Programmed Death Ligand-1 and Tumor Mutation Burden Testing of Patients With Lung Cancer for Selection of Immune Checkpoint Inhibitor Therapies: Guideline From the College of American Pathologists, Association for Molecular Pathology, International Association for the Study of Lung Cancer, Pulmonary Pathology Society, and LUNGevity Foundation.

Context.—: Rapid advancements in the understanding and manipulation of tumor-immune interactions have led to the approval of immune therapies for patients with non-small cell lung cancer. Certain immune checkpoint inhibitor therapies require the use of companion diagnostics, but methodologic variability has led to uncertainty around test selection and implementation in practice.

Combining Panitumumab With Anti-PD-1 Antibody in Cutaneous Squamous Cell Carcinoma of the Head and Neck After Inadequate Response to Anti-PD-1 Antibody Alone.

Anti-epidermal growth factor receptor (EGFR) antibodies and anti-programmed cell death 1 protein (PD-1) antibodies have been used separately to treat metastatic cutaneous squamous cell carcinoma (cSCC). While two anti-EGFR antibodies have similar clinical activity, cetuximab is administered weekly, whereas panitumumab is administered every two weeks. This report details findings using panitumumab in combination with anti-PD-1 antibody in patients with relapsed refractory cSCC.

Utility and Limitations of Albumin mRNA In Situ Hybridization Detection in the Diagnosis of Hepatobiliary Lesions and Metastatic Carcinoma to the Liver.

Albumin messenger RNA (mRNA) in situ hybridization is a sensitive and specific biomarker for hepatocellular carcinoma (HCC). Intrahepatic cholangiocarcinoma (ICC) shows variable sensitivity, whereas extrahepatic cholangiocarcinoma (ECC) and metastatic carcinoma are generally negative. We studied the clinical utility and limitations of albumin mRNA detection in a cohort of HCCs, ICCs, ECCs, bile duct adenomas, bile duct hamartomas, and metastatic carcinomas to the liver; and investigated the variability in sensitivity observed for this biomarker in ICCs.

Quantitative assessment of PD-L1 as an analyte in immunohistochemistry diagnostic assays using a standardized cell line tissue microarray.

Programmed death 1 ligand 1 (PD-L1) Immunohistochemistry (IHC) is the key FDA-approved predictive marker to identify responders to anti-PD1 axis drugs. Multiple PD-L1 IHC assays with various antibodies and cut points have been used in clinical trials across tumor types. Comparative performance characteristics of these assays have been extensively studied qualitatively but not quantitatively.

Concurrent Eosinophilic Solid and Cystic Renal Cell Carcinoma and Angiomyolipoma With Epithelial Cysts in the Setting of Tuberous Sclerosis Complex: A Rare Synchronous Occurrence of 2 Distinct Entities.

Eosinophilic solid and cystic renal cell carcinoma (ESCRCC) is a recently described distinct renal neoplasm known to occur almost exclusively in female patients with or without tuberous sclerosis complex (TSC). We report a case of ESCRCC with 2 synchronous angiomyolipomas, including 1 angiomyolipoma with epithelial cysts (AMLEC), a rare cystic variant of AML that typically arises sporadically in the absence of TSC, in a 46-year-old woman with TSC. Besides additional copy number alterations identified in ESCRCC via molecular karyotyping, we also report a unique histologic feature of TSC-associated ESCRCC previously not described in detail, with formation of semicircular multinucleated neoplastic giant cells engulfing an additional intact neoplastic cell, simulating emperipolesis.

Cutaneous histoplasmosis with prominent parasitization of epidermal keratinocytes: report of a case.

Disseminated histoplasmosis most commonly occurs in immunosuppressed individuals and involves the skin in approximately 6% of patients. Cutaneous histoplasmosis with an intraepithelial-predominant distribution has not been described. A 47-year-old man was admitted to our institution with fever and vancomycin-resistant enterococcal bacteremia.

IMP3 Immunoreactivity is More Sensitive Than AMACR in Detecting Dysplastic Epithelium and Early Adenocarcinoma in Barrett Esophagus.

Context: α-methylacyl coenzyme A racemase (AMACR) and insulin-like growth factor-II mRNA-binding protein 3 (IMP3) are 2 markers helpful in detecting difficult cases of dysplasia in Barrett esophagus (BE). However, no comparison studies have been performed to assess their performance in the same patient population.

Objectives: The aim of our study was to compare the immunohistochemical expression of IMP3 and AMACR in dysplastic lesions and early adenocarcinoma (EAC) arising in BE and evaluate their sensitivity and specificity.

Expression and utility of IMP3 in the differential diagnosis of atypical glandular cells and adenocarcinoma in liquid-based cervical cytology.

Background: Atypical glandular cell (AGC) interpretation in gynecological cytopathology presents many diagnostic challenges. We evaluated the expression of IMP3 in liquid-based cervical cytology and its utility in differentiating premalignant/malignant glandular lesions from benign/reactive processes. Additionally, we tried to determine whether IMP3 may be useful in differentiating among the types of uterine adenocarcinomas.

Cokeromyces recurvatus identified in lung biopsy: case report of a non-pathogenic fungus, highlighting its potential histologic mimics.

We report a case of aspiration in a patient with gastric outlet obstruction due to pancreatic adenocarcinoma, in which three large yeasts were identified on tissue biopsy of the lung infiltrate. The histologic sections of the yeasts showed densely eosinophilic, round to oval, thick-walled structures with frayed borders and intra-cystic bluish inclusions. There was a background of mixed neutrophilic and eosinophilic infiltrate along with focal tissue necrosis.

Role of lymphovascular invasion and immunohistochemical expression of IMP3 in the risk stratification of superficially invasive pT1 esophageal adenocarcinoma.

Background: A problem in the management of patients with Barrett's esophagus-related pT1 esophageal adenocarcinoma is to distinguish those who should be treated conservatively (endoscopic mucosal resection and/or radiofrequency ablation) from those who require esophago-gastrectomy. Recently, lymphovascular invasion (LVI) has emerged as one of the best predictors of regional lymph node metastasis (LNM) and recurrence-free survival (RFS) in pT1 EAC. However, LVI may be underestimated, both because of interobserver variability and incomplete sampling.

The utility of PAX8 and IMP3 immunohistochemical stains in the differential diagnosis of benign, premalignant, and malignant endocervical glandular lesions.

Unlabelled: Glandular lesions of the endocervix can be diagnostically challenging and occasionally the differential diagnosis includes endocervical adenocarcinoma in situ (EC AIS) and well-differentiated endocervical adenocarcinoma (ECA). PAX8 and IMP3 are two markers which have not been well studied in the endocervix. Our aim was to evaluate their immunohistochemical (IHC) expression in benign and malignant endocervical glandular lesions as well as to compare them to the traditionally used panel (Ki-67, p16, CEA).

Immune evasion and recognition of the syphilis spirochete in blood and skin of secondary syphilis patients: two immunologically distinct compartments.

Background: The clinical syndrome associated with secondary syphilis (SS) reflects the propensity of Treponema pallidum (Tp) to escape immune recognition while simultaneously inducing inflammation.

Methods: To better understand the duality of immune evasion and immune recognition in human syphilis, herein we used a combination of flow cytometry, immunohistochemistry (IHC), and transcriptional profiling to study the immune response in the blood and skin of 27 HIV(-) SS patients in relation to spirochetal burdens. Ex vivo opsonophagocytosis assays using human syphilitic sera (HSS) were performed to model spirochete-monocyte/macrophage interactions in vivo.

IMP3 immunocytochemical staining increases sensitivity in the routine cytologic evaluation of biliary brush specimens.

Biliary brush cytology is an important diagnostic tool in the evaluation of biliary strictures. Here, we evaluated 64 patients with biliary strictures who underwent endoscopic retrograde cholangiopancreatography with bile duct brushings. We assessed the utility of combining routine Papanicolaou-stained cytologic evaluation with immunocytochemical expression of insulin-like growth factor mRNA-binding protein-3 (IMP3).

Human herpesvirus-6 in patients with Crohn's disease.

Human herpesvirus-6 (HHV-6) infections are usually asymptomatic reactivations in immunocompetent persons, but may be severe in immunocompromised individuals. Although primary HHV-6 infection is mainly associated with roseola infantum, it has also been associated with gastroenteritis, diarrhea, and nausea in children. In this study, we investigated the potential role of HHV-6 in Crohn's disease (CD).

Consensus recommendations on estrogen receptor testing in breast cancer by immunohistochemistry.

Estrogen receptor (ER) status in breast cancer is currently the most important predictive biomarker that determines breast cancer prognosis after treatment with endocrine therapy. Although immunohistochemistry has been widely viewed as the gold standard methodology for ER testing in breast cancer, lack of standardized procedures, and lack of regulatory adherence to testing guidelines has resulted in high rates of "false-negative" results worldwide. Standardized testing is only possible after all aspects of ER testing--preanalytical, analytical, and postanalytical, have been closely controlled.

KOC (K homology domain containing protein overexpressed in cancer) and S100A4-protein immunoreactivity improves the diagnostic sensitivity of biliary brushing cytology for diagnosing pancreaticobiliary malignancies.

Biliary tract brush cytology is one of the favored methods of evaluating lesions of the pancreatobiliary tract. However, although its specificity has been reported to be high (91-100%), the sensitivity is lower (30-88%). In this study we applied KOC and S100A4 protein immunocytochemistry to assess their potential use as adjunct markers in differentiating benign from malignant cells, and improve the diagnostic sensitivity of this method for pancreatobiliary malignancies.

Utility of glypican-3 in differentiating hepatocellular carcinoma from other primary and metastatic lesions in FNA of the liver: an immunocytochemical study.

We evaluated the immunocytochemical expression of GPC3 in archival material obtained from fine needle aspiration of hepatic lesions to assess the sensitivity and specificity of this marker in cytological material and its potential diagnostic utility in differentiating hepatocellular carcinoma (HCC) from other primary benign or malignant hepatic tumors and from metastatic lesions in the liver. Forty-nine FNAs of the liver obtained between January 2000 and June 2006 were identified from our cytology files. Cytological diagnoses (confirmed by tissue diagnosis and/or clinical follow-up) included: 7 adenomas, 1 focal nodular hyperplasia (FNH), 24 HCCs, and 17 metastatic tumors.

Human epidermal growth factor receptor-2 and estrogen receptor expression, a demonstration project using the residual tissue repository of the Surveillance, Epidemiology, and End Results (SEER) program.

Background: In 2001, the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program established Residual Tissue Repositories (RTR) in the Hawaii, Iowa, and Los Angeles Tumor Registries to collect discarded tissue blocks from pathologic laboratories within their catchment areas. To validate the utility of the RTR for supplementing SEER's central database, we assessed human epidermal growth factor receptor-2 (HER2) and estrogen receptor expression (ER) in a demonstration project.

Materials: Using a prepared set of tissue microarrays (TMAs) residing in the Hawaii Tumor Registry (HTR), we performed standard immunohistochemistry.

True intranuclear inclusions in a melanocytic nevus: report of a case and review of the literature.

Melanocytic tumors commonly show intranuclear pseudo-inclusions or cytoplasmic invaginations within the nuclei of melanocytes. However, true intranuclear inclusions have rarely been described in melanocytic nevus cells. Herein, we describe the histologic, immunohistochemical and ultrastructural features of an additional case of an intradermal melanocytic nevus with true intranuclear inclusions.

Hormonal markers in breast cancer: coexpression, relationship with pathologic characteristics, and risk factor associations in a population-based study.

The objective of this study was to evaluate the coexpression patterns of hormonal markers in breast cancer tissue and their relationship with pathologic characteristics and epidemiologic risk factors. We evaluated the expression of 17 markers by immunohistochemistry in 842 invasive breast carcinomas collected in a population-based case-control study conducted in Poland. Based on marker correlations, factor analysis identified four major coexpression patterns (factors): "nuclear receptor factor" [estrogen receptor (ER)-alpha, progesterone receptor, androgen receptor, cyclin D1, and aromatase], "estrogen metabolism/ER-beta factor" (ER-beta, peroxisome proliferator-activated receptor-gamma, steroid sulfatase, estrogen sulfonotransferase, and cytochrome P450 1B1), "HER2 factor" (human epidermal growth factor receptor 2, E-cadherin, cyclooxygenase-2, aromatase, steroid sulfatase), and "proliferation factor" (cytokeratin 5, cytokeratin 5/6, epidermal growth factor receptor, P53).

Expression of K homology domain containing protein overexpressed in cancer in pancreatic FNA for diagnosing adenocarcinoma of pancreas.

We evaluated the immunocytochemical (ICC) expression of K homology domain containing protein overexpressed in cancer (KOC) in pancreatic endoscopic ultrasound-guided fine needle aspirates (EUS-FNAs) to assess its potential use as an adjunct in differentiating nonneoplastic (GI epithelium) and benign neoplastic epithelia (benign epithelial pancreatic neoplasms) from pancreatic adenocarcinoma cells. Forty-eight cases of EUS-FNAs with histological and/or clinical follow-up data were selected for this study. Alcohol-fixed and PAP-stained slides were stained with monoclonal antibody to KOC/L523S (clone 69.