Search Results (18)

Background and Objectives: Spitz tumors represent a diagnostic challenge in dermatopathology due to their large spectrum of morphological characteristics and overlap with malignant lesions, especially in pathology departments where molecular pathology is not available. Even though most Spitz lesions are benign, the uncertainty around their biological behavior necessitates an integrated approach in daily practice. The objective of our study was to evaluate the epidemiological, macroscopic, and histopathological characteristics of Spitz lesions in accordance with WHO Classification of Skin Tumours. Materials and Methods: We performed a retrospective, descriptive, and hypothesis-generating study on Spitz tumors diagnosed between 2018 and 2024 in the Clinical Pathology Department of the Mures Clinical County Hospital, Romania. We included 10 cases and analyzed their macroscopic characteristics (localization, shape, dimension, and color), microscopic characteristics (cellular types, cytologic atypia, pagetoid migration, mitoses, and the type of lesion), and immunohistochemical profile. Results: The study population was composed of young patients with an average age of 20.2 years old, with a slight predominance of female gender. Most lesions were Spitz nevi, intradermic, or compound, with a fusiform, epithelioid, or rhomboid cell shape. Pagetoid migration and cytological atypia were seen in fewer cases. The Ki 67 proliferation index was under 5% in all cases. The main limitation of this study involved the low number of cases and the lack of molecular testing, which limited the molecular characterization of Spitz tumors. Complete excision was performed in all cases. Conclusions: In the absence of molecular testing, our study emphasizes the importance of clinical–morphological assessment using immunohistochemistry in establishing a correct diagnosis in Spitz lesions. Our results confirm that most of the Spitz lesions were benign and provide a basis for future research with a multidisciplinary approach, including molecular testing. Full article

Background: Spitz tumors (STs) are a diverse group of melanocytic lesions that range from benign to malignant. STs pose significant classification challenges due to overlapping histological and immunohistochemical (IHC) features among the STs with different malignant potential. This study aimed to assess the diagnostic value of a melanoma-specific next-generation sequencing (NGS) panel (MelArray) combined with IHC analysis to improve the assessment of diagnostically challenging ST cases. Methods: Patients with STs and available MelArray results were included in this retrospective analysis. Molecular analysis (genetic alterations, tumor mutational burden (TMB), and copy number variations (CNV)), clinical data (demographics and clinical course), and IHC data (scores for markers such as p16, Ki-67, HMB45, PRAME, and Melan A) were evaluated in conjunction and correlated with patient outcomes. Results: Atypical Spitz tumors (ASTs, n = 20) predominantly exhibited heterozygous deletions in melanoma-relevant genes, but these were not accompanied by the multiple damaging mutations commonly associated with melanoma. IHC scores were higher in ASTs compared to Spitz nevi (SN, n = 3), suggesting an intermediate biologic potential. SN exhibited minimal genetic alterations and low IHC scores, reflecting a benign profile. Genetic analysis of the Spitz melanoma (SM, n = 1) revealed a distinct molecular profile with damaging mutations affecting the key regulatory pathways involved in tumor progression, along with a high TMB, and an IHC score comparable to ASTs. During a median follow-up of 36 months (range: 6–48 months, n = 23), no recurrences, distant metastases, or tumor-related deaths were observed. Conclusions: The integration of NGS analysis with the MelArray panel, histology, and immunohistochemistry, enhances the diagnostic accuracy of challenging STs by identifying the genetic alterations linked to malignancy risk. This aids in the detection of high-risk lesions that need a more detailed work-up and more stringent follow-up, and those that will follow a benign course. Larger studies are needed to validate the clinical utility and broader applicability. Full article

Background and Aim: Ex vivo fluorescence confocal microscopy (FCM) systems are innovative optical imaging tools that create virtual high-resolution histological images without any standard tissue processing, either freezing or fixing in formalin and embedding in paraffin. These systems have opened an era that would revolutionize pathological examination by providing rapid, real-time assessments across various pathology subspecialties, potentially replacing conventional methods that are tissue- and time-consuming. This study aimed to present the first utilization of FCM in pediatric surgical oncology, focusing on assessing the benefits, particularly in facilitating rapid and accurate diagnosis. Methods: This preliminary study comprised five consecutive patients undergoing surgical biopsy for disease characterization and surgical strategy selection. After biopsy, tissue samples were prepared and analyzed using FCM without sectioning. A pathologist who evaluated macroscopic and microscopic images, once obtained remotely, could promptly indicate any interventions that require timeliness. Samples were then evaluated with conventional methods. Results: All five lesions were deemed suitable for evaluation. Preliminary diagnoses utilizing FCM included atypical Spitz nevus (1), Wilm’s tumor (1), lymph node reactive hyperplasia (1), malignant germ cell tumor of the testis (1), and Hodgkin’s lymphoma (1). Final histopathological analyses revealed atypical Spitz nevus (1), Wilm’s tumor (1), hyperplastic lymphadenopathy with a prevalent marginal pattern (1), mixed nonseminomatous malignant germinal neoplasm consisting of embryonal carcinoma (90%) and yolk sac tumor (10%), and Hodgkin’s lymphoma nodular sclerosis variant (1). In the case of diagnosis of atypical Spitz nevus, the widening of the resection margins was performed in the same surgery. In the case of testicular neoplasm, radical orchiectomy was performed. A high level of agreement between FCM evaluation and definitive histological examination was observed for all parameters evaluated. Conclusions: FCM represents a significant advancement in pathological imaging technology, offering potential benefits in enhancing traditional tissue processing methods. This preliminary report marks the first application of FCM in pediatric surgical oncology. Our findings underscore the promising role of FCM as an adjunctive tool in pediatric oncology, facilitating prompt diagnosis and treatment initiation. Full article

Background: Atypical Spitz tumor (AST) is an intermediate category among Spitz melanocytic neoplasms. Sentinel node biopsy (SNB) has been proposed in the clinical management of AST patients, but this approach remains the subject of debate. This systematic review aims to summarize the available evidence on SNB procedures in AST patients. Methods: A comprehensive search was conducted, including MEDLINE/Pubmed, EMBASE, and SCOPUS, through April 2023. Case series, cohort studies, and case–control studies of AST patients were eligible for inclusion. PRISMA guidelines were followed. Results: Twenty-two studies with a total of 756 AST patients were included. The pooled SNB prevalence was 54% (95% CI 32 to 75%), with substantial heterogeneity (I2 90%). The pooled SNB+ prevalence was 35% (95% CI 25 to 46%) with moderate heterogeneity (I2 39%). Lymphadenectomy was performed in 0–100% of SNB+ patients. Overall survival rates ranged from 93% to 100%, and disease-free survival ranged from 87% to 100% in AST patients. Overall and disease-free survival rates were 100% in SNB patients. Pooled survival estimates were not calculated due to the heterogeneous timing of the survival assessment and/or the small size of the subgroups. All studies clearly reported inclusion criteria and measured the condition in a standard way for all participants, but only 50% indicated valid methods for the identification of the condition. Conclusions: The oncologic behavior of AST is related to an almost always favorable outcome. SNB does not seem to be relevant as a staging or prognostic procedure, and its indication remains debatable and controversial. Full article

Spitz and Spitzoid lesions represent one of the most challenging melanocytic neoplasms in dermatopathology. Nosologic classification has been more recently improved by the discovery of novel molecular drivers, particularly translocations. In the current study, we aimed to use an unbiased approach to explore the gene expression profile of a group of melanocytic Spitz and Spitzoid melanocytic lesions ranging from benign lesions to melanoma, including intermediate lesions such as SPARK nevi and atypical Spitz tumors/melanocytomas. Using unsupervised analysis of gene expression data, we found some distinct hierarchical clusters of lesions, including groups characterized by ALK and NTRK translocations. Few non-ALK translocated tumors demonstrated increased ALK expression, confirmed by immunohistochemistry. Spitz tumors with overlapping features of dysplastic nevi, so-called SPARK nevi, appear to have a common gene expression profile by hierarchical clustering. Finally, weighted gene correlation network analysis identified gene modules variably regulated in subtypes of these cases. Thus, gene expression profiling of Spitz and Spitzoid lesions represents a viable instrument for the characterization of these lesions. Full article

The arena of melanocytic histopathology has experienced tremendous growth in the last decade. The advancement is attributed to incorporating various molecular tests in benign, intermediate, and malignant melanocytic tumors. Most molecular testing has been mainly applied in clinically advanced-stage melanoma to determine the molecular alteration to help guide therapy (e.g., BRAF inhibitors in BRAF mutated melanomas). However, with more availability and, to a certain degree, affordability of certain molecular tests, multiple studies have been conducted on benign/intermediate lesions in an attempt to understand further the driving molecular alterations allowing for the proliferation of certain melanocytic lineages. This review article discusses and illustrates examples of recently recognized entities with their corresponding genomic alterations in the Spitz lineage, blue nevi, deep penetrating melanocytomas, and pigmented epithelioid melanocytomas. Full article

In recent years, particular interest has developed in molecular biology applied to the field of dermatopathology, with a focus on nevi of the Spitz spectrum. From 2014 onwards, an increasing number of papers have been published to classify, stratify, and correctly frame molecular alterations, including kinase fusions. In this paper, we try to synthesize the knowledge gained in this area so far. In December 2023, we searched Medline and Scopus for case reports and case series, narrative and systematic reviews, meta-analyses, observational studies—either longitudinal or historical, case series, and case reports published in English in the last 15 years using the keywords spitzoid neoplasms, kinase fusions, ALK, ROS1, NTRK (1-2-3), MET, RET, MAP3K8, and RAF1. ALK-rearranged Spitz tumors and ROS-1-rearranged tumors are among the most studied and characterized entities in the literature, in an attempt (although not always successful) to correlate histopathological features with the probable molecular driver alteration. NTRK-, RET-, and MET-rearranged Spitz tumors present another studied and characterized entity, with several rearrangements described but as of yet incomplete information about their prognostic significance. Furthermore, although rarer, rearrangements of serine–threonine kinases such as BRAF, RAF1, and MAP3K8 have also been described, but more cases with more detailed information about possible histopathological alterations, mechanisms of etiopathogenesis, and also prognosis are needed. The knowledge of molecular drivers is of great interest in the field of melanocytic diagnostics, and it is important to consider that in addition to immunohistochemistry, molecular techniques such as FISH, PCR, and/or NGS are essential to confirm and classify the different patterns of mutation. Future studies with large case series and molecular sequencing techniques are needed to allow for a more complete and comprehensive understanding of the role of fusion kinases in the spitzoid tumor family. Full article

Over the last 75 years, our understanding of Spitz lesions has undergone substantial evolution. Initially considered a specific type of melanoma, the perception has shifted towards recognizing Spitz lesions as a spectrum comprising Spitz nevi, Spitz melanocytomas, and Spitz melanomas. Spitz lesions are known for posing a significant diagnostic challenge regarding the distinction between benign neoplasms displaying atypical traits and melanomas. A comprehensive understanding of their molecular basis and genomic aberrations has significantly improved precision in classifying and diagnosing these challenging lesions. The primary aim of this review is to encapsulate the current understanding of the molecular pathogenesis and distinct clinicopathologic characteristics defining this intriguing set of tumors. Full article

Current diagnostic algorithms are insufficient for the optimal clinical and therapeutic management of cutaneous spitzoid tumors, particularly atypical spitzoid tumors (AST). Therefore, it is crucial to identify new markers that allow for reliable and reproducible diagnostic assessment and can also be used as a predictive tool to anticipate the individual malignant potential of each patient, leading to tailored individual therapy. Using Reduced Representation Bisulfite Sequencing (RRBS), we studied genome–wide methylation profiles of a series of Spitz nevi (SN), spitzoid melanoma (SM), and AST. We established a diagnostic algorithm based on the methylation status of seven cg sites located in TETK4P2 (Tektin 4 Pseudogene 2), MYO1D (Myosin ID), and PMF1-BGLAP (PMF1-BGLAP Readthrough), which allows the distinction between SN and SM but is also capable of subclassifying AST according to their similarity to the methylation levels of Spitz nevi or spitzoid melanoma. Thus, our epigenetic algorithm can predict the risk level of AST and predict its potential clinical outcomes. Full article

After 25 years, “Ackerman’s conundrum”, namely, the distinction of benign from malignant Spitz neoplasms, remains challenging. Genomic studies have shown that most Spitz tumors harbor tyrosine and serine/threonine kinase fusions, including ALK, ROS1, NTRK1, NTRK2, NTRK3, BRAF and MAP3K8, or some mutations, such as HRAS and MAP3K8. These chromosomal abnormalities act as drivers, initiating the oncogenetic process and conferring basic bio-morphological features. Most Spitz tumors show no additional genomic alterations or few ones; others harbor a variable number of mutations, capable of conferring characteristics related to clinical behavior, including CDKN2A deletion and TERT-p mutation. Since the accumulation of mutations is gradual and progressive, tumors appear to form a bio-morphologic spectrum, in which they show a progressive increase of clinical risk and histological atypia. In this context, a binary classification Spitz nevus-melanoma appears as no longer adequate, not corresponding to the real genomic substrate of lesions. A ternary classification Spitz nevus-Spitz melanocytoma-Spitz melanoma is more adherent to the real neoplastic pathway, but some cases with intermediate ambiguous features remain difficult to diagnose. A prognostic stratification of Spitz tumors, based on the morphologic and genomic characteristics, as a complement to the diagnosis, may contribute to better treatment plans for patients. Full article

Atypical and malignant cutaneous tumors are understudied in the pediatric population, with limited data on long-term follow-up. This study examines pediatric (0–18 years) atypical melanocytic proliferations over a twenty-year period (January 2002–December2022) using the EPIC SlicerDicer at our institution. Over a twenty-year period, there were 55 cases of pediatric melanoma (53 patients). The median follow-up time was 8 years, 11 months. A proportion of 96% were treated with wide local excision (WLE), and 47% had a sentinel lymph node biopsy (SLNB) (35% positive rate). There were 101 atypical Spitz tumor cases (85% atypical Spitz tumors, 15% Spitz melanoma), with a median follow-up duration of 9 years. A proportion of 77% were treated with WLE (with one patient dying of metastatic disease). There were 10 cases of atypical melanocytic proliferations not otherwise specified, including 5 pigmented epithelioid melanocytomas (PEM), 4 deep-penetrating nevi, and 1 atypical cellular blue nevus. This study adds to the growing body of knowledge on pediatric atypical cutaneous melanocytic proliferations, aligning with many described characteristics such as disease location and overall survival rates, with distinct exceptions (higher melanoma positive SLNB rate, lower atypical Spitz tumor WLE rate, and a case of fatal metastatic atypical Spitz tumor). Full article

Over the past several decades, the study of Spitz neoplasms has flourished, with expanded conceptualization and refined terminology, providing a framework for the assessment and classification of Spitz nevi, atypical Spitz Tumors, and Spitz melanoma. Cancer genomics have generated concepts such as driver and passenger genes and clonal evolution, which can be applied to Spitz tumors. Herein, we provide a historical perspective, followed by a summary of current knowledge and clinical approaches for these challenging tumors. Full article

Spitz neoplasms are a heterogeneous group of melanocytic proliferations with a great variability in the histological characteristics and in the biological behavior. Thanks to recent discoveries, the morpho-molecular landscape of Spitz lineage is becoming clearer, with the identification of subtypes with recurrent features thus providing the basis for a more solid and precise tumor classification. Indeed, specific mutually exclusive driver molecular events, namely HRAS or MAP2K1 mutations, copy number gains of 11p, and fusions involving ALK, ROS, NTRK1, NTRK2, NTRK3, MET, RET, MAP3K8, and BRAF genes, correlate with distinctive histological features. The accumulation of further molecular aberrations, instead, promotes the increasing malignant transformation of Spitz neoplasms. Thus, the detection of a driver genetic alteration can be achieved using the appropriate diagnostic tests chosen according to the histological characteristics of the lesion. This allows the recognition of subtypes with aggressive behavior requiring further molecular investigations. This review provides an update on the morpho-molecular correlations in Spitz neoplasms. Full article

Atypical Spitz tumors (AST) deviate from stereotypical Spitz nevi for one or more atypical features and are now regarded as an intermediate category of melanocytic tumors with uncertain malignant potential. Activating NTRK1/NTRK3 fusions elicit oncogenic events in Spitz lesions and are targetable with kinase inhibitors. However, their prevalence among ASTs and the optimal approach for their detection is yet to be determined. A series of 180 ASTs were screened with pan-TRK immunohistochemistry and the presence of NTRK fusions was confirmed using FISH, two different RNA-based NGS panels for solid tumors, and a specific real time RT-PCR panel. Overall, 26 ASTs showed pan-TRK immunostaining. NTRK1 fusions were detected in 15 of these cases showing cytoplasmic immunoreaction, whereas NTRK3 was detected in one case showing nuclear immunoreaction. Molecular tests resulted all positive in only two ASTs (included the NTRK3 translocated), RNA-based NGS and real time RT-PCR were both positive in three cases, and FISH and real time RT-PCR in another two cases. In seven ASTs NTRK1 fusions were detected only by FISH and in two cases only by real time RT-PCR. The frequency of NTRK fusions in ASTs is 9%, with a clear prevalence of NTRK1 compared to NTRK3 alterations. Pan-TRK immunohistochemistry is an excellent screening test. Confirmation of NTRK fusions may require the use of different molecular techniques. Full article

The term “pseudomalignancy” covers a large, heterogenous group of diseases characterized by a benign cellular proliferation, hyperplasia, or infiltrate that resembles a true malignancy clinically or histologically. Here, we (i) provide a non-exhaustive review of several inflammatory skin diseases and benign skin proliferations that can mimic a malignant neoplasm in children, (ii) give pathologists some helpful clues to guide their diagnosis, and (iii) highlight pitfalls to be avoided. The observation of clinical–pathological correlations is often important in this situation and can sometimes be the only means (along with careful monitoring of the disease’s clinical course) of reaching a firm diagnosis. Full article