Cutaneous and mammary apocrine carcinomas have different immunoprofiles

A review of cutaneous apocrine carcinoma: epidemiology, diagnosis, prognosis, and treatment options

Cutaneous apocrine carcinoma is a rare skin cancer arising from apocrine sweat glands. Disease-specific treatments are required for cutaneous adnexal carcinomas due to their heterogeneous treatment responsiveness. This review reports on the epidemiology, diagnosis, pathological features, surgical management, and use of systemic therapies for cutaneous apocrine carcinoma. Diagnosing cutaneous apocrine carcinoma requires presenting with distinctive pathological features and excluding metastatic adenocarcinomas, particularly breast cancer. Clinical findings are essential to exclude metastatic adenocarcinomas, and immunohistochemistry can be used as an adjunctive tool to rule out other diseases. Wide local excision is the standard treatment for resectable cutaneous apocrine carcinomas. Prophylactic lymphadenectomy should be considered as a treatment option given the high incidence of lymph node metastasis. Generally, cutaneous apocrine carcinomas are resistant to chemotherapy and radiation therapy; however, adjuvant radiotherapy is recommended for high-risk patients. Radiation or systemic therapy is administered to patients with distant metastases or recurrence. The systemic therapeutic options include cytotoxic chemotherapy, hormonal therapy, targeted therapy, and immune checkpoint inhibitors. Given the lack of data on clinical prognosis and standardized treatments, further studies are needed to improve our understanding of cutaneous apocrine carcinomas.

Treatment of HER2-positive cutaneous apocrine carcinoma of the axilla

Cutaneous apocrine carcinoma (CAC) is an extremely rare skin appendage malignant tumor that develops in the apocrine sweat glands, and no evidence-based drug therapy has been established. A 61-year-old female patient was diagnosed with axillary CAC with axillary lymph node metastasis and underwent surgery. Pathological examination revealed seven lymph node metastases. Immunostaining revealed that the tumor cells were estrogen receptor (ER)-positive, progesterone receptor (PgR)-positive, and human epidermal growth factor receptor 2 (HER2)-positive. The patient received chemotherapy, including anti-HER2 drugs, and hormone therapy to prevent recurrence. No recurrence was observed for > 3 years after surgery. The apocrine glands in the skin and mammary glands have similar characteristics and mammary glands are thought to be modified or derived from the apocrine glands present in the subcutaneous adipose tissue. Therefore, ER, PgR, and HER2 levels may be positive in CAC. Drug treatments for breast cancer may also be effective for CAC.

Lipid droplets provide metabolic flexibility for cancer progression

A hallmark of cancer cells is their remarkable ability to efficiently adapt to favorable and hostile environments. Due to a unique metabolic flexibility, tumor cells can grow even in the absence of extracellular nutrients or in stressful scenarios. To achieve this, cancer cells need large amounts of lipids to build membranes, synthesize lipid-derived molecules, and generate metabolic energy in the absence of other nutrients. Tumor cells potentiate strategies to obtain lipids from other cells, metabolic pathways to synthesize new lipids, and mechanisms for efficient storage, mobilization, and utilization of these lipids. Lipid droplets (LDs) are the organelles that collect and supply lipids in eukaryotes and it is increasingly recognized that the accumulation of LDs is a new hallmark of cancer cells. Furthermore, an active role of LD proteins in processes underlying tumorigenesis has been proposed. Here, by focusing on three major classes of LD-resident proteins (perilipins, lipases, and acyl-CoA synthetases), we provide an overview of the contribution of LDs to cancer progression and discuss the role of LD proteins during the proliferation, invasion, metastasis, apoptosis, and stemness of cancer cells.

Apocrine carcinoma with marked sebocyte-like cytological features: A report of two cases

Apocrine carcinoma cases with sebaceous differentiation have not been reported and can be misdiagnosed as sebaceous carcinoma. We present two cases of apocrine carcinoma with marked sebocyte-like cytological features. Tumors were observed in the left axilla of a 68-year-old man (Case 1) and the right axilla of a 72-year-old man (Case 2). Both patients presented with multiple lymph node metastases. Histopathology revealed densely distributed solid nests of tumor cells containing foamy cytoplasm and enlarged round nuclei with prominent nucleoli. The tumor cells diffusely expressed adipophilin, PRAME (cytoplasmic pattern), androgen receptor, BerEP4, and GCDFP15 but did not express p63 in both cases. PIK3CA E726K and H1047R mutations were detected in Cases 1 and 2, respectively. Tumor location in the axilla, the presence of eosinophilic granular cytoplasm, prominent nucleoli, and PIK3CA mutations, immunoreactivity for BerEP4 and GCDFP15, and lack of p63 immunoexpression findings matched apocrine carcinoma characteristics, but not sebaceous carcinoma. Thus, apocrine carcinoma can demonstrate intracytoplasmic lipid accumulation and rarely exhibit sebocyte-like cytological features. Apocrine carcinoma should be distinguished from sebaceous carcinoma due to the former's higher metastatic potential and lack of association with Muir-Torre syndrome.

Apocrine Cystadenoma of the Eyelid, a Rare Neoplasm: Expanded Immunohistologic Profile

An 83-year-old woman experienced the slow enlargement of a right lower eyelid mass. Histopathologic examination of the excised tissue showed a mucin-filled cystic tumor emanating from an apocrine bilayer that displayed bleb-like apocrine decapitation secretion. The outer flattened myoepithelial layer of the bilayer reacted with immunohistochemical stains for smooth muscle actin and calponin. In foci, the tumor exhibited a cribriform architecture with small pockets of mucin. Tumor cells were reactive for cytokeratin 7, Gross Cystic Disease Fluid Protein 15 (BRST-2), estrogen and progesterone receptors, androgen receptors, mammaglobin, epithelial membrane antigen, and GATA3. Ki67 showed a very low proliferation fraction. The lesion exemplifies the fourth instance of an eyelid apocrine cystadenoma in the literature.

Adipophilin: roles in physiology and pathology

Adipophilin (ADRP/ADPH/PLIN2), an adipocyte differentiation-related protein, is highly expressed at a very early time during the differentiation of adipocytes. It assists in the formation and maintenance of intracellular lipid droplets and plays a role in regulating the physiological functions of the body. More and more studies indicate that it is involved in the occurrence and development of a variety of glycolipid metabolic diseases and tumours. In this review, we comprehensively stated the expression and functions of adipophilin and introduced its roles in physiology and pathology.

AMACR Expression is a Potential Diagnostic Marker in Apocrine Lesions of Breast, and is Associated with High Histologic Grade and Lymph Node Metastases in Some Invasive Apocrine Breast Cancers

BACKGROUND

Carcinoma with apocrine differentiation (AC) is a subtype of breast carcinoma with apocrine features in >90% of the tumor. Molecular studies demonstrate AC has high expression of androgen receptor (AR) mRNA. Pure AC lack estrogen receptor (ER), progesterone receptor (PR), and express AR, with variable human epidermal growth factor 2 (HER2) status. Currently, in triple negative AC, no targetable therapies or specific diagnostic markers exist.

MATERIALS AND METHODS

α-Methylacyl CoA racemase (AMACR) expression was investigated as a marker of apocrine differentiation using a single-plex immunoperoxidase stain, and a novel AMACR/p63 dual stain in a subset of cases, across 1) benign apocrine lesions (apocrine metaplasia, adenosis) 2) apocrine DCIS (ADCIS), 3) AC/ invasive ductal carcinoma (IDC) with apocrine features, 4) non-apocrine triple negative breast cancer (TNBC) and 5) IDC, no special type. A sub-set of cases were evaluated by tissue microarray.

RESULTS

AMACR expression was increased in both AC and ADCIS, with minimal expression in benign breast tissue, TNBC and IDC, NST cases. In invasive cases, those with positive AMACR (>5% positivity) were significantly associated with higher histologic grade (P = .006), initial N stage (chi squared 0.044), and lack of ER or PR expression (both P < .001), with no correlation with overall survival. Analysis of TCGA breast cancer datasets revealed AMACR expression was significantly higher in molecularly defined apocrine carcinomas relative to basal and luminal subtypes. Moreover, high AMACR expression predicted worse relapse-free and distant-metastasis free survival, among both ER-/PR-/Her2- and ER-/PR-/Her2+ breast cancer cohorts (log-rank P = .081 and .00011, respectively).

CONCLUSION

AMACR represents a promising diagnostic and prognostic marker in apocrine breast lesions. Further study is needed to determine the biologic and clinical significance of this protein in AC.

Poorly differentiated cutaneous apocrine carcinomas: histopathological clues and immunohistochemical analysis for the diagnosis of this unusual neoplasm

Primary cutaneous apocrine carcinoma (PCAC) is a rare cutaneous malignancy that is derived from apocrine glands. Histologically, these tumours can appear well-differentiated where diagnosis should be relatively straightforward. However, occasionally these tumours can exhibit high-grade features, and in such instances the diagnosis can be challenging. A retrospective analysis of 12 cases of poorly differentiated PCAC, obtained from large academic institutions, was performed, and summarised below. Immunohistochemical studies were performed in all cases with antibodies against CK7, p63, CAM 5.2, GCDFP-15, GATA3, CEA, PR, ER, HER2, calponin, SMA, androgen receptor and EMA. All 12 cases were poorly differentiated; however, there were some histopathological clues to the diagnosis of apocrine carcinoma; namely, the presence of focal glandular formation, acrosyringial involvement and the presence of single 'pagetoid' cells within epidermis. All tumours were consistently positive for CK7, GATA3 and GCDFP-15 and negative for p63. The tumours had variable expression of CAM5.2, CEA, ER, PR, HER2, androgen receptor and EMA. In three cases, there was a preservation of the myoepithelial cell layer (with calponin and SMA), which also confirmed the primary cutaneous origin. PCAC is a difficult neoplasm to diagnose, as it can appear identical to metastatic carcinomas. We describe 12 cases of poorly differentiated PCAC, highlighting their salient clinical, histopathological and immunohistochemical features, and discuss the potential diagnostic pitfalls in distinguishing this entity from other malignant neoplasms. Our results indicate that a combination of thorough histological inspection coupled with an adequate battery of immunohistochemical stains is necessary to support the diagnosis of PCAC.

Reappraisal and literature review of primary cutaneous cribriform apocrine carcinoma

Primary cutaneous cribriform apocrine carcinoma (PCCAC) is an exceedingly rare sweat gland carcinoma. Clinically, it most often presents as a singular, asymptomatic nodule or cyst on the extremities of middle-aged patients and follows an indolent course. Both visceral and cutaneous cribriform tumors exist in nature. While a cribriform pattern is well recognized in tumors of visceral organs, there is a paucity in the literature on the defining characteristics for primary cutaneous tumors. Consensus regarding diagnostic criteria, etiology, and management protocols has yet to be achieved. We conducted an extensive literature review using pre-determined search criteria, resulting in 12 identified case reports and series on PCCAC that were subsequently analyzed. All data were compiled to provide a comprehensive update on the existing information regarding clinical presentation, histopathology, and management of reported PCCACs, as well as differential diagnosis, controversial issues, and recommendations for future considerations.

Ex vivo analysis of DNA repair targeting in extreme rare cutaneous apocrine sweat gland carcinoma

Cutaneous apocrine carcinoma is an extreme rare malignancy derived from a sweat gland. Histologically sweat gland cancers resemble metastatic mammary apocrine carcinomas, but the genetic landscape remains poorly understood. Here, we report a rare metastatic case with a PALB2 aberration identified previously as a familial susceptibility gene for breast cancer in the Finnish population. As PALB2 exhibits functions in the BRCA1/2-RAD51-dependent homologous DNA recombination repair pathway, we sought to use ex vivo functional screening to explore sensitivity of the tumor cells to therapeutic targeting of DNA repair. Drug screening suggested sensitivity of the PALB2 deficient cells to BET-bromodomain inhibition, and modest sensitivity to DNA-PKi, ATRi, WEE1i and PARPi. A phenotypic RNAi screen of 300 DNA repair genes was undertaken to assess DNA repair targeting in more detail. Core members of the HR and MMEJ pathways were identified to be essential for viability of the cells. RNAi inhibition of RAD52-dependent HR on the other hand potentiated the efficacy of a novel BETi ODM-207. Together these results describe the first ever CAC case with a BRCAness genetic background, evaluate combinatorial DNA repair targeting, and provide a data resource for further analyses of DNA repair targeting in PALB2 deficient cancers.

Current Diagnosis and Treatment Options for Cutaneous Adnexal Neoplasms with Apocrine and Eccrine Differentiation

Adnexal tumors of the skin are a rare group of benign and malignant neoplasms that exhibit morphological differentiation toward one or more of the adnexal epithelium types present in normal skin. Tumors deriving from apocrine or eccrine glands are highly heterogeneous and represent various histological entities. Macroscopic and dermatoscopic features of these tumors are unspecific; therefore, a specialized pathological examination is required to correctly diagnose patients. Limited treatment guidelines of adnexal tumor cases are available; thus, therapy is still challenging. Patients should be referred to high-volume skin cancer centers to receive an appropriate multidisciplinary treatment, affecting their outcome. The purpose of this review is to summarize currently available data on pathogenesis, diagnosis, and treatment approach for apocrine and eccrine tumors.

Androgen receptor expression in epidermal and adnexal tumours

INTRODUCTION

Androgen receptor (AR) immunohistochemistry is used in general pathology and in dermatopathology, particularly for sebaceous tumours. The goal of this study was to quantify AR expression in benign and malignant epidermal tumours and adnexal tumours.

METHODS

We studied AR expression in 301 skin lesions using standard immunohistochemistry and compared 10 trichoblastomas, 10 sebaceomas and 10 hidradenomas using 5 markers (cytokeratin 7 and 8, PHLDA1, BerEp4 and AR).

RESULTS

The rates of AR expression were: 22% in basal cell carcinomas, 3% in squamous cell carcinomas, 92% in sebaceous tumours, 10% in follicular tumours and 22% in sweat gland tumours. Benign sebaceous tumours were AR+ in 97% of cases. Only 12% of sebaceous carcinomas showed no AR staining. The immunohistochemical profiles of the comparative study were as follows: sebaceoma: AR+, CK7-, CK8-, PHLDA1-, BerEp4-; hidradenoma: AR-, CK7+, CK8+, PHLDA1+, BerEp4+; trichoblastoma: AR-, CK7-, CK8-, PHLDA1+, BerEp4+.

DISCUSSION

AR staining was positive in 92% of sebaceous tumours, including sebaceomas, in some cases indicative of Muir-Torre syndrome. AR staining is therefore highly sensitive for the diagnosis of sebaceous tumours, but it is non-specific and is best used in combination with other antibodies, notably anti-CK8 and PHLDA1, particularly to distinguish sebaceoma from hidradenoma or trichoblastoma.

Metastatic cutaneous apocrine adenocarcinoma successfully treated with systemic anti-androgen therapy-A case report

Primary cutaneous apocrine adenocarcinoma (PCAC) is an extremely rare neoplasm involving the sweat glands. Due to a lack of cases, there is no consensus for the systemic treatment of locally advanced or metastatic PCAC. Anti-androgen therapy may have activity in inoperable or metastatic PCAC with high androgen receptor (AR) expression.

Primary Extra Mammary Paget's Disease of Vulva, With Apocrine Adenocarcinoma, Signet Ring Cell Differentiation and Distant Metastasis

Objective: Extramammary Paget's disease (EMPD) with invasive carcinoma and distant metastasis is extremely rare. In vulva EMPD associated apocrine carcinoma with signet ring cell differentiation has not been described in the literature so far. Its slow evolution, varied clinical presentation and histological appearances, lead to difficulty in diagnosis of this disease. Case report: We hereby report a case of primary EMPD with invasive carcinoma and distant metastasis in a 59-year-old female who presented with erythematous indurated plaque over vulva. Histopathology revealed Paget cell infiltration throughout the epidermis with invasive carcinoma in dermis and liver metastasis on CECT. The immunohistochemical expressions of CK7, CK20, GCDFP-15, CEA, p40, CDX 2, Her-2/ neu, AR, ER, were examined to explicate the cellular differentiation of this carcinoma. According to the histological assessment, this case was diagnosed as primary EMPD with apocrine adenocarcinoma, signet ring cell differentiation, vulva. Conclusion: Owing to poor prognosis, a high index of clinical suspicion along with histological and immunohistochemical assessment is of utmost importance in arriving at final diagnosis.

Breast Atypical Apocrine Adenosis: A Case Report and Literature Review

Atypical apocrine adenosis (AAA) is a benign lesion of the breast that is identified more frequently today than in the past when it was considered a rare diagnosis and commonly misdiagnosed as other malignant lesions of the breast. AAA is defined as the presence of apocrine cytology in a recognisable lobular unit associated with sclerosing adenosis. We present a case of an incidental finding of AAA and discuss diagnostic challenges and their implications on clinical management.

Lipid droplets: platforms with multiple functions in cancer hallmarks

Lipid droplets (also known as lipid bodies) are lipid-rich, cytoplasmic organelles that play important roles in cell signaling, lipid metabolism, membrane trafficking, and the production of inflammatory mediators. Lipid droplet biogenesis is a regulated process, and accumulation of these organelles within leukocytes, epithelial cells, hepatocytes, and other nonadipocyte cells is a frequently observed phenotype in several physiologic or pathogenic situations and is thoroughly described during inflammatory conditions. Moreover, in recent years, several studies have described an increase in intracellular lipid accumulation in different neoplastic processes, although it is not clear whether lipid droplet accumulation is directly involved in the establishment of these different types of malignancies. This review discusses current evidence related to the biogenesis, composition and functions of lipid droplets related to the hallmarks of cancer: inflammation, cell metabolism, increased proliferation, escape from cell death, and hypoxia. Moreover, the potential of lipid droplets as markers of disease and targets for novel anti-inflammatory and antineoplastic therapies will be discussed.

A clinical, pathological and immunohistochemical series of 9 cases of primary cutaneous apocrine carcinomas of the head and neck

BACKGROUND/OBJECTIVES

Primary cutaneous apocrine carcinoma is a rare malignant adnexal skin tumour that can recur locally, spread to regional lymph nodes and metastatize to visceral organs. Wide dissemination and death from disease are much less common. The axilla is the most common site of presentation. It is infrequently reported in the head and neck region.

METHODS

All cases diagnosed as primary cutaneous apocrine carcinoma of the head and neck were retrospectively collected from the archives of the Division of Pathological Anatomy, University of Florence from 1996 to 2016. There was no history or clinical evidence of breast cancer. Clinical data and follow-up were collected by the clinicians.

RESULTS

Nine cases were found, with a mean age of 76 years, ranging in size between 0.3 and 3.5 cm. Clinically, they were frequently mistaken for basal cell carcinomas. Histopathologically, all the tumours showed decapitation secretion, a tubular, solid or mixed (tubulo-papillary and solid-tubular) growth pattern and were predominantly classified as grade 2 tumours. GCDFP-15 and hormone receptors were variably expressed. HER2 and podoplanin were negative in all cases. In one case, spreading to regional lymph nodes was observed. No cases were associated with death due to the disease.

CONCLUSION

As immunohistochemical analysis lacks specificity in distinguishing primary cutaneous apocrine carcinoma from a cutaneous metastasis of breast carcinoma, detailed clinical history, breast examination, adequate treatment and follow-up are necessary to confirm a diagnosis of primary cutaneous apocrine carcinoma.

Heterogeneity of PD-L1 expression and CD8 tumor-infiltrating lymphocytes among subtypes of cutaneous adnexal carcinomas

BACKGROUND

Adnexal carcinomas are rare and heterogeneous skin tumors, for which no standard treatments exist for locally advanced or metastatic tumors.

AIM OF THE STUDY

To evaluate the expression of PD-L1 and CD8 in adnexal carcinomas, and to study the association between PD-L1 expression, intra-tumoral T cell CD8+ infiltrate, and metastatic evolution.

MATERIALS AND METHODS

Eighty-three adnexal carcinomas were included. Immunohistochemistry using anti-PD-L1 monoclonal antibodies (E1L3N and 22C3) and CD8 was performed. PD-L1 expression in tumor and immune cells, and CD8+ tumor-infiltrating lymphocyte (TIL) density were analyzed semi-quantitatively.

RESULTS

Among the 60 sweat gland, 18 sebaceous and 5 trichoblastic carcinomas, 11% expressed PD-L1 in ≥ 1% tumor cells, more frequently sweat gland carcinomas (13%, 8/60) including apocrine carcinoma (40%, 2/5) and invasive extramammary Paget disease (57%, 4/7). Immune cells expressed significantly more PD-L1 than tumor cells (p < 0.01). Dense CD8+ TILs were present in 60% trichoblastic, 43% sweat gland, and 39% sebaceous carcinomas. CD8+ TILs were associated with PD-L1 expression by tumor cells (p < 0.01). Thirteen patients out of 47 developed metastases (27%) with a median follow-up of 30.5 months (range 7-36). Expression of PD-L1 by tumor cells was associated with the development of metastasis in univariate analysis (HR 4.0, 95% CI 1.1-15, p = 0.0377) but not in multivariate analysis (HR 4.1, 95% CI 0.6-29, p = 0.15).

CONCLUSION

PD-L1 expression is highly heterogeneous among adnexal carcinoma subtypes, higher in apocrine carcinoma and invasive extramammary Paget disease, and associated with CD8+ TILs. Our data suggest the interest of evaluating anti-PD1 immunotherapy in advanced or metastatic cutaneous adnexal carcinoma.

Transcriptome analyses reveal FOXA1 dysregulation in mammary and extramammary Paget's disease

Paget's disease (PD) is an uncommon intraepithelial adenocarcinoma with unknown pathogenesis. There are two anatomic subtypes: mammary (MPD) and extramammary (EMPD). Little is known about their molecular characteristics. Our objective was to discover novel molecular markers for PD and its subtypes. In the discovery phase, we used transcriptome analyses to uncover the most differentially expressed genes and pathways in EMPD biopsies compared with normal skin. In the validation phase, we performed immunohistochemistry analyses on the most promising marker (FOXA1) and other markers selected from a literature review (GATA3, estrogen receptor [ER], and androgen receptor [AR]) on independent biopsies of MPD (n = 86), EMPD (n = 59), and normal skin (n = 21). Transcriptome analyses revealed 210 genes differentially expressed more than 10-fold between EMPD and normal skin. These genes are involved in mammary and sweat gland development (FOXA1) and immune regulation, as well as epidermal differentiation. Immunohistochemistry staining revealed that FOXA1 was positive in 88% of both MPD and EMPD, whereas GATA3 was positive in 67% of MPD and 77% of EMPD, and ER was positive in 9% of MPD and 19% of EMPD. Finally, AR was positive in 33% of PD and 54% of EMPD. Mammary Paget's disease and EMPD share dysregulation of the glandular developmental regulator gene FOXA1, suggesting similarity in cell-specific transcriptional regulation. Further, FOXA1 may be a useful molecular target for developing PD therapies.

Salivary Duct Carcinoma and Invasive Ductal Carcinoma of the Breast: A Comparative Immunohistochemical Study

Salivary duct carcinoma (SDC) is a high-grade salivary gland malignancy with great morphological resemblance to invasive ductal carcinoma (IDC) of the breast. Rarely, female patients may have a past history of both SDC and IDC. When these patients present with distant metastasis, accurate identification of the primary tumor is particularly difficult. Additionally, rare metastasis of SDC to the breast and IDC to the salivary (parotid) gland can also present a diagnostic challenge. Our aim was to develop an immunohistochemical panel that reliably distinguishes SDC from IDC. We included all SDCs diagnosed from 1989 to 2016 (23 cases) and 29 treatment naïve and histologically similar IDCs. All cases were stained with androgen receptor (AR), estrogen receptor-alpha (ER-α), progesterone receptor (PR), HER-2, CK5/6, p63, and beta-catenin. The great majority (> 90%) of both SDCs and IDCs reacted positively to AR. The main discrepancy in the immunohistochemical profiles was a distinctly different reactivity to ER-α, PR and HER-2. While 28 IDCs (96.6%) reacted positively to ER-α and/or PR, the majority expressing both (82.8%) with a moderate to strong staining intensity, only 2 SDCs expressed ER-α (8.7%) and 5 others expressed PR (21.7%) with only one case expressing both (P value < 0.05). On the other hand, 8 SDC (34.8%) were positive for HER-2 while none of the IDCs were positive (P value < 0.05). ER-α, PR, and HER-2 may be helpful to distinguish SDC from IDC. Positive reactivity to ER-α, PR or both and negative HER-2 favors a diagnosis of IDC while ER-α, PR negative, HER-2 positive tumors are more likely SDC.

[Atypical course of an apocrine sweat gland carcinoma of the axilla : A very rare malignant tumor and its interdisciplinary treatment]

We report on an atypical clinical course of a patient with the very rare diagnosis of an apocrine sweat gland carcinoma with lymphatic metastasis, a single metachronous distant metastasis and a now reached survival time of more than 4 years and give a review about the current literature. Only a very small number of cases have been described. The recommendations for diagnostics and treatment of this tumor, therefore, are not based on prospective randomized studies but upon case reports and on new immunohistochemical and genetic markers.

GATA3 and MYB Expression in Cutaneous Adnexal Neoplasms

Knowledge of staining pattern of certain immunostains might be useful in the classification of cutaneous adnexal tumors that can have clinical importance. We studied GATA3 and MYB expression in archival materials of 220 adnexal tumors comprised of sebaceous carcinomas, follicular tumors, apocrine carcinoma, predominantly apocrine tumors, predominantly eccrine tumors, and others including adenoid cystic carcinomas. Nuclear GATA3 expression was seen in 70% (153/220) of cases, including sebaceous carcinoma (93%), apocrine carcinoma (93%), follicular neoplasms (100%), and predominantly apocrine neoplasms (69%), yet only 38% of predominantly eccrine neoplasms. Nuclear MYB expression was seen in 43% (81/188) of cases, including adenoid cystic carcinoma (90%), predominantly apocrine tumors (66%), follicular neoplasms (49%), apocrine carcinomas (14%), predominantly eccrine tumors (11%), and sebaceous carcinomas (4%). GATA3 and MYB expression were noted in 43% (9/21) and 24% (5/21) of cutaneous metastases, respectively. Expression of both GATA3 and MYB was noted in 33% (60/184) of primary adnexal tumors versus 19% (4/21) of cutaneous metastases. GATA3 preferentially labels tumors with follicular, sebaceous, and apocrine differentiation. MYB is potentially a helpful stain in the distinction of desmoplastic trichoepithelioma versus basal cell carcinoma. The coexpression of GATA3 and MYB might be helpful in the distinction of primary cutaneous adnexal carcinoma versus metastatic breast, salivary gland, or urothelial carcinoma.

"Secretory" Carcinoma of the Skin Mimicking Secretory Carcinoma of the Breast: Case Report and Literature Review

Secretory carcinoma is a unique kind of adenocarcinoma. It has distinct histological features and a special genetic change, that is, t (12; 15) (p13; q25) translocation which leads to the expression of the ETV6-NTRK3 fusion gene. Secretory carcinoma has been found to occur both in the breast and salivary gland. Here the authors present a case of 22-year-old woman with a unique cutaneous neoplasm located at the axilla. The tumor was characterized histologically with the formation of round to ovoid microcysts and papillary structure, which was similar to the secretory carcinoma of the breast and salivary gland. Furthermore, the gene sequence analysis of reverse-transcription polymerase chain reaction products demonstrated the expression of the ETV6-NTRK3 fusion gene. To the authors' knowledge, this is the first case of secretory carcinoma from the skin which has the same genetic change as those from the breast and salivary gland. Local excision was performed on this patient. She had been followed up for nearly 1 year. No recurrence or metastasis was found yet.

GATA3 Expression in Normal Skin and in Benign and Malignant Epidermal and Cutaneous Adnexal Neoplasms

Initial investigations reported GATA3 to be a sensitive and relatively specific marker for mammary and urothelial carcinomas. Recently, GATA3 expression has been described in several other epithelial tumors. However, there has been only limited investigation of GATA3 expression in cutaneous epithelial tumors. The objective of this study was to examine the immunohistochemical expression of GATA3 in a wide variety of cutaneous epithelial neoplasms. GATA3 expression was evaluated in 99 benign and 63 malignant cutaneous epithelial tumors. GATA3 was consistently and usually strongly expressed in clear cell acanthoma, trichofolliculoma, trichoepithelioma, trichilemmoma, sebaceous adenoma, sebaceoma, apocrine hidrocystoma, apocrine tubular papillary adenoma, hidradenoma papilliferum, and syringocystadenoma papilliferum. Hidradenomas exhibited variable positive staining. Most poromas, syringomas, chondroid syringomas, cylindromas, and spiradenomas were negative or only focally and weakly positive. Focal staining was present in all pilomatrixomas. Thirteen of 14 basal cell carcinomas, 21 of 24 squamous carcinomas, and all 6 sebaceous carcinomas exhibited positive staining. The 1 apocrine carcinoma, both mucinous carcinomas, and 2 of 3 microcystic adnexal carcinomas also exhibited positive staining, whereas the 1 eccrine porocarcinoma and the 1 adenoid cystic carcinoma were negative. One of 11 Merkel cell carcinomas exhibited focal weak staining. Our findings demonstrate that GATA3 is expressed in a wide variety of benign and malignant cutaneous epithelial neoplasms. In addition to carcinomas of breast and urothelial origin and other more recently described GATA3-positive tumors, the differential diagnosis of a metastatic tumor of unknown primary origin that expresses GATA3 should also include a carcinoma of cutaneous epithelial origin.

GATA-binding protein 3 enhances the utility of gross cystic disease fluid protein-15 and mammaglobin A in triple-negative breast cancer by immunohistochemistry

AIMS

We have demonstrated previously that gross cystic disease fluid protein-15 (GCDFP-15) and mammaglobin A (MAM) are of limited utility in triple-negative breast cancer (TNBC). GATA-binding protein 3 (GATA-3) is an emerging breast-associated immunohistochemical (IHC) marker with limited data in TNBC. Here, we examined GATA-3 expression in TNBC in comparison with GCDFP-15 and MAM.

METHODS AND RESULTS

We studied GATA-3, GCDFP-15 and MAM IHC expression in 62 primary and 68 metastatic TNBCs. In primary TNBCs, GATA-3 staining was observed in 25 cases (40%), including 16 cases that were negative for GCDFP-15 and MAM. In metastatic TNBCs, GATA-3 staining was observed in 30 cases (44%), including 16 cases that were negative for GCDFP-15 and MAM. The expression frequency of any of the markers was 56% in primary and 62% in metastatic TNBCs. However, when focal staining was excluded, the expression frequency of any marker dropped to 31% and 44%, respectively.

CONCLUSION

GATA-3 is expressed at a higher frequency by IHC in TNBC compared to GCDFP-15 and MAM, although the tissue specificity of the latter markers may be superior. When evaluating a triple-negative tumour, including GATA-3 in a panel of markers may increase the diagnostic accuracy for tissue origin in the appropriate clinical setting.

Recurrent apocrine carcinoma of the scrotum: a case report

Apocrine carcinoma is a rare tumor of the skin that typically arises in areas rich in apocrine glands, such as axilla and perineum. The main differential diagnosis is a metastasis from a primary apocrine carcinoma of the breast. Several authors have attempted to define morphological and immunohistochemical parameters to differentiate metastasis from primary apocrine carcinoma of the skin, but none of these had been demonstrated to be reliable markers. Here, we report a case of primary apocrine carcinoma of the scrotum that relapsed three times within a few years, without any clinical or radiological evidence of any other tumor of breast or other sites.