Use of Ber-EP4 and Epithelial Specific Antigen to Differentiate Clinical Simulators of Basal Cell Carcinoma

Utility of GLI1 RNA Chromogenic in Situ Hybridization in Distinguishing Basal Cell Carcinoma From Histopathologic Mimics

Basal cell carcinoma (BCC) is the most common human malignancy and is a leading cause of nonmelanoma skin cancer-related morbidity. BCC has several histologic mimics which may have treatment and prognostic implications. Furthermore, BCC may show alternative differentiation toward a variety of cutaneous structures. The vast majority of BCCs harbor mutations in the hedgehog signaling pathway, resulting in increased expression of the GLI family of transcription factors. GLI1 immunohistochemistry has been shown to discriminate between several tumor types but demonstrates high background signal and lack of specificity. In this study, we evaluated the utility of GLI1 RNA chromogenic in situ hybridization (CISH) as a novel method of distinguishing between BCC and other epithelial neoplasms. Expression of GLI1 by RNA CISH was retrospectively evaluated in a total of 220 cases, including 60 BCCs, 37 squamous cell carcinomas (SCCs) including conventional, basaloid, and human papillomavirus infection (HPV)-associated tumors, 16 sebaceous neoplasms, 10 Merkel cell carcinomas, 58 benign follicular tumors, and 39 ductal tumors. The threshold for positivity was determined to be greater than or equal to 3 GLI1 signals in at least 50% of tumor cells. Positive GLI1 expression was identified in 57/60 BCCs, including metastatic BCC, collision lesions with SCC, and BCCs with squamous, ductal, or clear cell differentiation or with other unusual features compared to 1/37 SCCs, 0/11 sebaceous carcinomas, 0/5 sebaceomas, 1/10 Merkel cell carcinomas, 0/39 ductal tumors, and 28/58 follicular tumors. With careful evaluation, GLI1 RNA CISH is highly sensitive (95%) and specific (98%) in distinguishing between BCC and nonfollicular epithelial neoplasms. However, GLI1 CISH is not specific for distinguishing BCC from most benign follicular tumors. Overall, detection of GLI1 RNA by CISH may be a useful tool for precise classification of histologically challenging basaloid tumors, particularly in the setting of small biopsy specimens, metaplastic differentiation, or metastatic disease.

Ber-EP4 staining patterns on basal cell carcinomas

OBJECTIVE

This article aimed to study two different parameters of basal cell carcinoma (BCC): First, to analyze the expression of antihuman epithelial antigen (Ber-EP4) on the primary and recurrent BCCs on the head, neck, and other body parts and second, to find Ber-EP4's staining pattern and staining intensities correlation between histological type, demographic data, tumor, and its prognostic parameters.

METHODS

We evaluated the Ber-EP4 staining patterns of 201 patients diagnosed with BCC. We analyzed the possible correlation between the tumor's prognostic parameters and the Ber-EP4 staining intensity and its pattern (peripheral, superficial, or diffused).

RESULTS

In 199 out of the 201 cases, staining was observed. Two cases were unstained. In 25.6% (n=51) of the cases with staining, the staining was weak, on the 25.6% (n=51), it was moderate, and on the 48.8% (n=97), it was severe. The staining pattern was 31.2% (n=62) peripheral, 4.0% (n=8) superficial, 54.7% (n=109) diffuse, and 10.1% (n=20) peripheral and superficial.

CONCLUSION

Ber-EP4 is the only antibody commonly used for BCC diagnosis; the existence of different staining intensities and patterns in BCC tumor cells in routine dermatopathology practice limit the pathologists. The studies investigating Ber-EP4 staining in BCCs were conducted with very small numbers of cases. In these studies, even the presence of staining in the focal area was considered to be a positive acceptance criterion; the staining intensity and pattern were not evaluated. Therefore, our study is the first study with a high number of cases and the first to include an evaluation of Ber-EP4 staining's intensity and localization.

Disease-related biomarkers as experimental endpoints in 3D skin culture models

The success of in vitro 3D models in either recapitulating the normal tissue physiology or altered physiology or disease condition depends upon the identification and/or quantification of relevant biomarkers that confirm the functionality of these models. Various skin disorders, such as psoriasis, photoaging, vitiligo, etc., and cancers like squamous cell carcinoma and melanoma, etc. have been replicated via organotypic models. The disease biomarkers expressed by such cell cultures are quantified and compared with the biomarkers expressed in cultures depicting the normal tissue physiology, to identify the most prominent variations in their expression. This may also indicate the stage or reversal of these conditions upon treatment with relevant therapeutics. This review article presents an overview of the important biomarkers that have been identified in in-vitro 3D models of skin diseases as endpoints for validating the functionality of these models.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10616-023-00574-2.

Expression of BerEP4 and CD10 IHC Markers in Basal Cell Carcinoma, Squamous Cell Carcinoma and Adnexal Tumours of Follicular Differentiation: A Comparative Study

Background

Basal cell carcinoma (BCC) is the most common cutaneous malignancy. In most cases, BCC can be diagnosed by its characteristic histopathological features. The differential diagnosis includes basaloid squamous cell carcinoma (SqCC) and adnexal tumours of follicular differentiation. Cluster of differentiation 10 (CD10) and name of an immunostain (BerEP4) are reported to be useful in differentiating between them.

Objectives

The primary objective was to compare the expression of BerEP4 and CD10 in BCC with that of SqCC and adnexal tumours of follicular differentiation, and the secondary objective was to evaluate the proportion of different histological subtypes of BCC.

Materials and Methods

Twenty-eight cases of BCCs, 34 cases of SqCCs and 16 adnexal tumours of follicular differentiation received in the institution during the study period January 2017 to June 2018 were included in this descriptive study. Immunostaining with CD10 and BerEP4 was performed, and the staining pattern was studied in all 78 cases. A detailed histopathological evaluation including subtyping was carried out for BCC cases.

Results

All BCCs showed positivity with CD10 and BerEP4, but the intensity and pattern varied. Squamous cell carcinomas were completely negative for BerEP4 and CD10 in tumour cells, and 25 of 34 cases showed stromal CD10 positivity. Among adnexal tumours of follicular differentiation, proliferating trichilemmal tumour was completely negative for both markers; other adnexal tumours (n = 11/16) showed peritumoral stromal accentuation for CD10, and nine of 11 cases showed BerEP4 tumour cell positivity (P < 0.001).

Conclusion

BerEP4 can reliably detect BCCs of all types and distinguish between BCC and SqCC, but it is unable to do so for adnexal tumours such as trichoepithelioma, trichilemmoma and trichoblastoma. CD10 is a useful adjunct marker in distinguishing both trichoepithelioma (TE) and SqCC from BCC. CD10-positive tumour cells favour a diagnosis of BCC and peritumoral stromal accentuation for trichoblastoma (TB) and trichilemmoma (TL). Tumour cells in SqCC are almost always negative for CD10. A combined immunohistochemistry (IHC) panel of CD10 and BerEP4 can serve as a very reliable adjunctive in the diagnosis of BCC.

Extremely Rare Pulmonary Metastases of Skin Basal Cell Carcinoma: Report of Two Cases with Clinicopathological Features

Basal cell carcinoma (BCC) is the most frequent human skin cancer, but metastasizing BCC (MBCC) is extremely rare, developing in approximately 0.0028% to 0.55% of BCC patients. Herein, we report two cases of pulmonary MBCC. The first one developed in a 72-year-old male who underwent surgical resection due to multiple recurrences and adjuvant radiotherapy. Immunohistochemistry showed that neoplastic cells expressed Ber-EP4, CK5/6, p63, EMA (focally), BCL-2, and CD10, but were negative for CK7, CK20, S100, estrogen and progesterone receptors, and TTF-1. The second case is a 64-year-old female treated with vismodegib. Clinicopathological features and differential diagnoses are described.

Comparison of Immunohistochemical Expression of Cytokeratin 19, c-KIT, BerEP4, GATA3, and NUTM1 Between Porocarcinoma and Squamous Cell Carcinoma

ABSTRACT

Distinguishing porocarcinoma from squamous cell carcinoma (SCC) is clinically significant; however, differential diagnosis can often be challenging. This study sought to confirm the diagnostic utility of cytokeratin 19, c-KIT, BerEP4, GATA3, and NUTM1 immunohistochemistry in distinguishing porocarcinoma from SCC. Immunohistochemical analysis of cytokeratin 19, c-KIT, BerEP4, GATA3, and NUTM1 in 14 porocarcinomas and 22 SCCs was performed; the extents and intensities of expression of these markers were recorded. The statistical associations of the immunoexpression between porocarcinoma and SCC were analyzed using the Pearson χ2 test. Cytokeratin 19 was positive in 13 (92.9%) of 14 porocarcinomas, and for all the positive cases, staining was strong and evident in >20% of the tumor cells. By contrast, 9 (40.9%) of 22 SCCs expressed cytokeratin 19 (P = 0.0018), of which 6 showed extremely focal (≤10% of the tumor cells) expression. Of the 14 porocarcinomas, 11 (78.6%) cases showed c-KIT positivity, whereas only 3 of 22 SCCs (13.6%) expressed c-KIT focally (P = 0.0001). In addition, BerEP4 immunostaining differed between porocarcinomas and SCCs (57.1% vs. 9.1%, respectively; P = 0.0017). However, no significant difference between the groups was reported in terms of GATA3 expression (57.1% vs. 72.7%, respectively; P = 0.3336). NUTM1 was expressed in 4/14 (28.6%) porocarcinomas but not in the SCCs. Immunohistochemistry for cytokeratin 19, c-KIT, and BerEP4 could be helpful in distinguishing porocarcinomas from SCCs. In addition, NUTM1 immunoexpression is highly specific, although not sensitive, to porocarcinomas. GATA3 immunohistochemistry has no meaningful implications in the differential diagnosis of porocarcinoma and SCC.

Differences in actin expression between primary and recurrent facial basal cell carcinomas as a prognostic factor of local recurrence

Introduction

Due to a relatively high recurrence rate of facial basal cell carcinoma (BCC), its morbidity is very significant.

Aim

To analyse the expression of α-SMA, E-cadherin, Ber-Ep4 and MOC-31 as predictors of local recurrence in a group of patients with primary and recurrent BCCs of the face in correlation with histological and clinical data.

Material and methods

The study cohort included 79 patients with facial BCC (52 with primary BCC and 27 with recurrent BCC) who were treated at the Department of Cranio-Maxillofacial Surgery of the Jagiellonian University, Krakow in 1997-2009.

Results

Significant risk factors for local recurrence included: recurrent tumour (p = 0.001), multifocal BCC (p = 0.01), incomplete tumour excision (p = 0.02) and the aggressive infiltrating histologic subtype of BCC (p = 0.05). In the group of primary BCCs, positive expression of stromal α-SMA (p = 0.03) correlated with a statistically significant higher recurrence rate and so did positive expression of α-SMA in tumour cells of recurrent BCC (p = 0.002). In the group of primary aggressive BCC subtypes, reduced expression of MOC-31 was also associated with a higher rate of relapse (p = 0.02).

Conclusions

Our findings provide information about α-SMA and MOC-31 expression in primary and recurrent BCCs. These data may contribute to the formulation of a more targeted treatment plan and follow-up strategy for patients with facial basal cell carcinoma.

Antibody-Based Targeted Interventions for the Diagnosis and Treatment of Skin Cancers

BACKGROUND

Cutaneous malignancies most commonly arise from skin epidermal cells. These cancers may rapidly progress from benign to a metastatic phase. Surgical resection represents the gold standard therapeutic treatment of non-metastatic skin cancer while chemo- and/or radiotherapy are often used against metastatic tumors. However, these therapeutic treatments are limited by the development of resistance and toxic side effects, resulting from the passive accumulation of cytotoxic drugs within healthy cells.

OBJECTIVE

This review aims to elucidate how the use of monoclonal Antibodies (mAbs) targeting specific Tumor Associated Antigens (TAAs) is paving the way to improved treatment. These mAbs are used as therapeutic or diagnostic carriers that can specifically deliver cytotoxic molecules, fluorophores or radiolabels to cancer cells that overexpress specific target antigens.

RESULTS

mAbs raised against TAAs are widely in use for e.g. differential diagnosis, prognosis and therapy of skin cancers. Antibody-Drug Conjugates (ADCs) particularly show remarkable potential. The safest ADCs reported to date use non-toxic photo-activatable Photosensitizers (PSs), allowing targeted Photodynamic Therapy (PDT) resulting in targeted delivery of PS into cancer cells and selective killing after light activation without harming the normal cell population. The use of near-infrared-emitting PSs enables both diagnostic and therapeutic applications upon light activation at the specific wavelengths.

CONCLUSION

Antibody-based approaches are presenting an array of opportunities to complement and improve current methods employed for skin cancer diagnosis and treatment.

Adhesion Molecules in Non-melanoma Skin Cancers: A Comprehensive Review

Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the most frequently diagnosed cancers, generating significant medical and financial problems. Cutaneous carcinogenesis is a very complex process characterized by genetic and molecular alterations, and mediated by various proteins and pathways. Cell adhesion molecules (CAMs) are transmembrane proteins responsible for cell-to-cell and cell-to-extracellular matrix adhesion, engaged in all steps of tumor progression. Based on their structures they are divided into five major groups: cadherins, integrins, selectins, immunoglobulins and CD44 family. Cadherins, integrins and CD44 are the most studied in the context of non-melanoma skin cancers. The differences in expression of adhesion molecules may be related to the invasiveness of these tumors, through the loss of tissue integrity, neovascularization and alterations in intercellular signaling processes. In this article, each group of CAMs is briefly described and the present knowledge on their role in the development of non-melanoma skin cancers is summarized.

Trichoblastic carcinosarcoma in a 34-year-old woman with histopathologic and molecular analysis, including re-demonstration of a CDKN2A p.(R58*) mutation

Trichoblastic carcinosarcomas are rare, adnexal-type cutaneous carcinosarcomas that are thought to be related histogenetically to trichoblastomas, yet in which both the epithelial and stromal components show features of malignancy. Ten cases have been described in the literature thus far, with a predilection for the head and neck of older males. We present a case of cutaneous carcinosarcoma in sun-damaged skin of a 34-year-old woman showing features of a trichoblastic carcinosarcoma, with histopathologic analysis along with targeted next-generation sequencing of 50 cancer-associated genes. Two pathogenic variants in TP53 were identified, p.(R158C), p.(R273P), along with a likely pathogenic variant CDKN2A, p.(R58*). In particular, it is noted that the CDKN2A p.(R58*) missense mutation has been described in two previous cases of cutaneous carcinosarcomas, including a case of trichoblastic carcinosarcoma.

Utility of Ber-EP4 and MOC-31 in Basaloid Skin Tumor Detection

Ber-EP4 has been the traditional immunostain used for the detection of basaloid skin tumors. Recently, MOC-31 has shown be superior to Ber-EP4 in the detection of basosquamous basal cell carcinoma (BCC) and many centers are now using both Ber-EP4 and MOC-31 antibodies together to detect these lesions. The objective of this study was to compare the utility of using both Ber-EP4 and MOC-31 immunostains in the detection of basaloid skin tumors and to better characterize the previously unknown staining properties of MOC-31 in cutaneous lesions. To do this, 76 basaloid skin tumors stained with both Ber-EP4 and MOC-31 were obtained. Diagnoses included basosquamous BCC, Merkel cell carcinoma, adenoid cystic carcinoma, microcystic adnexal carcinoma, sebaceous carcinoma, trichoepithelioma, trichoblastoma, sebaceous adenoma, sebaceoma, and follicular induction overlying dermatofibroma. The distribution and intensity of Ber-EP4 and MOC-31 staining in these lesions was scored. These scores were analyzed using a truth table, χ test, and Pearson correlation tests. The overall mean and SD of the scores were also obtained. Overall, we found Ber-EP4 and MOC-31 to be statistically equivalent immunostains for the diagnosis of basaloid skin tumors. We recommend the use of only one of these antibodies and favor MOC-31 for the detection of basaloid skin tumors. We also describe MOC-31 staining properties in different cutaneous lesions.

Endoscopic features and associated histology of an basaloid squamous cell carcinoma of the esophagus at the very early stage

Background

Basaloid squamous cell carcinoma of the esophagus (BSCCE) is generally detected at advanced stage and the prognosis is poorer than advanced conventional esophageal squamous cell carcinoma. Therefore, early detection is a critical to improve patients’ survival. However, only a few cases of early BSCCE have been reported and the endoscopic features of early BSCCE are not well described. We herein report the endoscopic features and associated histology of an early BSCCE limited within the mucosal lamina propria (m2). To our knowledge, this is the earliest BSCCE reported to date.

Case presentation

A 62-year-old male patient was admitted to our hospital because of epigastric pain for 3 months. White light endoscopy revealed a flat lesion with mild sloping at the periphery. The lesion was covered with leukoplakia, and normal vascular network could not be seen in the lesion. Magnifying endoscopy with narrow-band imaging showed abnormal intra-papillary capillary loop categorized as type B1 according to the classification of the Japan Esophageal Society. Iodine staining revealed a less-stained lesion. The lesion was completely resected through endoscopic submucosal dissection. Histopathologically, tumor cells, which were limited within the mucosal lamina propria, formed solid nests and lobule structures, with ribbon-like arrangement of sparse cytoplasm and round to ovoid hyperchromatic nuclei. A final diagnosis of early BSCCE was established.

Conclusions

This is the earliest BSCCE reported to date. The prominent lesion with a gentle rising slope and less-staining or abnormal stain might be initial feature of early BSCCE.

Applications of SNAP-tag technology in skin cancer therapy

BACKGROUND

Cancer treatment in the 21st century has seen immense advances in optical imaging and immunotherapy. Significant progress has been made in the bioengineering and production of immunoconjugates to achieve the goal of specifically targeting tumors.

DISCUSSION

In the 21st century, antibody drug conjugates (ADCs) have been the focus of immunotherapeutic strategies in cancer. ADCs combine the unique targeting of monoclonal antibodies (mAbs) with the cancer killing ability of cytotoxic drugs. However, due to random conjugation methods of drug to antibody, ADCs are associated with poor antigen specificity and low cytotoxicity, resulting in a drug to antibody ratio (DAR) >1. This means that the cytotoxic drugs in ADCs are conjugated randomly to antibodies, by cysteine or lysine residues. This generates heterogeneous ADC populations with 0 to 8 drugs per an antibody, each with distinct pharmacokinetic, efficacy, and toxicity properties. Additionally, heterogeneity is created not only by different antibody to ligand ratios but also by different sites of conjugation. Hence, much effort has been made to find and establish antibody conjugation strategies that enable us to better control stoichiometry and site-specificity. This includes utilizing protein self-labeling tags as fusion partners to the original protein. Site-specific conjugation is a significant characteristic of these engineered proteins. SNAP-tag is one such engineered self-labeling protein tag shown to have promising potential in cancer treatment. The SNAP-tag is fused to an antibody of choice and covalently reacts specifically in a 1:1 ratio with benzylguanine (BG) substrates, eg, fluorophores or photosensitizers, to target skin cancer. This makes SNAP-tag a versatile technique in optical imaging and photoimmunotherapy of skin cancer.

CONCLUSION

SNAP-tag technology has the potential to contribute greatly to a broad range of molecular oncological applications because it combines efficacious tumor targeting, minimized local and systemic toxicity, and noninvasive assessment of diagnostic/prognostic molecular biomarkers of cancer.

Basal Cell Carcinoma Arises from Interfollicular Layer of Epidermis

Background

BCC is currently the most common type of skin cancer in humans. Although having a low-grade malignancy and metastatic potential, BCC is locally aggressive and destructive. Despite numerous studies, the origin of BCC, whether arising from the follicular or interfollicular layer, remains controversial.

Objectives

This study aims to evaluate whether BCC arises from the follicular or interfollicular layer by using immunohistochemical staining.

Methods

Twenty-three specimens of superficial and nodular BCC at its very early stage were examined. The samples were immunohistochemically stained using BerEP4 antibody. The stained specimens were then examined and scored by 2 independent observers.

Results

BerEP4 was found to be strongly positive in all BCC lesions, including a very early lesions budding off the basal layer of the epidermis.

Conclusion

This study confirmed that the origin site of BCC is basal layer of epidermis. This finding suggests that BCC arises from the interfollicular epidermis.

Cutaneous Basal Cell Carcinoma with Lymph Node and Pulmonary Metastases

Basal cell carcinoma (BCC) is the most common skin cancer. Metastatic BCC is an extraordinary rare finding observed in only 0.5% of all cases. Until the introduction of the small molecule hedgehog inhibitor vismodegib, patients with metastatic BCC were treated with chemotherapy, most frequently platinum-based with mixed responses to therapy. We present the case of a 55-year-old Caucasian man who suffered from BCC on his left arm with lymph node and pulmonary metastases. Sonic hedgehog blockade with vismodegib only induced a short remission, and the patient succumbed to the cancer.

The Use of BEREP4 Immunohistochemistry Staining for Detection of Basal Cell Carcinoma

Basal Cell Carcinoma (BCC) is the most common type of malignant cancer found in the world today with a 3–10% increase in incidence each year. The American Cancer Society reported that 8 out of 10 patients with skin cancer are suffering from BCC with over 2 million new cases each year. BCC needs to be detected at the early stages to prevent local destruction causing disabilities to patients and increasing treatment costs. Furthermore, BCC patients who have undergone surgery are still at risk for recurrence, especially when the surgery performed fails to remove all the BCC cells, even when conventional histopathological testing after surgery has reported a surgically free margin. This review aims to evaluate studies on the use of BerEP4 immunohistochemistry staining on pathological sections of various types of BCC as well as its shortfalls. BerEP4 is a monoclonal antibody which detects specific epithelial-glycoprotein-adhesion-molecules (EpCAM) found on BCC cells. Various studies have shown that BerEP4 has a high sensitivity and specificity in detecting only BCC cells. The use of BerEP4 immunohistochemistry testing for the routine examination of cases of BCC is expected to be able to increase and improve early diagnosis as well as prevent recurrence after surgery.

Histologic Mimics of Basal Cell Carcinoma

CONTEXT

- Basal cell carcinoma (BCC) is the most common human malignant neoplasm and is a frequently encountered diagnosis in dermatopathology. Although BCC may be locally destructive, it rarely metastasizes. Many diagnostic entities display morphologic and immunophenotypic overlap with BCC, including nonneoplastic processes, such as follicular induction over dermatofibroma; benign follicular tumors, such as trichoblastoma, trichoepithelioma, or basaloid follicular hamartoma; and malignant tumors, such as sebaceous carcinoma or Merkel cell carcinoma. Thus, misdiagnosis has significant potential to result in overtreatment or undertreatment.

OBJECTIVE

- To review key features distinguishing BCC from histologic mimics, including current evidence regarding immunohistochemical markers useful for that distinction.

DATA SOURCES

- Review of pertinent literature on BCC immunohistochemistry and differential diagnosis.

CONCLUSIONS

- In most cases, BCC can be reliably diagnosed by histopathologic features. Immunohistochemistry may provide useful ancillary data in certain cases. Awareness of potential mimics is critical to avoid misdiagnosis and resulting inappropriate management.

Automated selection of aptamers against cholangiocarcinoma cells on an integrated microfluidic platform

An integrated microfluidic system capable of automatically identifying aptamers specific to cholangiocarcinoma (CCA) cells was developed herein. The developed system was capable of performing cell-based systematic evolution of ligands via an exponential enrichment (Cell-SELEX) process on-chip, and only six rounds of Cell-SELEX were required to identify high specificity aptamers; this represents a significant improvement in speed over conventional SELEX, in which 15-20 rounds are typically required. Using the microfluidic chip developed, three aptamers specific to CCA cells (one for SNU-478 cells and two for HuCCT-1 cells) were successfully screened. This automated system could be modified to uncover aptamer probes against other cancer cells, thereby allowing for earlier diagnosis and consequently a potentially improved prognosis.

Implementation of fluorescence confocal mosaicking microscopy by "early adopter" Mohs surgeons and dermatologists: recent progress

Confocal mosaicking microscopy (CMM) enables rapid imaging of large areas of fresh tissue ex vivo without the processing that is necessary for conventional histology. When performed in fluorescence mode using acridine orange (nuclear specific dye), it enhances nuclei-to-dermis contrast that enables detection of all types of basal cell carcinomas (BCCs), including micronodular and thin strands of infiltrative types. So far, this technique has been mostly validated in research settings for the detection of residual BCC tumor margins with high sensitivity of 89% to 96% and specificity of 99% to 89%. Recently, CMM has advanced to implementation and testing in clinical settings by “early adopter” Mohs surgeons, as an adjunct to frozen section during Mohs surgery. We summarize the development of CMM guided imaging of ex vivo skin tissues from bench to bedside. We also present its current state of application in routine clinical workflow not only for the assessment of residual BCC margins in the Mohs surgical setting but also for some melanocytic lesions and other skin conditions in clinical dermatology settings. Last, we also discuss the potential limitations of this technology as well as future developments. As this technology advances further, it may serve as an adjunct to standard histology and enable rapid surgical pathology of skin cancers at the bedside.

Immunohistochemistry in dermatopathology

CONTEXT

Immunohistochemistry is not a diagnostic test but a highly valuable tool that requires interpretation within a context.

OBJECTIVE

To review the current status and limitations of immunohistochemistry in dermatopathology.

DATA SOURCES

English-language literature published between 1980 and 2014.

CONCLUSIONS

Although immunohistochemistry is rarely completely specific or sensitive, it is an important adjunctive technique in dermatopathology and can be helpful in a series of diagnostic dilemmas.

The importance of cytokeratin 19 expression in the differentiation of Basal cell carcinoma and trichoepithelioma

INTRODUCTION

Basal cell carcinoma (BCC) is the most common skin neoplasm reported in human. On the other hand, trichoepithelioma (TE) is a rare, benign tumour of skin adnexa. The differentiation of BCC and TE may be difficult since their morphological findings are similar. In a few studies, it has been determined that undifferentiated basaloid cells are highly positively stained with cytokeratin 19.

AIM

The aim of this study was the comparison of cytokeratin 19 expression in cases of BCC and TE.

MATERIALS AND METHODS

Sections of skin tissues of 17 TE, 25 BCC and 12 non-neoplastic cases were used for cytokeratin 19 (CK19) immunohistochemical staining.

RESULTS

Staining with CK19 of the BCC cases gave 15(60%) diffuse, 7 (28%) focal and 3 (12%) negative staining. On the other hand, among TE cases, 2 (12%) gave diffuse, 5 (29%) focal and 10 (59%) negative staining with CK19. In the non-neoplastic skin tissue samples, while positive staining with cytokeratin 19 in the outer root sheath of hair follicles and sweat glands were observed, there was no staining in basal layers.

CONCLUSION

CK19 expression may be helpful in the differential diagnosis of BCC and TE especially in small skin biopsy samples in which morphologic differentiation is difficult.

Corneal limbal sebaceous adenoma

PURPOSE

The aim of this study was to describe a case of a corneal limbal sebaceous adenoma.

METHODS

An 83-year-old male patient presented with a white solid nodular lesion covering most of the cornea of his right eye. The corneal lesion was removed totally. The corneal surface was reconstructed by amniotic membrane transplantation.

RESULTS

The histopathological examination of the lesion revealed the presence of a sebaceous adenoma. A systemic examination revealed no other abnormalities.

CONCLUSIONS

Sebaceous adenomas on the ocular surface are known to be very rare. To the best of our knowledge, this is the first case of a sebaceous adenoma located on the cornea, reported in the literature. It is of vital importance to make a differential diagnosis of sebaceous adenomas of the eyelid and conjunctiva with the Muir-Torre syndrome associated with visceral malignancies.

Multiscale BerEp4 molecular imaging of microtumor phantoms: toward theranostics for basal cell carcinoma

Basal cell carcinoma (BCC), the most common cancer in humans, appears macroscopically and microscopically similar to many other skin lesions, which makes differential diagnosis difficult. We are developing an approach for quantitative molecular imaging of BerEP4, a transmembrane biomarker for BCC, with the goal of increasing the precision and accuracy of diagnosis. This pilot study was conducted to assess the affinity and selectivity of BerEp4 antibody and assess its possible use in designing theranostic probes for BCC. We provide evidence that our photon-counting fluorescence macrodetection system can recover specific signal increases from a film/pellet phantom. Additionally, we show that a two-photon excited fluorescence /backscatter confocal microscopy system can image BerEP4 antibody/antigen complex on the surface of BerEP4-expressing cancer cells in three dimensions. Based on the initial results, BerEP4 seems to be a promising biomarker for molecular imaging of BCC. To prepare BerEP4 for eventual theranostic use, we examined the feasibility of a combined macro-/micro-optical approach to imaging BCC with various histologies. These optical methods, endowed with the ability to monitor treatment in real time, may open an opportunity for noninvasive diagnosis, treatments, and follow-up.