Primary mediastinal (thymic) large B-cell lymphoma (PMBL) is described as almost always negative for Epstein-Barr virus (EBV). In the context of a mediastinal lymphoma, the distinction between PMBL, classical Hodgkin lymphoma, diffuse large B-cell lymphoma, and mediastinal gray-zone lymphoma can be very difficult; hence, EBV positivity often argues against PMBL. We present a 19-year-old man with mediastinal

In the era of precision medicine, accurate and reproducible assignment of cell-of-origin (COO) in diffuse large B-cell lymphoma patients has become important. The Lymph2Cx assay is accurately determining COO by analyzing RNA expression of 20 selected genes while the Hans algorithm based on immunohistochemistry is the most popular method for routine daily diagnosis. However, there are discrepancies

Background and Study Aims:  We aim to determine the frequency of thymidylate synthase (TS) and excision repair cross-complementation group 1 (ERCC-1) immunohistochemical (IHC) expression and its relationship with clinicopathologic variables in colorectal carcinoma (CRC) patients. In addition, we aim to assess the correlation between TS and ERCC-1 expression and the response of these cases to oxaliplatin

Gastric cancer (GC) is the fifth most common cancer and the third leading cause of cancer-related mortality worldwide. Although multidisciplinary therapeutic strategies have improved treatment outcomes, the overall prognosis for patients with GC remains poor. Recently, immunotherapeutic agents targeting immunosuppressive proteins such as anti-programmed death-1 receptor and anti-programmed death ligand-1

Background:  Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide. About 30% of patients present with metastatic disease involving predominantly the liver and a similar percentage will develop distant metastases later after removal of the primary tumor. In metastatic CRC, chemotherapies and biological drugs have prolonged survival for up to 30 months. However, there

Pheochromocytoma is a relatively uncommon tumor, and the histomorphologic and biochemical features that may portend malignant behavior have poor overall consensus across various proposed classification systems. Steroid receptor coactivator-1 (SRC-1) is a nuclear protein that mediates transcriptional activity. Current diagnostic applications of SRC-1 are limited, and include distinguishing adrenocortical

B7-H3 and B7-H4 play an inhibitory role in T-cell function by limiting proliferation and cytokine production. Information about B7-H3 and B7-H4 expression in ductal carcinoma in situ (DCIS) remains uncertain. The objective of this study was to evaluate the expression levels of B7-H3 and B7-H4 in DCIS and their associations with clinicopathologic features and T-cell infiltration. B7-H3 and B7-H4 mRNA

Solid pseudopapillary neoplasms (SPNs) and pancreatic neuroendocrine tumors (PanNETs) are distinctive entities. However, due to overlapping morphologies, distinguishing them remains a diagnostic challenge. Our study investigates the utility of immunohistochemistry for nuclear lymphoid enhancer binding factor 1 (LEF1) and paired box gene 8 (PAX8) in differentiating these 2 entities. LEF1 and PAX8 immunohistochemistry

Purpose:  Cat scratch disease (CSD) is an infectious disorder caused primarily by the bacterium Bartonella henselae (B. henselae). Immunohistochemistry (IHC) and Warthin-Starry silver stain (WS) are considered to be indispensable to diagnose CSD in combination with morphologic characteristics. In this study, we retrieved and reviewed 46 cases of paraffin-embedded lymphadenitis with histologic and/or

Intestinal metaplasia (IM) is a rare finding in urinary bladder specimens. It is unclear whether IM without dysplasia is a precursor of malignancy in the urinary system. We retrospectively selected 9 cases of IM of bladder (1 case harboring high-grade dysplasia), and performed mutation analysis for genes frequently mutated in colon cancer including BRAF, APC, KRAS, MET, NRAS, PIK3CA, CTNNB1, FBXW7

The importance of technical quality for histopathologic examination has only increased in recent years with the expanding use of digital pathology. The University of Kentucky Alzheimer’s Disease Center (UK-ADC) Neuropathology Core has decades of experience with brain histopathology and has emphasized the importance of quantitative assessments of histopathologic hallmarks. Technical artifacts and nonuniform

The renal injury caused by antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are characterized by few or no immune deposits in glomerulus. A growing number of AAV patients with glomerular immunoglobulin (Ig)A deposits have been reported. We retrospectively investigated all AAV patients with glomerular IgA deposits diagnosed in our center. Serum galactose-deficient IgA1 (Gd-IgA1)

We report 2 cases of composite lymphoma comprising mantle cell lymphoma and peripheral T-cell lymphoma, not otherwise specified, a rare association that has only been reported twice in the literature. In case 1, a 64-year-old woman presented with massive splenomegaly and lymphadenopathy. Immunohistochemical studies of the lymph node biopsy suggested the presence of 2 lymphomas, a predominant component

Glycogen-rich clear cell carcinoma (GRCC) is a very rare form of primary breast cancer (<0.1% of all breast cancers). It is characterized by the presence of neoplastic cells with a glycogen-abundant clear cytoplasm (the Periodic Acid Schiff–positive, diastase-sensitive). The expression of steroid receptors (estrogen and progesterone receptors) has been variably reported (35% to 100% of the cases),

The epithelial cell adhesion molecule (EpCAM) is involved in oncogenesis of hepatoblastomas (HBs). Prior genomic profiling studies showed higher EpCAM expression and worse prognosis in HBs containing primitive histotypes, however, this has not been fully addressed from an immunohistochemical perspective. Our goal is to characterize differential EpCAM immunohistochemistry (EpCAM-IHC) among HBs histotypes

Patients with NTRK-rearranged tumors can be now treated using anti-TRK–targeted therapies making NTRK testing important for treatment choices in patients with advanced cancers. Pan-TRK immunohistochemistry (IHC) could be a valuable premolecular screening strategy in this field. The choice of 1 IHC method or another requires to investigate for intermethod comparison. A high frequency of pan-TRK positive

The breast is a rare site for metastases, and their molecular characteristics have not been studied yet. Intrinsic molecular genetics, cancer characteristics, and breast tissue immune responses in diverse metastases to the breast have not been previously studied. We identified 64 patients with cancers metastatic to the breast: 51 carcinomas and 13 melanomas. Programmed death ligand 1 (PD-L1), steroid

Introduction:  Overexpression of the mesenchymal-epithelial transition (MET) receptor, a receptor tyrosine kinase, can propel the growth of cancer cells and portends poor prognoses for patients with lung cancer. Evaluation of MET by immunohistochemistry is challenging, with MET protein overexpression varying from 20% to 80% between lung cancer cohorts. Clinical trials using MET protein expression to

The present study aimed to investigate the expression levels and clinical significance of the calcineurin B homologous protein 2 (CHP2) in non–small cell lung cancer (NSCLC), and to study its effects on biological characteristics of NSCLC cells. Tumor and adjacent samples were collected from 196 NSCLC patients. Western blot analysis was used to detect the expression levels of the CHP2 in 8 pairs of

Clinical guidelines state that neoadjuvant chemotherapy should be administered before surgery in muscle invasive urinary bladder small cell neuroendocrine carcinoma. Recently described marker insulinoma-associated protein 1 (INSM1) has been reported to be sensitive and specific for neuroendocrine differentiation, however, its efficacy in urinary tract small cell carcinoma is not well established. This

The protein p57 is encoded by CDKN1C. This gene is known to be paternally imprinted and maternally expressed in cytotrophoblasts and villous stromal cells. We present a method for evaluating p57 antibodies (Abs) in hydatidiform mole (HM) and demonstrate the results for 4 p57 Abs in various cell types. Five cases of complete HM, diploid with 2 paternal genome sets (CHM;PP), 5 cases of partial HM, triploid

Objectives:  The objective of this study was (a) to identify, by computer processing of digitized images of hematoxylin and eosin (H&E)-stained biopsy material of the cervix, differences in the structure of nuclei between high-risk (HR) and low-risk (LR) human papillomavirus virus (HPV) types and (b) to assess the HPV risk type by designing a decision-support system (DSS). Materials and Methods:  Clinical

Background:  Metastatic melanoma in sentinel lymph nodes is often elusive to detect with morphology alone. Per American Joint Committee on Cancer staging guidelines, a single atypical melanocyte in lymph node qualifies as metastasis, whether identified by morphology or immunohistochemistry, but single cell staining must be convincing. We propose that the use of a second immunohistochemical run performed

We present a case of synchronous renal cell carcinoma and urothelial carcinoma. Our case was a true collision tumor and both components were high grade. Metastasis to the adrenal gland by the urothelial carcinoma was observed. The morphologic impression was confirmed with GATA3 expression by the urothelial carcinoma component and PAX8 expression by the renal cell carcinoma component. We have reviewed

Primary diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) is an aggressive subtype of DLBCL with characteristic clinicopathologic features. Relapse outside the CNS involving extranodal locations has been found in a fraction of cases (16%). Here we describe a case of DLBCL arising in the CNS that relapsed 18 months after the initial diagnosis in the testis and bilateral adrenal

Angiomatoid fibrous histiocytoma (AFH) can be diagnostically difficult because of its varied histologic appearance and potential to occur at unusual sites. The identification of recurrent rearrangements (EWSR1-CREB1, EWSR1-ATF1, and FUS-ATF1) is a helpful diagnostic tool. Additional immunohistochemical markers in AFH could aid in restricting the differential diagnosis and selecting appropriate cases

Background:  Colorectal carcinomas (CC) are one of the most commonly diagnosed malignancies. Tumor budding (the histologic process of dissociation that occurs at the invasive margin of colorectal cancer), has significant prognostic implications, in that higher tumor budding is associated with adverse histopathologic and clinical outcomes. Because of this prognostic significance, more research is needed

Atypical polypoid adenomyoma (APA) is a rare uterine lesion constituted by atypical endometrioid glands, squamous morules, and myofibromatous stroma. We aimed to assess the immunophenotype of the 3 components of APA, with regard to its pathogenesis and its differential diagnosis. A systematic review was performed by searching electronic databases from their inception to January 2019 for immunohistochemical

It is not uncommon for the forensic pathologist to question whether a deceased person had experienced sepsis that could have either been the cause of or contributed to the person’s death. Often, the missing typical pathologic factors or lack of clinical and circumstantial information on the death render the autopsy of a sepsis-related death a difficult task for the forensic pathologist. Several authors

Chronic inflammation is a major risk factor underlying aging and age-associated diseases. It impairs normal lipid accumulation, adipose tissue function, and mitochondrial function, which eventually lead to insulin resistance. Peroxisome proliferator-activated receptors (PPARs) critically regulate gluconeogenesis, lipid metabolism, and the lipid absorption and breakdown process, and PPAR activity decreases

Mesonephric carcinoma is a rare gynecologic neoplasm commonly mistaken for clear cell carcinoma, because of their overlapping morphologic features. Both tumors are negative for estrogen receptor and p16, magnifying this diagnostic dilemma. Recently, hepatocyte nuclear factor-1 beta (HNF-1β), a marker for clear cell carcinoma, has also been shown to be positive in mesonephric carcinomas. Other more

The p21-activated kinase (PAK) family of serine/threonine kinases plays a pivotal role in various human tumors, as supported by our previous report on the overexpressed PAK isoforms in non–small cell lung cancer (NSCLC). To better understand the role of PAKs in tumorigenesis, the authors examined PAK1 expression patterns and its significance in NSCLC. It was demonstrated by immunohistochemical staining

Aquaporin 3 (AQP3) serves as a water and glycerol transporter facilitating epithelial cell hydration. Recently, the involvement of AQP3 in cancers has been reported. However, the immunohistochemical expression of AQP3 in carcinomas remains controversial. We hypothesized that differences in aquaporin 3 antigen recognition (AQP3 AR) may influence their expressions. Thus, our study aimed to assess the

Before 2013, the diagnosis of about 30% to 45% cases of primary myelofibrosis (PMF) and essential thrombocythemia (ET) posed a diagnostic difficulty because of the missing reliable clonal marker. Calreticulin (CALR) mutation was identified as a recurrent mutation in about 60% to 88% of JAK2/MPL-negative PMF and ET. Molecular methods like Sanger sequencing and polymerase chain reaction (PCR) are considered

Angiomatoid fibrous histiocytoma (AFH) is a rarely metastasizing neoplasm that typically occurs in the deep dermis and subcutis of the extremities of young patients, characterized by a t(2;22) translocation involving EWSR1 and CREB1. Because of its distinctive histologic features, the diagnosis of AFH is generally straightforward, although the immunohistochemistry (IHC) findings are relatively nonspecific

Chloride channel calcium-activated (CLCA) genes encode regulators for chloride transport across the cell membrane. As for cancer development, some CLCA genes are considered putative tumor suppressor genes. The aim of this study was to explore whether CLCA4 gene would have mutations in its nucleotide repeats in colorectal cancer (CRC). In a public database, we found that CLCA4 gene had mononucleotide

NUT midline carcinoma (NMC) is a rare, aggressive poorly differentiated carcinoma genetically defined by NUTM1 gene rearrangement. The purpose of this study was to determine the tumor mutational burden (TMB) and the expression of immunohistochemical (IHC) markers in NMCs that are generally used to identify patients that might benefit from checkpoint immunotherapy. Three cases in a 39-year-old male

Myeloid sarcoma (MS) is defined as an extramedullary mass-forming lesion composed of immature myeloid cells. It is a rare but well-known manifestation of acute myeloid leukemia. Pediatrics testicular MS may pose a possible diagnostic challenge, an issue that is underscored in the few testicular pediatric MS cases reported in the literature. Herein, we report a series of 5 cases of pediatric testicular

We aim to evaluate the degree of agreement between immunohistochemistry (IHC) and flow cytometry (FC) in the diagnosis of malignant hematologic diseases, mainly lymphomas. A total of 260 bone marrow biopsies, 255 bone marrow aspirates, and 5 other suspensions of 260 patients used for diagnosis of a hematologic malignancy between 2009 and 2012 with both, IHC and FC, were retrospectively analyzed. Overall

Background:  Podoplanin is a transmembrane glycoprotein expressed on various normal or neoplastic cells. Some studies have shown that podoplanin promotes the migration and invasion of tumor cells. This study evaluated a podoplanin expression in Odontogenic Keratocysts (OKs) associated or not associated with Nevoid Basal Cell Carcinoma Syndrome (NBCCS) and in Orthokeratinized Odontogenic Cysts (OOCs)

Breast carcinoma is a multifaceted-etiology malignancy. The presence of estrogen (ER), progesterone (PR), and HER2 (human epidermal growth factor receptor 2) receptors in breast carcinoma tissue has therapeutic implications. Recent studies indicate that pineal hormone melatonin by its receptor melatonin 1 (MT1) also influences the development and growth of breast cancer cells. The aim of this cross-sectional

Extramammary Paget disease (EMPD) often involves apocrine gland-bearing locations including vulva and perianal area. EMPD of the scrotum is rare. Twenty patients were identified from the pathology files of 4 institutions between 2000 and 2018. Patients were 63- to 87-year-old (mean: 73 y) with a history of symptoms of between 4 months and 10 years. Two patients had a history of prostate cancer. Follow-up

“Special AT-rich sequence-binding protein-1” (SATB1) is a global genome organizer and is found to have effects on carcinogenesis and progression of various malignancies including colorectal carcinoma (CRC). We aimed to investigate the expression of SATB1 in CRC and colorectal adenomatous polyps (CAP), the correlation between clinicopathologic parameters, and overall survival. We examined 227 CRCs and

Molecular subtyping of medulloblastoma (MB) has become increasingly important for prognosis and management. Typically this involves detailed molecular genetic testing which may not be available in all centers. The purpose of the present study was to find a simplified approach to assign molecular subtypes of MB for routine use in centers with more limited resources. The molecular subtypes of MBs from

Ubiquitously transcribed tetratricopeptide repeat, X chromosome (UTX) is involved in the epigenetic regulation. A previous mouse xenograft study revealed that UTX knockdown is associated with downregulated expression of matrix metalloproteinase-11 (MMP-11). The authors investigated 224 cases of breast cancer from Kangbuk Samsung Medical Center between 2000 and 2005. Nuclear UTX and cytoplasmic MMP-11

Surrogate molecular classification identifies different subtypes of invasive breast carcinoma on the basis of their immunohistochemical markers. The purpose of the study is to verify whether the immunohistochemical markers and surrogate molecular subtypes can be correctly assessed on the core needle biopsy (CNB) when compared with the corresponding surgical excision (SE), with or without neoadjuvant

PAX8 is a specific marker for kidney, ovarian, and thyroid tissue. Antibody-dependent cross-reactivity for PAX8 has been reported in mesothelial, pancreatic, and B-cell proliferations. We recently described antibody clone-dependent aberrant PAX8 expression in breast cancer. In this study we systematically analyze PAX8 expression in breast cancer on whole tissue sections, using MRQ50 and BC12 PAX8 monoclonal

Many disorders of the central nervous system are characterized by both axonal pathology and demyelination. In assessing this concurrent pathology, techniques for staining axons or myelin are frequently used separately. Here we report the development of a combined immunohistochemical and tinctorial staining technique in which we have modified the Luxol fast blue myelin stain to be used in conjunction

This paper is number 7 in a series developed through a partnership between ISIMM and NordiQC with the purpose of reporting research assessing the performance characteristics of immunoassays in an external proficiency testing program.

Atypical teratoid/rhabdoid tumors (AT/RT) are highly aggressive malignant primitive neoplasms that commonly occur in children younger than 2 years of age. The prognosis is generally dismal with a median survival time of <1 year. The majority of AT/RT occur in the posterior fossa and less frequently the supratentorium. Primary pediatric spinal AT/RT are exceedingly rare and only 15 cases have been reported

Introduction:  This systematic review has the purpose to characterize the accuracy of chromogenic in situ hybridization (CISH) and silver in situ hybridization (SISH), in comparison to fluorescence in situ hybridization (FISH) in the identification of human epidermal growth factor receptor-2 (HER2) overexpression and to inform decisions about test selection. Materials and Methods:  We searched MEDLINE

The utility of prognostic and predictive immunohistochemistry biomarkers in the context of cancer is plagued by inconsistent interpretation of results which can lead to poor rates of adoption or inappropriate use of novel therapeutic strategies. To monitor immunohistochemistry assay performance, a new on-slide control motif, Immunohistochemistry Critical Assay Performance Controls (ICAPC) was developed

With immunohistochemical (IHC) staining increasingly being used to guide clinical decisions, variability in staining quality and reproducibility are becoming essential factors in generating diagnoses using IHC tissue preparations. The current study tested a method to track and quantify the interrun, intrarun, and intersite variability of IHC staining intensity. Our hypothesis was that staining precision

Biomarker analyses have become mandatory for treatment choices in patients with advanced non–small cell lung cancers. PD-L1 expression for immunotherapy as well as oncogenic molecular alterations for targeted therapies must be analyzed in tumor samples. Intersample heterogeneity may cause dilemmas in treatment choices when faced with discrepant biomarker results. We led a retrospective study evaluating

Background:  Simian virus 40 (SV40)-contaminated polio vaccine was accidentally administered to about one-third of the UK population receiving polio vaccines between 1956 and 1962. SV40 was subsequently demonstrated to be a carcinogenic virus in experimental and animal models. Since then, the SV40 oncogenic protein large T antigen (SV40 Tag) has been shown to cause malignant transformation of asbestos-treated

IgG4-related ophthalmic disease (IgG4-ROD) is a rare inflammatory disorder often refractory to corticosteroids and prone to recurrence. IgG4-ROD may frequently lack the characteristic histopathological features seen in other organs. Thus, the criteria for diagnosis of IgG4-ROD relies on elevated IgG4 cells seen on biopsied tissue. Proposed threshold levels of IgG4 to diagnose IgG4-ROD are currently

Endometrial cancer is one of the most common gynecologic malignancies worldwide. Only 2 agents have been approved by Food and Drug Administration for endometrial cancer since 1971. There is a need to identify molecular targets to treat advanced endometrial cancer. The receptor for hyaluronic acid–mediated motility (RHAMM) is upregulated in various types of cancer. Here, we aimed to determine the clinical

GATA3 is a transcription factor involved in the development and differentiation of lymphocytes, breast, and hair follicles. The protein is a useful immunohistochemical (IHC) marker for supporting diagnoses of breast or urothelial carcinoma. This can be especially helpful in metastatic neoplasms to help delineate site of origin. GATA3 is also reportedly positive in a percentage of pancreatic ductal

Hepatocellular adenomas (HCAs) often pursue an innocuous clinical course. Recent work has elucidated important subtypes of HCA and biomarkers to identify them, including HCA at an increased risk for malignant transformation. Another key complication of HCAs is the risk of spontaneous tumoral hemorrhage, which may be life-threatening. Identification of a predictive biomarker for this clinical complication

Thyroid transcription factor 1 (TTF-1) is an immunohistochemical marker in the identification of lung and thyroid tumors. However, positive labelling for TTF-1 can occur in tumors from other sites, and this can result in misdiagnosis if only a limited panel of antibodies is used. We assessed the frequency of expression of 3 TTF-1 antibody clones, namely, 8G7G3/1, SPT24, and SP141 on a tissue microarray