Correlation of melanoma gene expression score with clinical outcomes on a series of melanocytic lesions.

A 23-gene expression signature was recently developed as an adjunct to histopathology to differentiate melanocytic nevi from melanoma. The current study correlated the gene expression signature scores to actual clinical outcomes in cases from the first validation study. RNA was extracted from 127 archival formalin-fixed paraffin-embedded tissue sections of melanocytic lesions.

Coordination of Rad1-Rad10 interactions with Msh2-Msh3, Saw1 and RPA is essential for functional 3' non-homologous tail removal.

Double strand DNA break repair (DSBR) comprises multiple pathways. A subset of DSBR pathways, including single strand annealing, involve intermediates with 3' non-homologous tails that must be removed to complete repair. In Saccharomyces cerevisiae, Rad1-Rad10 is the structure-specific endonuclease that cleaves the tails in 3' non-homologous tail removal (3' NHTR).

Significance of epidermal mitoses in challenging melanocytic proliferations.

Background: Accurate diagnosis of melanoma remains histologically challenging. Dermal mitoses support malignancy, but are only occasionally seen in melanomas. As melanomagenesis is thought to begin at the dermal-epidermal junction, we investigated the significance of epidermal melanocytic mitoses (EMM) in a spectrum of lesions with molecular characterization.

Superficial malignant peripheral nerve sheath tumor with overlying intradermal melanocytic nevus mimicking spindle cell melanoma.

Malignant peripheral nerve sheath tumors are rare soft tissue sarcomas with histological and immunohistochemical similarities to spindle cell melanoma. Although spindle cell melanoma is significantly more common, both tumors may express S100 and lack staining for HMB-45, Melan-A or MITF. Here we present a case of superficial malignant peripheral nerve sheath tumor with diffuse S100 positivity arising in a subtle neurofibroma in close proximity to an intradermal melanocytic nevus.

Stenotrophomonas maltophila cellulitis in an immunocompromised patient presenting with purpura, diagnosed on skin biopsy.

Stenotrophomas maltophilia is an opportunistic Gram-negative bacillus and an important cause of nosocomial infections, particularly in immunosuppressed individuals. Although infections with this organism are most often in the form of pneumonia, bacteremia and endocarditis, awareness of the impact of S. maltophilia skin infections has been increasing.

MET and PTEN gene copy numbers and Ki-67 protein expression associate with pathologic complete response in ERBB2-positive breast carcinoma patients treated with neoadjuvant trastuzumab-based therapy.

Background: Pathologic complete response (pCR) after neoadjuvant chemotherapy for breast cancer is associated with improved prognosis in aggressive tumor subtypes, including ERBB2- positive tumors. Recent adoption of pCR as a surrogate endpoint for clinical trials in early stage breast cancer in the neoadjuvant setting highlights the need for biomarkers that, alone or in combination, help predict the likelihood of response to treatment.

Methods: Biopsy specimens from 29 patients with invasive ductal carcinoma treated with trastuzumab-based therapy prior to definitive resection and pathologic staging were evaluated by dual color bright field in situ hybridization (dual ISH) using probes for MET, TOP2A, PTEN, and PIK3CA genes, each paired with centromeric probes to their respective chromosomes (chromosomes 7, 17, 10, and 3).

Comparison between melanoma gene expression score and fluorescence in situ hybridization for the classification of melanocytic lesions.

Melanoma accounts for most skin cancer-related deaths and has an increasing incidence. Accurate diagnosis and distinction from atypical nevi can be at times difficult using light microscopy alone. Fluorescence in situ hybridization (FISH) and melanoma gene expression score (myPath, Myriad Genetics) have emerged as ancillary tools to further aid in this differential diagnosis.

Genomic microarray analysis on formalin-fixed paraffin-embedded material for uveal melanoma prognostication.

Cytogenetic alterations are strong outcome prognosticators in uveal melanoma (UVM). Monosomy 3 (-3) and MYC amplification at 8q24 are commonly tested by fluorescence in situ hybridization (FISH). Alternatively, microarray analysis provides whole genome data, detecting partial chromosome loss, loss of heterozygosity (LOH), or abnormalities unrepresented by FISH probes.

Cytokeratin 20-negative Merkel cell carcinoma is infrequently associated with the Merkel cell polyomavirus.

Merkel cell carcinoma is a rare, highly aggressive cutaneous neuroendocrine carcinoma most commonly seen in sun-damaged skin. Histologically, the tumor consists of primitive round cells with fine chromatin and numerous mitoses. Immunohistochemical stains demonstrate expression of neuroendocrine markers.

Detection of immunoglobulin light-chain restriction in cutaneous B-cell lymphomas by ultrasensitive bright-field mRNA in situ hybridization.

Background: Detection of immunoglobulin light-chain restriction is important in the diagnosis of B-cell non-Hodgkin lymphoma (B-NHL). Flow-cytometry, commonly used to evaluate light-chain restriction, is impractical to be used in cutaneous specimens. Immunohistochemical and conventional chromogenic in situ hybridization (CISH) methods on formalin-fixed-paraffin-embedded (FFPE) tissue lack sufficient sensitivity to detect low-level light-chain expression in B-NHL without plasmacytic differentiation.

EGFR mutational genotyping of liquid based cytology samples obtained via fine needle aspiration (FNA) at endobronchial ultrasound of non-small cell lung cancer (NSCLC).

Objectives: Epidermal growth factor receptor (EGFR) gene mutation status should be determined in all patients with advanced, non-squamous non-small cell lung carcinoma (NSCLC) to guide targeted therapy with EGFR tyrosine kinase inhibitors. EGFR mutations are commonly tested by Sanger sequencing or allele specific polymerase chain reaction (ASPCR) on formalin-fixed paraffin-embedded (FFPE) samples including cell blocks (CB) that may fail due to absence of tumor cells. The cell pellet from cytology specimens obtained at the time of endobronchial guided ultrasound fine needle aspiration (EBUS FNA) (EBUS-TBNA, transbronchial needle aspiration) represents an alternative resource for additional tissue.

ALK status testing in non-small-cell lung carcinoma by FISH on ThinPrep slides with cytology material.

Introduction: Oncogenic anaplastic lymphoma kinase (ALK) gene rearrangements in non-small-cell lung carcinomas (NSCLC) provide the basis for targeted therapy with crizotinib and other specific ALK inhibitors. Treatment eligibility is conventionally determined by the Food and Drug Administration-approved companion diagnostic fluorescence in situ hybridization (FISH) assay on paraffin-embedded tissue (PET). On limited samples such as fine needle aspiration-derived cytoblocks, FISH for ALK is often uninformative.

High MET receptor expression but not gene amplification in ALK 2p23 rearrangement positive non-small-cell lung cancer.

Introduction: Overexpression of MET receptor tyrosine kinase and its ligand hepatocyte growth factor (HGF) and MET gene amplification have been well-documented in non-small-cell lung cancer (NSCLC). Activated MET signaling plays an important role in human cancer tumorigenesis, metastasis, and drug resistance. However, the deregulation of MET/HGF pathway in NSCLC harboring ALK gene rearrangement (ALK[+]), which is sensitive to dual ALK and MET inhibitor Crizotinib, has not been reported.

Ultrasensitive RNA in situ hybridization for detection of restricted clonal expression of low-abundance immunoglobulin light chain mRNA in B-cell lymphoproliferative disorders.

Objectives: To assess the feasibility of using a novel ultrasensitive bright-field in situ hybridization approach (BRISH) to evaluate κ and λ immunoglobulin messenger RNA (mRNA) expression in situ in B-cell non-Hodgkin lymphoma (NHL).

Methods: A series of 110 semiconsecutive clinical cases evaluated for lymphoma with historic flow cytometric (FCM) results were assessed with BRISH.

Results: BRISH light chain restriction (LCR) results were concordant with FCM in 108 (99%) of 109 evaluable cases.

HER4 expression status correlates with improved outcome in both neoadjuvant and adjuvant Trastuzumab treated invasive breast carcinoma.

Prognostic and predictive markers utilized in invasive breast carcinoma are limited and include ER, PR, Ki67, and ERBB2 (HER2). In the case of HER2, over-expression or amplification serves as eligibility for anti-HER2 based therapy, including trastuzumab (Herceptin®, Genentech). While clinical trials have shown trastuzumab improves overall survival and time to progression, an individual's response to anti-HER2 based therapy is highly variable.

ALK status testing in non-small cell lung carcinoma: correlation between ultrasensitive IHC and FISH.

ALK gene rearrangements in advanced non-small cell lung carcinomas (NSCLC) are an indication for targeted therapy with crizotinib. Fluorescence in situ hybridization (FISH) using a recently approved companion in vitro diagnostic class FISH system commonly assesses ALK status. More accessible IHC is challenged by low expression of ALK-fusion transcripts in NSCLC.

Role of Saw1 in Rad1/Rad10 complex assembly at recombination intermediates in budding yeast.

The Saccharomyces cerevisiae Rad1/Rad10 complex is a multifunctional, structure-specific endonuclease that processes UV-induced DNA lesions, recombination intermediates, and inter-strand DNA crosslinks. However, we do not know how Rad1/Rad10 recognizes these structurally distinct target molecules or how it is incorporated into the protein complexes capable of incising divergent substrates. Here, we have determined the order and hierarchy of assembly of the Rad1/Rad10 complex, Saw1, Slx4, and Msh2/Msh3 complex at a 3' tailed recombination intermediate.

From morphologic to molecular: established and emerging molecular diagnostics for breast carcinoma.

Diagnostics in the field of breast carcinoma are constantly evolving. The recent wave of molecular methodologies, both microscope and non-microscope based, have opened new ways to gain insight into this disease process and have moved clinical diagnostics closer to a 'personalized medicine' approach. In this review we highlight some of the advancements that laboratory medicine technology is making toward guiding the diagnosis, prognosis, and therapy selection for patients affected by breast carcinoma.

Replication fork stalling by bulky DNA damage: localization at active origins and checkpoint modulation.

The integrity of the genome is threatened by DNA damage that blocks the progression of replication forks. Little is known about the genomic locations of replication fork stalling, and its determinants and consequences in vivo. Here we show that bulky DNA damaging agents induce localized fork stalling at yeast replication origins, and that localized stalling is dependent on proximal origin activity and is modulated by the intra-S-phase checkpoint.

Small lymphocytic lymphoma obscuring microscopic tonsillar squamous cell carcinoma: an unknown occurrence with a known primary.

Head and neck squamous cell carcinoma (HNSCC) often presents with cervical lymph node metastases and at times the primary tumor cannot be identified despite extensive workup. Lymphoma is the second most common neoplasm in the head and neck region but is seldom synchronous with HNSCC and rarely involves regional mucosal sites. We report herein a rare occurrence of tonsillar involvement by small lymphocytic lymphoma (SLL) incidentally detected during the workup for a cervical lymph node SCC metastasis of a 52-year-old non-smoker male.

Multiple Rad5 activities mediate sister chromatid recombination to bypass DNA damage at stalled replication forks.

DNA damage that blocks replication is bypassed in order to complete chromosome duplication and preserve cell viability and genome stability. Rad5, a PCNA polyubiquitin ligase and DNA-dependent ATPase in yeast, is orthologous to putative tumor suppressors and controls error-free damage bypass by an unknown mechanism. To identify the mechanism in vivo, we investigated the roles of Rad5 and analyzed the DNA structures that form during damage bypass at site-specific stalled forks present at replication origins.