Comprehensive Molecular Characterization of a Large Series of Calcified Chondroid Mesenchymal Neoplasms Widening Their Morphologic Spectrum.

Recently, FN1 fusions to receptor tyrosine kinase genes have been identified in soft tissue tumors with calcified chondroid matrix named calcifying chondroid mesenchymal neoplasms (CCMNs). We collected 33 cases of CCMN from the French network for soft tissue and bone tumors. We performed whole-exome RNA sequencing, expression analysis, and genome-wide DNA methylation profiling in 33, 30, and 20 cases of CCMN compared with a control group of tumors, including noncalcified tenosynovial giant cell tumor (TGCT).

Angioleiomyoma: An Update with a 142-Case Series.

Angioleiomyomas are uncommon, noncancerous, smooth muscle tumors that primarily arise from blood vessels. Previous studies have yielded limited data due to the lack of interdisciplinary approaches or restricted patient pools. This study aims to provide a comprehensive analysis of angioleiomyomas, including the demographic, clinical, radiological, and histopathological features, with a large number of patients.

Enhanced accuracy and reduced delay in diagnosing bone tumors within an expert sarcoma network: A nationwide study.

Introduction: Primary bone tumors encompass a range of rare and diverse lesions. Pathological diagnosis poses significant challenges, with histological discrepancies extensively studied in soft tissue sarcomas but lacking specific investigation in bone lesions. This study aimed to determine the rate of major diagnostic discrepancies in primary bone tumors, assessing whether initial histological analysis within an expert referral center network reduces this rate and final diagnostic delay.

Deep-seated dermatophytosis caused by Trichophyton rubrum in patient with Becker muscular dystrophy.

Trichophyton rubrum is a common fungal pathogen that usually causes superficial infection limited to epidermis only, so called dermatophytosis. However in immunocompromised patients, dermatophytosis can be exceptionally more invasive with extensive lesions involving deep tissues and generating sometimes systemic course. We report the case of a 43-year-old heart transplanted man, who presented with multiple deep-seated nodules and papules in the inguinal areas and in the buttocks.

Chordoma concurrent with benign notochordal cell tumor of the mobile spine. Should the chordoma part be biopsied? - A stepwise approach for management.

Some evidence suggests that benign notochordal tumors (BNCTs) could be a potential precursor of chordoma. We present an educational rare case of lumbar vertebral BNCTs concomitant with a destructive lesion not reachable on biopsy but thought to be chordoma. We present a stepwise approach for management of these difficult entities based on radiological features.

Intraosseous Hibernoma: A Rare Entity in Orthopedics With Peculiar Radiological Features.

Intraosseous hibernoma is a rare benign bone tumor derived from brown fat. It is typically found in the axial skeleton and is more commonly observed in women. It can manifest as a painful lesion or may be incidentally discovered.

Giant Cell Tumors With HMGA2::NCOR2 Fusion : Clinicopathologic, Molecular, and Epigenetic Study of a Distinct Entity.

Giant cell tumors (GCTs) with high mobility group AT-Hook 2 ( HMGA2 )::nuclear receptor corepressor 2 ( NCOR2 ) fusion are rare mesenchymal tumors of controversial nosology, which have been anecdotally reported to respond to CSFR1 inhibitors. Here, we performed a comprehensive study of 6 GCTs with HMGA2::NCOR2 fusion and explored their relationship with other giant cell-rich neoplasms. Tumors occurred in 4 females and 2 males ranging in age from 17 to 32 years old (median 24).

Distinct Cellular Origins and Differentiation Process Account for Distinct Oncogenic and Clinical Behaviors of Leiomyosarcomas.

In leiomyosarcoma (LMS), a very aggressive disease, a relatively transcriptionally uniform subgroup of well-differentiated tumors has been described and is associated with poor survival. The question raised how differentiation and tumor progression, two apparently antagonist processes, coexist and allow tumor malignancy. We first identified the most transcriptionally homogeneous LMS subgroup in three independent cohorts, which we named 'hLMS'.

Standardized and axially vascularized calcium phosphate-based implants for segmental mandibular defects: A promising proof of concept.

The reconstruction of massive segmental mandibular bone defects (SMDs) remains challenging even today; the current gold standard in human clinics being vascularized bone transplantation (VBT). As alternative to this onerous approach, bone tissue engineering strategies have been widely investigated. However, they displayed limited clinical success, particularly in failing to address the essential problem of quick vascularization of the implant.

Histopathogenesis of bone- and soft-tissue tumor spectrum with USP6 gene rearrangement: multiple partners involved in the tissue repair process.

Primary aneurysmal bone cyst, nodular fasciitis, myositis ossificans and related lesions as well as fibroma of tendon sheath are benign tumors that share common histological features and a chromosomal rearrangement involving the ubiquitin-specific peptidase 6 (USP6) gene. The tumorigenesis of this tumor spectrum has become complex with the identification of an increasing number of new partners involved in USP6 rearrangements. Because traumatic involvement has long been mentioned in the histogenesis of most lesions in the USP6 spectrum and they morphologically resemble granulation tissue or callus, we attempted to shed light on the function and role USP6 partners play in tissue remodelling and the repair process and, to a lesser extent, bone metabolism.

A calpain-6/YAP axis in sarcoma stem cells that drives the outgrowth of tumors and metastases.

Sarcomas include cancer stem cells, but how these cells contribute to local and metastatic relapse is largely unknown. We previously showed the pro-tumor functions of calpain-6 in sarcoma stem cells. Here, we use an osteosarcoma cell model, osteosarcoma tissues and transcriptomic data from human tumors to study gene patterns associated with calpain-6 expression or suppression.

Recurrent YAP1::MAML2 fusions in "nodular necrotizing" variants of myxoinflammatory fibroblastic sarcoma: a comprehensive study of 7 cases.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare soft tissue tumor with a predilection for the distal extremities and a tendency for local recurrence. Morphologically, MIFS consists of spindle and bizarre epithelioid cells resembling virocytes embedded in a fibrous to myxoid stroma with an abundant inflammatory infiltrate. Importantly, the molecular landscape of MIFS is wide and includes: VGLL3 amplification, BRAF fusion/amplification and OGA/TGFBR3 rearrangements.

[Giant-cell tumor of bone in 2022].

Giant cell tumors of bone (GCTs) are rare mesenchymal tumors classified as intermediate in the WHO 2020 classification, i.e. neither completely benign nor definitely malignant, due to recurrence (frequent) and pulmonary metastases (rare).

Clinicopathologic and Molecular Study of Hybrid Nerve Sheath Tumors Reveals Their Common Association With Fusions Involving VGLL3.

A subset of benign peripheral nerve sheath tumors are "hybrid" combining several lines of differentiation, most often schwannian and perineurial features. The pathogenesis of these tumors was poorly described until the recent discovery of recurrent VGLL3 rearrangements in hybrid schwannoma/perineuriomas, supporting the hypothesis that this entity represents a distinct subgroup of tumors and not only a morphologic variation of other peripheral nerve sheath tumors. Following this finding, we investigated 10 cases of hybrid peripheral nerve sheath tumors with immunohistochemistry, RNA sequencing, and array comparative genomic hybridization.

Sphingosine Kinase-1 Is Overexpressed and Correlates with Hypoxia in Osteosarcoma: Relationship with Clinicopathological Parameters.

The Sphingosine kinase-1/Sphingosine 1-Phosphate (SphK1/S1P) signaling pathway is overexpressed in various cancers, and is instrumental for the adaptation to hypoxia in a number of solid tumor models, but no data are available in osteosarcoma. Here we report that SphK1 and the S1P receptor are involved in HIF-1α accumulation in hypoxic osteosarcoma cells. FTY720 (Fingolimod), which targets SphK1 and S1P prevented HIF-1α accumulation, and also inhibited cell proliferation in both normoxia and hypoxia unlike conventional chemotherapy.

Unexpected severe hepatic and skin toxicities during high dose methotrexate course for osteosarcoma.

Introduction: high dose methotrexate (HD-MTX) regimen is used in osteosarcoma, leukemia and lymphoma treatment. Osteosarcoma is mostly diagnosed in children and adolescents. Most frequent methotrexate toxicities are mucositis, myelosuppression, renal failure, hepatitis and necrotizing encephalopathy.

[From an optimal management of bone tissue samples to a quality patients' care in 2022 : A new paradigm].

Bone tissue can be involved by primitive or metastatic tumors and requires a specific processing both at the department of pathology and during multidisciplinary meetings. The development of fine-needle percutaneous biopsies and of molecular techniques in bone tumor pathology requires a specific management. Moreover, decalcification of samples is crucial but can be deleterious if not controlled or not appropriate.

[Notochordal tumors: From notochord to chordoma].

The group of notochordal tumors consists of the benign notochordal cell tumor and the conventional, dedifferentiated and poorly differentiated chordomas in the fifth edition of the WHO classification of bone and soft tissue tumors. This update covers recent advances in the knowledge of the histogenesis and biology of these tumors and their implications in terms of diagnosis, prognosis assessment and therapeutic management.

[Bilateral giant cell central granuloma of the jaws in a Noonan syndrome: About one case with emphasizing on bone giant cell lesions of the jaws].

We report the case of a 10-year-old child with bilateral mandibular localization of a central giant cell granuloma occurring in the setting of Noonan syndrome. The histological appearance was classic with two intermigled components, one fibrous with non-atypical mononuclear cells, the other consisting of numerous osteoclast-like giant cells. This aspect is similar to that observed in the brown tumor as well as that of cherubism, which can also give multiple bone lesions.