Mutational analysis using Sanger and next generation sequencing in sporadic spindle cell hemangiomas: A study of 19 cases

Vascular tumors of intermediate malignancy: An update

The term "hemangioendothelioma" is used for endothelial neoplasms of intermediate malignancy and describes a group of rare neoplasms having biologic behavior falling in between that of the benign hemangiomas and fully malignant angiosarcomas. The hemangioendotheliomas fall into several specific, clinicopathologically and genetically distinct entities, specifically epithelioid hemangioendothelioma, kaposiform hemangioendothelioma, papillary intralymphatic angioendothelioma and retiform hemangioendothelioma (hobnailed hemangioendothelioma), pseudomyogenic hemangioendothelioma, composite hemangioendothelioma, and YAP1::TFE3-fused hemangioendothelioma. The clinical, morphologic, immunohistochemical, and genetic features, and the differential diagnosis of each of these rare entities are discussed in this review.

Successful sirolimus treatment of spindle cell haemangiomas in a paediatric patient with Maffucci syndrome

A case of Maffucci syndrome in a paediatric patient was treated satisfactorily with sirolimus, creating an opportunity for complete surgical excision of spindle cell haemangiomas.

Benign and low-grade superficial endothelial cell neoplasms in the molecular era

Vascular tumors are the most common mesenchymal neoplasms of the skin and subcutis, and they encompass a heterogeneous group with diverse clinical, histological, and molecular features, as well as biological behavior. Over the past two decades, molecular studies have enabled the identification of pathogenic recurrent genetic alterations that can be used as additional data points to support the correct classification of these lesions. The purpose of this review is to summarize the available data related to superficially located benign and low-grade vascular neoplasms and to highlight recent molecular advances with the role of surrogate immunohistochemistry to target pathogenic proteins as diagnostic biomarkers.

Molecular Diagnostics of Vascular Tumors of the Skin

In this article, the authors have reviewed all the recent news regarding how the discovery of some novel and recurrent molecular and genetic changes has modified the classification of some entities and have addressed to the description of new variants of vascular tumors. And even more important, the authors also reviewed on how these findings, in addition to gain insight into the tumoral biology, portend significant clinical consequences not only regarding to their diagnosis but also to their management and prognosis because some of these mutations are potential targets for treatment. The authors have also highlighted immunohistochemical markers can help us as a surrogate marker of those molecular alterations.

Fusion of the COL4A5 Gene With NR2F2-AS1 in a Hemangioma Carrying a t(X;15)(q22;q26) Chromosomal Translocation

BACKGROUND/AIM

Hemangiomas are benign neoplastic proliferations of blood vessels. Cytogenetic information on hemangiomas is limited to four tumors with abnormal karyotypes. We report here a solitary chromosomal translocation and its molecular consequence in a hemangioma.

MATERIALS AND METHODS

A cavernous hemangioma was extirpated from the foot of a 62 years old man and genetically studied with cytogenetic and molecular genetic methodologies.

RESULTS

G-Banding analysis of short-term cultured tumor cells yielded the karyotype 46,Y,t(X;15)(q22;q26)[4]/46,XY[12]. RNA sequencing detected fusion of the collagen type IV alpha 5 chain gene (COL4A5 on Xq22.3) with intronic sequences of nuclear receptor subfamily 2 group F member 2 antisense RNA 1 (NR2F2-AS1 on 15q26.2) resulting in a putative COL4A5 truncated protein. The fusion was verified by RT-PCR together with Sanger sequencing and FISH analyses.

CONCLUSION

The involvement of COL4A5 indicates that some hemangiomas have pathogenetic similarities with other benign tumors such as leiomyomas and subungual exostosis.

[Classification of vascular tumours and vascular malformations. Contribution of the ISSVA 2014/2018 classification]

The study of vascular anomalies, "angiomas", vascular tumours and vascular malformations is made difficult by the great variety and confusion of the names used in the literature for these diseases, some of which are rare. The great merit of the classification proposed by the International Society for the Study of Vascular Anomalies (ISSVA), adopted in 2014 and modified in 2018, is to propose a unambiguous nomenclature and to try to group these lesions in a logical way, contrasting with the lists of the usual "classifications". This classification is based on the distinction between proliferative lesions (tumours and reactive lesions) and those which are due to a congenital anomaly of vascular morphogenesis (vascular malformations). It incorporates recent data on the molecular causes of these diseases. The major groups of lesions recognised in this classification will be presented and some lesions of interest briefly discussed. This classification aims to be usable by all medical specialties and applicable to all tissues and organs, even if efforts are still needed to integrate organ-specific names in order to unify the nomenclature and eliminate confusion. Even if it does not solve all the problems in this complex field, the unification of the nomenclature is a major contribution of this classification and pathologists are strongly encouraged to refer to it in daily practice.

Soft Tissue Special Issue: Perivascular and Vascular Tumors of the Head and Neck

Perivascular and vascular neoplasms of the head and neck are a rare group of tumors comprising a spectrum of clinical/biologic and histological features. They are frequently diagnostically challenging, due to their morphologic and immunohistochemical overlap. In this review, we summarize the pathology of these neoplasms, discussing morphology, immunohistochemistry, associated genetic findings, and the differential diagnoses.

The Molecular Diagnostics of Vascular Neoplasms

In this review, we provide an update of the recently discovered, diagnostically significant genetic aberrations harbored by a subset of vascular neoplasms. From benign (epithelioid hemangioma, spindle cell hemangioma), to intermediate (pseudomyogenic hemangioendothelioma), to malignant (epithelioid hemangioendothelioma, angiosarcoma), each neoplasm features a mutation or gene fusion that facilitates its diagnosis by immunohistochemistry and/or molecular ancillary testing. The identification of these genetic anomalies not only assists with the objective classification and diagnosis of these neoplasms, but also serves to help recognize potential therapeutic targets.

Comprehensive molecular and clinicopathological analysis of vascular malformations: A study of 319 cases

Vascular malformations are part of overgrowth syndromes characterized by somatic mosaic mutations or rarely by germline mutations. Due to their similarities and diversity, clinicopathological classification can be challenging. A comprehensive targeted Next Generation Sequencing screen using Unique Molecular Identifiers with a technical sensitivity of 1% mutant alleles was performed for frequently mutated positions in ≥21 genes on 319 formalin‐fixed paraffin‐embedded samples. In 132 out of 319 cases pathogenic mosaic mutations were detected affecting genes previously linked to vascular malformations e.g. PIK3CA (n=80), TEK (TIE2) (n=11), AKT1 (n=1), GNAQ (n=7), GNA11 (n=4), IDH1 (n=3), KRAS (n=9), and NRAS (n=1). Six cases harbored a combination of mutations in PIK3CA and in GNA11 (n=2), GNAQ (n=2), or IDH1 (n=2). Aberrations in PTEN and RASA1 with a variant allele frequency approaching 50% suggestive of germline origin were identified in six out of 102 cases tested; four contained a potential second hit at a lower allele frequency. Ninety‐one of the total 142 pathogenic mutations were present at a variant allele frequency <10% illustrating the importance of sensitive molecular analysis. Clinicopathological characteristics showed a broad spectrum and overlap when correlated with molecular data. Sensitive screening of recurrently mutated genes in vascular malformations may help to confirm the diagnosis and reveals potential therapeutic options with a significant contribution of PIK3CA/mTOR and RAS‐MAPK pathway mutations. The co‐existence of two activating pathogenic mutations in parallel pathways illustrates potential treatment challenges and underlines the importance of multigene testing. Detected germline mutations have major clinical impact.