Novel quantitative immunohistochemistry method using histone H3, family 3B as the internal reference standard for measuring human epidermal growth factor receptor 2 expression in breast cancer

BACKGROUND

Immunohistochemistry (IHC) is an essential technique in surgical and clinical pathology for detecting diagnostic, prognostic, and predictive biomarkers for personalized cancer therapy. However, the lack of standardization and reference controls results in poor reproducibility, and a reliable tool for IHC quantification is urgently required. The objective of this study was to describe a novel approach in which H3F3B (histone H3, family 3B) can be used as an internal reference standard to quantify protein expression levels using IHC.

METHODS

The authors enrolled 89 patients who had human epidermal growth factor receptor 2 (HER2)-positive breast cancer (BC). They used a novel IHC-based assay to measure protein expression using H3F3B as the internal reference standard. H3F3B was uniformly expressed at the protein level in all tumor regions in cancer tissues. HER2 expression levels were measured with the H-score using HALO software.

RESULTS

Kaplan-Meier analysis indicated that, among patients who had HER2-positive BC in The Cancer Genome Atlas data set and the authors' data set, the subgroup with low HER2 expression had a significantly better prognosis than the subgroup with high HER2 expression. Furthermore, the authors observed that HER2 expression levels were precisely evaluated using the proposed method, which can classify patients who are at higher risk of HER2-positive BC to receive trastuzumab-based adjuvant therapy. Dual-color IHC with H3F3B is an excellent tool for internal and external quality control of HER2 expression assays.

CONCLUSIONS

The proposed IHC-based quantification method accurately assesses HER2 expression levels and provides insights for predicting clinical prognosis in patients with HER2-positive BC who receive trastuzumab-based adjuvant therapy.

Primary Epithelioid Sarcoma of the Conchal Bowl in a 64-Year-Old Male: A Case Report and Review of the Literature

ABSTRACT

Epithelioid sarcoma (ES) is a distinctive malignant mesenchymal neoplasm with atypical epithelioid cells palisading around a central zone of necrosis. ES is a rare entity even in soft tissue pathology. Immunohistochemically, tumors usually show diffuse epithelial membrane antigen and cytokeratin expression and loss of nuclear INI1 (SMARCB1) expression. Here, we report a case of a 64-year-old man with ES arising in the left conchal bowl. Given the clinical presentation including patient's age, sun-exposed area of skin, and slow-growing, asymptomatic, small pink pearly papule, this patient was initially misdiagnosed with basal cell carcinoma clinically and treated with topical imiquimod at an outside facility. The lesion continued to grow and eventually became symptomatic despite the treatment after which biopsy was obtained. Despite the unusual anatomic site and the patient's age, the microscopic and immunohistochemical findings were characteristic of conventional-type ES. Our case shows that ES can arise in rare locations and in older adults where it may be more easily misdiagnosed clinically and pathologically as a nonmelanoma skin cancer.

Diagnostic performance of melanocytic markers for immunocytochemical evaluation of lymph-node melanoma metastases on cytological samples

AIMS

The diagnosis of metastatic cutaneous melanoma (CM) on lymph node fine needle aspiration samples may be challenging and usually requires confirmation by immunocytochemistry. However, the cytological material could be too scant to order a broad panel of markers. In this case, the pathologist is forced to choose the most advantageous antibodies. The most commonly used melanocytic markers include S100, Melan-A, HMB45 and SOX10 but their diagnostic yield on cytological samples has been poorly studied. The current work aimed to evaluate the diagnostic performance of melanocytic markers when applied to cell blocks obtained from fine needle aspiration cytology (FNAC) of lymph node metastases from CM.

METHODS

S100, Melan-A, HMB45 and SOX10 were tested on cell block sections of 38 lymphnode metastases from CM diagnosed by cytology. A combined score was built to evaluate each immunostaining, considering the intensity of the staining and the percentage of stained neoplastic cells.

RESULTS

S100 and SOX10 revealed a higher sensitivity (100%) than Melan-A and HMB45 for the diagnosis of metastatic CM. Furthermore, SOX10 emerged as the melanocytic marker with the best staining performance.

CONCLUSION

SOX10 has a 100% detection rate and the most easily interpretable staining pattern compared with other melanocytic markers. Therefore, it is strongly recommended that SOX10 is included in the minimal immunocytochemical panel for the diagnostic evaluation of lymph node FNAC in patients with suspected CM metastasis.

Cytologic diagnosis of metastatic melanoma by FNA: A practical review

Malignant melanoma (MM) is a highly aggressive neoplasm with a growing worldwide incidence. It is not uncommon that the disease is already metastatic at the time of the first diagnosis. Regional lymph nodes and skin are the first and most common metastatic sites, followed by distant visceral sites (lungs, liver, and central nervous system) and bone. In this clinical setting, fine-needle aspiration (FNA) often represents the first diagnostic approach. FNA is a useful tool to obtain a rapid and accurate diagnosis, in conjunction with ancillary techniques and molecular analysis, as recommended by recent guidelines. The aim of this review was to describe the cytomorphology, immunocytochemical tools, and molecular tools used for the diagnosis of MM metastases on FNA.

Sex-Determining Region Y Chromosome-Related High-Mobility-Group Box 10 in Cancer: A Potential Therapeutic Target

Sex-determining region Y-related high mobility group-box 10 (SOX10), a member of the SOX family, has recently been highlighted as an essential transcriptional factor involved in developmental biology. Recently, the functionality of SOX 10 has been increasingly revealed by researchers worldwide. It has been reported that SOX10 significantly regulates the proliferation, migration, and apoptosis of tumors and is closely associated with the progression of cancer. In this review, we first introduce the basic background of the SOX family and SOX10 and then discuss the pathophysiological roles of SOX10 in cancer. Besides, we enumerate the application of SOX10 in the pathological diagnosis and therapeutic potential of cancer. Eventually, we summarize the potential directions and perspectives of SOX10 in neoplastic theranostics. The information compiled herein may assist in additional studies and increase the potential of SOX10 as a therapeutic target for cancer.

HOXA9 mediates and marks premalignant compartment size expansion in colonic adenomas

The transformation of normal colonic epithelium to colorectal cancer (CRC) involves a relatively ordered progression, and understanding the molecular alterations involved may aid rational design of strategies aimed at preventing or counteracting disease. Homeobox A9 (HOXA9) is an oncogene in leukemia and has been implicated in CRC pathology, although its role in disease etiology remains obscure at best. We observe that HOXA9 expression is increased in colonic adenomas compared with location-matched healthy colon epithelium. Its forced expression results in dramatic genetic and signaling changes, with increased expression of growth factors IGF1 and FLT3, super-activity of the AKT survival pathway and a concomitant increase in compartment size. Furthermore, a reduced mRNA expression of the epithelial to mesenchymal transition marker N-cadherin as well as reduced activity of the actin cytoskeletal mediator PAK was seen, which is in apparent agreement with an observed reduced migratory response in HOXA9-overexpressing cells. Thus, HOXA9 appears closely linked with adenoma growth while impairing migration and metastasis and hence is both a marker and driver of premalignant polyp growth. Colonic polyps grow but remain premalignant for up to decades. Here, we show that HOXA9 drives growth in premalignant polyps, but simultaneously prevents further transformation.

Epithelioid Hemangioendothelioma of the Bowel in Crohn's Disease: The First Reported Case

BACKGROUND

Epithelioid hemangioendothelioma (EHE) is an uncommon malignant endothelial neoplasm that most commonly arises in soft tissue, bone, lung, and liver. Crohn's disease (CD) is an inflammatory bowel disease of unknown etiology that is frequently associated with complications including strictures, fistulas/fissures, and neoplasms.

CASE DESCRIPTION

A 43-year-old woman with a 6-year history of severe CD presented with anal pain and bleeding. She had prior partial colectomy for a stricture and a diverting ileostomy for perianal fissures and stricture. Colonoscopy showed severe chronic active colitis, stricture at 30 cm of anal verge, and a perianal fistula. The patient underwent total proctocolectomy. The colonic mucosa exhibited segmental ulceration and irregular thickening of the colon wall. Beneath an ulcer of the anal canal within the muscularis propria was a 1.2-cm poorly circumscribed, firm, white-tan mass. The mass was composed of cords and groups of large epithelioid endothelial cells with intracytoplasmic vacuoles enmeshed in a myxohyaline stroma. Immunohistochemically, the tumor cells were positive for ERG, CD31, and CAMTA1 and focally positive for keratin and SMA. Next-generation sequencing revealed a WWTR1-CMATA1 fusion. The morphology, immunoprofile, and molecular genetics were diagnostic of EHE.

DISCUSSION

Long-standing inflammatory bowel disease is associated with significant risk for developing neoplasms, usually carcinomas, which can be indistinguishable radiologically and clinically from nonneoplastic complications. These tumors are often identified as an incidental finding in specimens resected for clinically severe disease. This is the first report of EHE arising in the bowel affected by CD, and it mimicked mural fibrosis and fissures.