Molecular-Guided Therapy for Melanoma in Canada: Overview of Current Practices and Recommendations.

The emergence of pathologist-driven molecular reflex testing for tumoural biomarkers is a significant advancement in cancer diagnostics, facilitating targeted cancer therapy for our patients. Based on our experience, the Canadian landscape of pathologist-driven reflex biomarker testing for melanoma lacks standardization and is plagued by a lack of awareness by pathologists and clinicians. This paper comprehensively examines the approaches to reflex biomarker testing for melanoma patients across Canada, highlighting the regional variations in the criteria for initiating molecular testing, the biomarkers tested, and the molecular techniques employed.

Survival of Patients With Head and Neck Merkel Cell Cancer: Findings From the Pan-Canadian Merkel Cell Cancer Collaborative.

Importance: Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma. Due to its relatively low incidence and limited prospective trials, current recommendations are guided by historical single-institution retrospective studies.

Objective: To evaluate the overall survival (OS) of patients in Canada with head and neck MCC (HNMCC) according to American Joint Committee on Cancer 8th edition staging and treatment modalities.

PRAME and LEF1 in Combined Deep Penetrating Nevus and Combined Blue Nevus: Utility and Pitfalls.

Deep penetrating nevi (DPN), particularly those showing combined features, or combined deep penetrating nevi (CDPN), may show histopathological resemblance to blue nevus (BN) and melanoma. Preferentially Expressed Antigen in MElanoma (PRAME) is a marker that helps distinguish melanoma from benign melanocytic lesions. Lymphoid enhancer-binding factor 1 (LEF1) has been proposed to be used in conjunction with β-catenin for diagnosis of DPN.

SOX11 Is an Effective Discriminatory Marker, When Used in Conjunction With CK20 and TTF1, for Merkel Cell Carcinoma: Comparative Analysis of SOX11, CK20, PAX5, and TTF1 Expression in Merkel Cell Carcinoma and Pulmonary Small Cell Carcinoma.

Context.—: Distinction between Merkel cell carcinoma (MCC) and pulmonary small cell carcinoma (PSmCC) can be challenging, even with the aid of immunohistochemistry (IHC) analysis of CK20 and TTF1, as these tumors occasionally lack classic immunophenotypes (CK20+/TTF1- in MCC and CK20-/TTF1+ in PSmCC).

Objective.

Ductal differentiation: A rare phenomenon in Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine carcinoma that may occasionally present divergent histopathologic features. We present two cases of MCC demonstrating ductal differentiation, one on the lower lip of an 81-year-old man and another on the right forearm of a 67-year-old man. The histopathologic features included TTF1-negative, infiltrative, high-grade basaloid tumor with paranuclear punctate positivity for cytokeratin (CK) 20 and synaptophysin.

Diagnostic utility of PRAME expression by immunohistochemistry in subungual and non-subungual acral melanocytic lesions.

Background: The immunohistochemical (IHC) marker PReferentially expressed Antigen in MElanoma (PRAME) has shown promise in the diagnosis of melanocytic lesions. A few studies have investigated PRAME IHC expression in acral melanomas, but PRAME expression in subungual melanomas is largely unknown. We evaluated the utility of PRAME IHC expression in distinguishing subungual melanomas (SUM) and non-subungual acral melanomas (AM) from acral nevi (AN).

Amyloid deposition with a granulomatous reaction in a resection specimen: A clue for a pre-existing Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is an aggressive, highly metastatic, cutaneous neuroendocrine malignancy with poor prognosis. Here, we describe a MCC excision specimen with a rare case of tumor-associated amyloid deposition in the absence of residual tumor cells. A 72-year-old man presented with a lesion of 5-6 months' duration on his left elbow, clinically thought to be a ganglion cyst.

Filaggrin expression via immunohistochemistry in basal cell carcinoma and squamous cell carcinoma.

Background: Filaggrin is a protein integral to the structure and function of the epidermis. Filaggrin (FLG) loss-of-function (LOF) mutations are common and increase the risk of developing atopic dermatitis (AD) and ichthyosis vulgaris (IV). Epidemiologic data suggest a link between skin cancer and AD.

Characterizing and classifying neuroendocrine neoplasms through microRNA sequencing and data mining.

Neuroendocrine neoplasms (NENs) are clinically diverse and incompletely characterized cancers that are challenging to classify. MicroRNAs (miRNAs) are small regulatory RNAs that can be used to classify cancers. Recently, a morphology-based classification framework for evaluating NENs from different anatomical sites was proposed by experts, with the requirement of improved molecular data integration.

Navigated tissue characterization during skin cancer surgery.

Purpose: Basal cell carcinoma (BCC) is the most commonly diagnosed skin cancer and is treated by surgical resection. Incomplete tumor removal requires surgical revision, leading to significant healthcare costs and impaired cosmesis. We investigated the clinical feasibility of a surgical navigation system for BCC surgery, based on molecular tissue characterization using rapid evaporative ionization mass spectrometry (REIMS).

Perioperative margin detection in basal cell carcinoma using a deep learning framework: a feasibility study.

Purpose: Basal cell carcinoma (BCC) is the most commonly diagnosed cancer and the number of diagnosis is growing worldwide due to increased exposure to solar radiation and the aging population. Reduction of positive margin rates when removing BCC leads to fewer revision surgeries and consequently lower health care costs, improved cosmetic outcomes and better patient care. In this study, we propose the first use of a perioperative mass spectrometry technology (iKnife) along with a deep learning framework for detection of BCC signatures from tissue burns.

Neutrophil recruitment and function in endometriosis patients and a syngeneic murine model.

Endometriosis is a chronic inflammatory, gynecological disease characterized by the presence of endometrial-like tissue lesions outside of the uterus. Neutrophils are elevated in the systemic circulation and peritoneal fluid of endometriosis patients; however, whether and how neutrophils contribute to endometriosis pathophysiology remain poorly understood. With emerging roles for neutrophils in chronic and sterile inflammatory conditions, we sought to provide in-depth characterization of neutrophil involvement in endometriosis.

Generational Expression of Muir-Torre Syndrome in a Canadian Family.

Muir-Torre syndrome (MTS) is a rare autosomal dominant inherited genodermatosis that is considered to be a phenotypic subtype of hereditary nonpolyposis colorectal cancer (HNPCC), commonly referred to as Lynch syndrome. We describe the clinical course of a 57-year-old female patient with MTS. She has a confirmed mutation.

Co- and post-transcriptional regulation of Rbm5 and Rbm10 in mouse cells as evidenced by tissue-specific, developmental and disease-associated variation of splice variant and protein expression levels.

Background: Expression and function of the two RNA binding proteins and regulators of alternative splicing, RBM5 and RBM10, have largely been studied in human tissue and cell lines. The objective of the study described herein was to examine their expression in mouse tissue, in order to lay the framework for comprehensive functional studies using mouse models.

Methods: All RNA variants of Rbm5 and Rbm10 were examined in a range of normal primary mouse tissues.

Combined therapeutic use of oral alitretinoin and narrowband ultraviolet-B therapy in the treatment of hailey-hailey disease.

Hailey-Hailey disease (HHD) is a chronic familial bullous disease characterized by recurrent blisters and erosions typically at friction-prone areas of the body accompanied by acantholysis upon histologic examination. There are a number of therapies used in the management of HHD. Its symptoms have been effectively treated with antimicrobial therapies, corticosteroids and other agents such as cyclosporine and prednisone.