scars. Here, we describe our unique experience with TRPS1-positive cells, morphologically consistent with reactive fibroblasts/myofibroblasts, seen in dermal granulation tissues and scars from breast skin specimens of a 51-year-old woman with a history of bilateral invasive ductal carcinomas of the breast, status after bilateral total mastectomy and chemoradiation, who presented with nonhealing wounds on the chests. To the best of our knowledge, this is the first reported case of strong TRPS1 expression in dermal granulation tissue/scar. As the usage of TRPS1 immunohistochemistry in routine clinical practice, including in the field of dermatopathology, will likely increase over time, awareness of this potential diagnostic pitfall is important to avoid overinterpretation of the findings.

A pilot study: Comparison of TRPS1 and GATA3 immunoperoxidase staining using cytologic smears in entities reportedly positive for GATA3

BACKGROUND

Metastatic breast carcinoma (mBC) is frequently encountered and may be challenging to diagnose as the tumor cells can morphologically resemble carcinomas of other primary origins. An additional challenge is that direct smears are often the only sample type available for immunostaining studies in cytology. Trichorhinophalangeal syndrome GATA-binding type 1 1 (TRPS1) is a highly sensitive marker for BC compared to the commonly used marker GATA3, especially in triple-negative BC (TNBC), in histologic samples. However, its sensitivity and specificity in mBC and other GATA3-positive tumors have not been studied.

METHODS

The authors identified the following cytology cases: 37 GATA3-positive mBC cases and 19 available cases that were deemed mBC but were GATA3-negative during the original case workup and five cases of each of eight epithelioid entities known to have high rates of GATA3 positivity and commonly seen in cytology practice. Immunostainings of TRPS1 and GATA3 were performed on the chosen smears following standard protocols.

RESULTS

TRPS1 was positive in all 37 GATA3-positive mBC cases and in 18 of the 19 GATA3-negative mBC cases. TRPS1 was negative in all five of the seven frequently GATA3-positive epithelioid entities, with the exception of salivary duct carcinomas where GATA3 was positive in a rate ranging 60%-100% among them.

CONCLUSIONS

TRPS1 is as sensitive as GATA3 in GATA3-positive mBC and is more sensitive than GATA3 in TNBC. TRPS1 is negative in most GATA3-positive nonbreast tumors. Thus, the combination of TRPS1 and GATA3 could be used to differentiate breast primary from others in most situations.

Frequent TRPS1 expression in synovial sarcoma is associated with SS18-SSX fusion oncoprotein activity

Synovial sarcoma is an aggressive translocation-associated soft tissue tumor driven by an SS18-SSX fusion oncoprotein. TRPS1 is a recently identified marker for breast carcinoma, but less is known about its expression in other tumor types. We encountered a case of synovial sarcoma showing strong and diffuse expression of TRPS1. To better characterize this observation, we examined the immunohistochemical expression of TRPS1 in 165 cases of synovial sarcoma, including 70 primary, 21 recurrent, and 74 metastatic tumors, using tissue microarrays. TRPS1 expression was observed in 86% of cases. Among the positive cases, TRPS1 labeled >50% of tumor cells in 57% of cases, and staining intensity was strong or moderate in 68%. Metastatic tumors more frequently demonstrated strong and diffuse TRPS1 expression compared to primary tumors. To understand the mechanism of TRPS1 expression, we interrogated publicly available gene expression and ChIP-seq datasets and found that TRPS1 transcript levels are increased in synovial sarcoma compared to other soft tissue sarcomas. Data from ChIP-seq experiments showed enrichment of SS18-SSX protein at the TRPS1 locus and co-localization with RNA pol II. The TRPS1 locus is also enriched in several histone modifications associated with active transcription. In functional knockdown data, repression of SS18::SSX in synovial sarcoma cell lines is associated with reduced TRPS1 transcript levels, further supporting a model whereby TRPS1 expression is mediated, at least in part, by the SS18-SSX fusion oncoprotein. Knowledge of TRPS1 expression in synovial sarcoma may help avoid potential diagnostic pitfalls in the immunohistochemical workup of tumors.

Utility of TRPS-1 immunohistochemistry in diagnosis of metastatic breast carcinoma in cytology specimens

INTRODUCTION

At present, GATA binding protein 3 (GATA-3) is the most frequently used diagnostic immunohistochemical (IHC) marker for breast carcinoma (BC). However, it is not specific and has very low sensitivity for triple-negative BC (TNBC). SRY-box transcription factor 10 (SOX-10) and trichorhinophalangeal syndrome type 1 (TRPS-1) have been suggested for inclusion in the diagnostic workup of TNBC. TRPS-1 has not been established in cytology specimens as a diagnostic IHC marker for metastatic BC (MBC). Hence, in the present study we evaluated the utility of TRPS-1 in diagnosing MBC in cytology specimens.

MATERIALS AND METHODS

MBC cases diagnosed on cytology specimens from January to October 2020 were included in the present study. Only cases with hormonal status available and ≥20 tumor cells on cell blocks were included in the study. The cell blocks were assessed for TRPS-1, GATA-3, and SOX-10 IHC marker positivity (intensity and percentage of tumor cells). The results were correlated with the specimen type (fine needle aspiration [FNA] versus body fluid) and various BC prognostic subgroups.

RESULTS

We analyzed 61 cases, including 33 body fluid and 28 FNA (13 lymph node, 10 bone, 2 liver, 2 soft tissue, and 1 lung) specimens. TRPS-1 had 97.2% positivity in ER/PR+ (estrogen receptor/progesterone receptor-positive) MBC compared with GATA-3, which had 100% positivity in the same group. TRPS-1 showed high positivity in 35 of 37 cases (94.6%) and intermediate positivity in 1 (2.6%) and was negative/low positive in 1 case (2.7%). In contrast, GATA-3 showed high positivity for all 37 cases (100%). SOX-10 showed positivity in only 1 of 37 cases (2.7%), with intermediate positivity. In the HER2+ (human epidermal growth factor receptor 2-positive) group, TRPS-1 showed high positivity in 5 of 7 cases (71.4%), intermediate positivity in 1 case (14.3%), and negativity in 1 case (14.3%). However, GATA-3 showed high positivity in 6 of 7 cases (85.7%) and negative/low positivity in 1 case (14.3%). SOX-10 was negative in all 7 cases. In TNBC, TRPS-1 showed high positivity in 16 of 17 cases (94%) and intermediate positivity in 1 (5.9%), and GATA-3 showed high positivity in 9 (53%), intermediate positivity in 2 (11.8%), and low positive/negative in 6 of the 17 cases (35.3%). TRPS-1 expression was significantly higher than GATA-3 expression for the number of positive cases (P = 0.07), mean percentage of positive tumor cells (P = 0.005), and intensity of reactivity (P = 0.005). SOX-10 expression was present in only 5 of 17 cases (29%), with a mean percentage of positivity in the tumor cells of 26.5% and intensity of 0.8. No differences were found in the IHC results between the different specimen types (FNA versus fluid) in any group.

CONCLUSIONS

TRPS-1 is a highly sensitive new diagnostic IHC marker for breast carcinoma, with a similar positivity rate in ER/PR+ and HER2+ BC compared with GATA-3 and a higher positivity rate than GATA-3 and SOX-10 in TNBC in cytology specimens. In particular, when only a few clusters of tumor cells are present on the cell block, TRPS-1 can be highly useful, because its mean percentage of positive tumor cells and intensity are higher than those of other IHC markers.

Functional mechanisms of TRPS1 in disease progression and its potential role in personalized medicine

The gene of transcriptional repressor GATA binding 1 (TRPS1), as an atypical GATA transcription factor, has received considerable attention in a plethora of physiological and pathological processes, and may become a promising biomarker for targeted therapies in diseases and tumors. However, there still lacks a comprehensive exploration of its functions and promising clinical applications. Herein, relevant researches published in English from 2000 to 2022 were retrieved from PubMed, Google Scholar and MEDLINE, concerning the roles of TRPS1 in organ differentiation and tumorigenesis. This systematic review predominantly focused on summarizing the structural characteristics and biological mechanisms of TRPS1, its involvement in tricho-rhino-phalangeal syndrome (TRPS), its participation in the development of multiple tissues, the recent advances of its vital features in metabolic disorders as well as malignant tumors, in order to prospect its potential applications in disease detection and cancer targeted therapy. From the clinical perspective, the deeply and thoroughly understanding of the complicated context-dependent and cell-lineage-specific mechanisms of TRPS1 would not only gain novel insights into the complex etiology of diseases, but also provide the fundamental basis for the development of therapeutic drugs targeting both TRPS1 and its critical cofactors, which would facilitate individualized treatment.

Matrix Gla protein (MGP), GATA3, and TRPS1: a novel diagnostic panel to determine breast origin

Background

Metastatic breast carcinoma is commonly considered during differential diagnosis when metastatic disease is detected in females. In addition to the tumor morphology and documented clinical history, sensitive and specific immunohistochemical (IHC) markers such as GCDFP-15, mammaglobin, and GATA3 are helpful for determining breast origin. However, these markers are reported to show lower sensitivity in certain subtypes, such as triple-negative breast cancer (TNBC).

Materials and methods

Using bioinformatics analyses, we identified a potential diagnostic panel to determine breast origin: matrix Gla protein (MGP), transcriptional repressor GATA binding 1 (TRPS1), and GATA-binding protein 3 (GATA3). We compared MGP, TRPS1, and GATA3 expression in different subtypes of breast carcinoma of (n = 1201) using IHC. As a newly identified marker, MGP expression was also evaluated in solid tumors (n = 2384) and normal tissues (n = 1351) from different organs.

Results

MGP and TRPS1 had comparable positive expression in HER2-positive (91.2% vs. 92.0%, p = 0.79) and TNBC subtypes (87.3% vs. 91.2%, p = 0.18). GATA3 expression was lower than MGP (p < 0.001) or TRPS1 (p < 0.001), especially in HER2-positive (77.0%, p < 0.001) and TNBC (43.3%, p < 0.001) subtypes. TRPS1 had the highest positivity rate (97.9%) in metaplastic TNBCs, followed by MGP (88.6%), while only 47.1% of metaplastic TNBCs were positive for GATA3. When using MGP, GATA3, and TRPS1 as a novel IHC panel, 93.0% of breast carcinomas were positive for at least two markers, and only 9 cases were negative for all three markers. MGP was detected in 36 cases (3.0%) that were negative for both GATA3 and TRPS1. MGP showed mild-to-moderate positive expression in normal hepatocytes, renal tubules, as well as 31.1% (99/318) of hepatocellular carcinomas. Rare cases (0.6–5%) had focal MGP expression in renal, ovarian, lung, urothelial, and cholangiocarcinomas.

Conclusions

Our findings suggest that MGP is a newly identified sensitive IHC marker to support breast origin. MGP, TRPS1, and GATA3 could be applied as a reliable diagnostic panel to determine breast origin in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-022-01569-1.