[Main Types of Cysts in Dermatopathology: Part 2]. / Principales tipos de quistes en dermatopatología: Parte 2.

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts.

Retrospective Case Series of Cocaine-Associated Plasma Cell Orificial Mucositis.

Importance: Plasma cell orificial mucositis (PCOM) associated with cocaine use is an emerging, rare condition that has become a concern in Spain in recent years. Limited knowledge exists regarding this novel condition. Objectives: To delineate the clinicopathologic characteristics of this emerging entity and establish a novel approach in the differential diagnosis of cocaine-associated lesions. Design, Setting, and Participants: A descriptive, retrospective, multicenter case series of 10 patients diagnosed with cocaine-associated PCOM was conducted in Spain from April 2020 to March 2023. Main Outcomes and Measures: Patient demographic, clinical, histopathologic, and treatment data were collected. Results: A total of 10 patients (6 [60%] male; median [range] age, 45.5 [36-66] years) presenting with exudative ulcerated plaques were identified for this study. The lesions had raised and erythematous edges over the nostril and a median (range) evolution time of 9 (2-24) months. Septal or palate perforations were observed in 4 (40%) of the patients. Biopsies revealed a dense inflammatory infiltrate of plasma cells in the dermis without atypia and with eosinophils. All patients reported recent cocaine use. Three urine tests detected cocaine but found no presence of amphetamines or opiates. Six patients improved with corticosteroid therapy. Up to 60% of patients were lost to follow-up. Conclusions and Relevance: This case series describes the clinicopathologic characteristics of PCOM, an emerging entity associated with cocaine use in Spain, and demonstrates a novel approach in the differential diagnosis of cocaine-associated lesions. To date, cocaine-associated skin lesions have been reported as neutrophilic dermatoses and vasculitis. The appearance of a plasma cell infiltrate changes what has been described in the medical literature so far. PCOM is a benign condition of unknown cause characterized by a proliferative polyclonal plasma cell infiltrate. A comprehensive differential diagnosis workup is required to reach this exclusionary diagnosis. Several irritants have been documented in cases of PCOM, and a hypersensitivity mechanism has been proposed. Since the initial report of cocaine-associated PCOM in Spain, its incidence has experienced a surge in the country. The cause of this phenomenon may be attributed to newly unidentified adulterants. The administration of corticosteroids and discontinuation of cocaine use are the sole treatments that have demonstrated efficacy. Clinicians should be vigilant regarding this emerging condition and conduct inquiries into cocaine use. Additional research is required to clarify the pathophysiology of this emerging condition.

[Main Types of Cysts in Dermatopathology: Part 1]. / Principales tipos de quistes en dermatopatología: parte 1.

Cystic structures represent one of the most common findings in dermatopathology. These encompass both cystic tumors and pseudocysts resulting from the accumulation of certain substances, such as mucin. In a two-part series (of which this is the first part), we have reviewed the principal types of cysts and pseudocysts that may be observed in cutaneous biopsies, examining their histopathological features and primary differential diagnoses. This first part encompasses infundibular cysts, eruptive dermoid cysts, pigmented follicular cysts, pilonidal cysts, tricholemmal cysts, milium cysts, hybrid cysts, bronchogenic cysts, as well as steatocystoma, hydrocystoma, and comedones.

Machine Learning Quantification of Intraepithelial Tumor-Infiltrating Lymphocytes as a Significant Prognostic Factor in High-Grade Serous Ovarian Carcinomas.

The prognostic and predictive role of tumor-infiltrating lymphocytes (TILs) has been demonstrated in various neoplasms. The few publications that have addressed this topic in high-grade serous ovarian carcinoma (HGSOC) have approached TIL quantification from a semiquantitative standpoint. Clinical correlation studies, therefore, need to be conducted based on more accurate TIL quantification. We created a machine learning system based on H&E-stained sections using 76 molecularly and clinically well-characterized advanced HGSOC. This system enabled immune cell classification. These immune parameters were subsequently correlated with overall survival (OS) and progression-free survival (PFI). An intense colonization of the tumor cords by TILs was associated with a better prognosis. Moreover, the multivariate analysis showed that the intraephitelial (ie) TILs concentration was an independent and favorable prognostic factor both for OS (p = 0.02) and PFI (p = 0.001). A synergistic effect between complete surgical cytoreduction and high levels of ieTILs was evidenced, both in terms of OS (p = 0.0005) and PFI (p = 0.0008). We consider that digital analysis with machine learning provided a more accurate TIL quantification in HGSOC. It has been demonstrated that ieTILs quantification in H&E-stained slides is an independent prognostic parameter. It is possible that intraepithelial TIL quantification could help identify candidate patients for immunotherapy.

Metanephric adenoma: molecular study and review of the literature.

INTRODUCTION: Metanephric adenoma (MA) is an uncommon benign tumor accounting for 0.2-0.7% of adult renal epithelial neoplasms. The clinical course is often indolent, but diagnosis should not be delayed since clinical symptoms (hematuria, fever, palpable abdominal mass, and flank pain) may be non-specific and overlap with those of a malign renal neoplasm. We report on 4 cases of AM, for which morphological and mutational analysis were performed. MATERIAL AND METHODS: Immunohistochemical staining was performed on sections cut from paraffin blocks to assess expression of WT1, vimentin, racemase, CK7, CD10 and RCC. Testing for the BRAF gene mutation V600 was carried out using real-time PCR (Cobas® 4800). RESULTS: In all four cases, tumors were visible as well-circumscribed, non-encapsulated masses located in the renal cortex and extending towards the medulla. At immunohistochemical examination, tumor cells stained negative for CK7, CD10 and RCC and positive for both WT1 (nuclear, intense) and vimentin (cytoplasmic, intense, and diffuse). Molecular analysis revealed the BRAF gene mutation V600E in three cases and wild-type BRAF in the fourth. CONCLUSIONS: BRAF molecular mutation analysis may aid diagnosis in cases with atypical histological features, especially in small incisional biopsies when reassessment of surgical treatment may be considered.

Clinical and pathological features of Merkel cell carcinoma: A 4-year follow-up observational retrospective study in Spain.

BACKGROUND: Merkel cell carcinoma (MCC) is a malignant skin cancer with a 5-year survival rate of approximately 50%. Knowledge of MCC has increased in recent years mostly due to improved diagnosis techniques. In Spain there is lack of information regarding the incidence and tumour characteristics, and the treatment approaches are not standardised. The objective of this study was to provide information of the clinical and epidemiological characteristics of MCC patients in Spain. METHODS: Retrospective, observational study involving 192 patients from 25 Spanish hospitals. Evaluated variables included overall survival and incidence rate of Merkel cell polyomavirus, in patients diagnosed from 2012 to 2016. RESULTS: The Spanish incidence rate was estimated 0.32/100,000 inhabitants/year, with variations according to geographical regions, being slightly higher in areas with greater sunlight exposure. In total, 61.5% of tumours showed expansive growth (progressive growth of the tumour), 78.6% showed localisation in UV-exposed skin. 97.4% of patients were diagnosed by excisional biopsy. Surgery was the first line treatment in 96.6% of patients, radiotherapy in 24.6%, and chemotherapy in 6.3%. These treatments were not mutually exclusive. Median overall survival was 38.3 months (78.4% at 12 months and 60% at 24 months). MCPyV was present in 33.8% of patients. CONCLUSION: The incidence of MCC in Spain is one of the highest in Europe, with a slight predominance in men. The sample has shown that a biopsy is available for diagnosis in most cases. Moreover, the treatment is surgical when the tumour is localized and is associated with lymphadenectomy, and/or it is radiotherapy if widespread.

Comprehensive NGS Panel Validation for the Identification of Actionable Alterations in Adult Solid Tumors.

The increasing identification of driver oncogenic alterations and progress of targeted therapies addresses the need of comprehensive alternatives to standard molecular methods. The translation into clinical practice of next-generation sequencing (NGS) panels is actually challenged by the compliance of high quality standards for clinical accreditation. Herein, we present the analytical and clinical feasibility study of a hybridization capture-based NGS panel (Action OncoKitDx) for the analysis of somatic mutations, copy number variants (CNVs), fusions, pharmacogenetic SNPs and Microsatellite Instability (MSI) determination in formalin-fixed paraffin-embedded (FFPE) tumor samples. A total of 64 samples were submitted to extensive analytical validation for the identification of previously known variants. An additional set of 166 tumor and patient-matched normal samples were sequenced to assess the clinical utility of the assay across different tumor types. The panel demonstrated good specificity, sensitivity, reproducibility, and repeatability for the identification of all biomarkers analyzed and the 5% limit of detection set was validated. Among the clinical cohorts, the assay revealed pathogenic genomic alterations in 97% of patient cases, and in 82.7%, at least one clinically relevant variant was detected. The validation of accuracy and robustness of this assay supports the Action OncoKitDx's utility in adult solid tumors.

[Protocol for the histologic diagnosis of cutaneous melanoma: consensus statement of the Spanish Society of Pathology and the Spanish Academy of Dermatology and Venereology (AEDV) for the National Cutaneous Melanoma Registry]. / Protocolo de diagnóstico histológico para muestras de pacientes con melanoma cutáneo. Documento de consenso de la SEAP y la AEDV para el Registro Nacional de Melanoma.

This article describes a proposed protocol for the histologic diagnosis of cutaneous melanoma developed for the National Cutaneous Melanoma Registry managed by the Spanish Academy of Dermatology and Venereology (AEDV). Following a review of the literature, 36 variables relating to primary tumors, sentinel lymph nodes, and lymph node dissection were evaluated using the modified Delphi method by a panel of 8 specialists (including 7 pathologists). Consensus was reached on the 30 variables that should be included in all pathology reports for cutaneous melanoma and submitted to the Melanoma Registry. This list can also serve as a model to guide routine reporting in pathology departments.

Mitotic count: A need for standardization.

PURPOSE: The mitotic count (MC), number of mitosis per unit area, is a very important parameter frequently used for classification and grading of some tumors. Traditionally, the MC has been expressed in terms of number of mitoses per high power field. The size of the field of view can vary greatly among different microscopes. In order to avoid under or overestimation of mitotic count, a conversion needs to be made. METHODS: A simple formula based on a simple rule of three has been devised to standardize the mitotic count to the reference area by multiplying the number of mitotic figures by a correction factor which has been calculated for the most frequently used microscopes and various common tumors. RESULTS AND CONCLUSIONS: We propose this simple method, which involves only a single multiplication, to standardize the mitotic count to the reference area.

Thyroid Metastasis From Cutaneous Melanoma on an 18F-FDG PET/CT Study.

The thyroid gland is an uncommon location for metastasis. We report a 59-year-old woman with a history of cutaneous malignant melanoma. A unique hypermetabolic mass on the left thyroid lobe was identified by control F-FDG PET/CT scan, leading to dysphagia and stridor clinic. Total thyroidectomy and lymphadenectomy were performed with histopathological results concordant with metastasis from melanoma. Despite its rarity, finding focal thyroid lesions in patients with an oncological history should alert us, recommending that its metastatic etiology be ruled out.

Frequency and Clinicopathological Profile Associated with Braf Mutations in Patients with Advanced Melanoma in Spain.

Real-world data on BRAF mutation frequency in advanced melanoma are lacking in Spain. Moreover, data available on clinicopathological profile of patients with advanced BRAF-mutant melanoma are currently limited. This study aimed to assess the frequency of BRAF V600 mutations in Spanish patients with advanced or metastatic melanoma and to identify clinical and histopathological features associated with BRAF-mutated tumors. A multicenter, cross-sectional epidemiological study was conducted in 33 Spanish hospitals in adult patients with stage IIIc/IV melanoma. A total of 264 patients were included. The median age was 68 years and 57% were male. Melanoma mainly involved skin with intermittent (40.4%) and low or no sun exposure (43.5%). Most patients (85.6%) had stage IV disease (M1a: 19.3%; M1b: 13.3%; M1c: 22.7%). Serum lactate dehydrogenase levels were elevated in 20% of patients. Superficial spreading melanoma was the most frequent histological type (29.9%). Samples were predominantly obtained from metastases (62.7%), mostly from skin and soft tissues (80%). BRAF mutation analysis was primarily performed using the Cobas 4800 BRAF V600 Mutation Test (92.8%) on formalin-fixed, paraffin-embedded tissue (95.8%). BRAF mutations were detected in 41.3% of samples. Multivariate analysis identified age (odd ratio [OR] 0.975) and stage IV M1a (OR 2.716) as independent factors associated with BRAF mutation. The frequency of BRAF mutations in tumor samples from patients with advanced or metastatic melanoma in Spain was 41.3%. BRAF mutations seem to be more frequent in younger patients and stage M1a patients. This study provides the basis for further investigation regarding BRAF-mutated advanced melanoma in larger cohorts.

Collagen Anomalies as Clues for Diagnosis: Part 1.

BACKGROUND: Collagen is the most abundant protein in the body and the main structural component of the skin. OBJECTIVE: To provide a review of the histopathology of collagen alterations and to propose a classification with the most important types of collagen anomalies in dermatopathology. The authors describe some of the main morphological clues of collagen anomalies for specific diagnosis of some cutaneous inflammatory and neoplastic conditions. METHODS: The authors review histopathologic collagen anomalies, concerning both morphology and disposition in some inflammatory and neoplastic cutaneous conditions, and they review previous terminology and proposed a classification of the most important types of collagen anomalies that can be seen in dermatopathological practice. RESULTS: Collagen anomalies in skin can be classified into lamellar fibrosis, sclerosis, and "balls" and "rings" of collagen. Lamellar fibrosis presents as long and thin collagen bundles forming a delicate network, which can be disposed in a parallel pattern, onion-bulb-like pattern, and storiform pattern. Sclerosis is characterized by large, thick, and eosinophilic bundles of collagen, which may present as a homogenous-diffuse pattern or as individual thick bundles of collagen with few or abundant number of fibroblasts between them. Finally, the authors propose the terms "balls" and "rings" of collagen. The term "balls" of collagen stands for thick, homogenous, eosinophilic, globular collagen bundles, with no distinguishable individual composing fibers, which include the floating sign and the free-floating sign. The term "rings" of collagen is characterized by sclerotic collagen arranged in a homogenous rimming pattern around vessels without independent fibers in its composition. CONCLUSIONS: Collagen anomalies may be important clues to establish specific clues for specific diagnoses in dermatopathology.