Inflammatory Myofibroblastic Tumour in Children: A Report of Two Cases and Review of Literature

ABSTRACT

Inflammatory myofibroblastic tumour in paediatric patients present with a diagnostic dilemma because of its clinical, radiological and histopathological features overlapping with other mesenchymal tumours common in this age. Because of its rarity, the exact features are still unclear. Here, we are reporting clinical, radiological and histopathological appearances of two such cases. In both cases, the exact diagnosis was confirmed only after immunohistochemistry. There is a need for further detailed study to exactly determine the natural course and prognosis of these tumours.

Cytologic features of mesenchymal, melanocytic and haematolymphoid tumours of the central nervous system and metastases

The current World Health Organization (WHO) classification of central nervous system (CNS) tumours includes several neoplasms that, while occurring in this location, are more frequently seen extracranially. These include mesenchymal, melanocytic and haematolymphoid neoplasms, as well as metastases. A few of these entities are exclusive of the CNS and have no extracranial counterpart. Despite their diverse histogenesis, these neoplasms share a peculiar predilection for involving meningeal structures. In fact, in the context of an intraoperative pathologic consultation of a meningeal tumour, virtually all these entities should be considered as potential diagnoses. Metastases in the CNS are very common. Most are carcinomas that cytologically resemble their site of origin. Loss of differentiation with cell dissociation and anaplasia and presence of accompanying fibrillary brain parenchyma can be a source of diagnostic problems. In this review, we intend to show the most relevant cytologic features of these tumours, and it is especially aimed at their analysis during intraoperative studies.

Vulvar angiomyofibroblastoma is molecularly defined by recurrent MTG1-CYP2E1 fusions

Angiomyofibroblastoma (AMF), a rare benign vulvovaginal mesenchymal tumour, poses a diagnostic challenge due to histologic and immunohistochemical overlap with other vulvar mesenchymal tumours. Recently, MTG1-CYP2E1 fusion transcripts were reported in 5/5 AMFs; no other genetic alterations have been described to date. Herein, we sought to investigate the frequency of the MTG1-CYP2E1 fusion and the presence of other potential genetic alterations in a cohort of AMFs (n = 7, patient age range: 28-49 years). Tumours demonstrated classic morphologic features including alternating hypo/hypercellular areas, capillary channels surrounded by epithelioid/spindled tumour cells, and variable amounts of mature adipose tissue. reverse transcription-polymerase chain reaction (RT-PCR) for MTG1-CYP2E1 fusion, performed in all seven cases, showed the fusion transcript in five of six cases (one case with technical failure). Two tumours, including the one lacking the fusion, were subjected to targeted next-generation sequencing (104 genes) and a sarcoma fusion assay (28 genes); the fusion negative AMF also underwent RNA sequencing. No additional mutations, copy number alterations, or fusion genes were identified with the assays employed. We conclude that the majority of AMFs harbour recurrent MTG1-CYP2E1 fusion transcripts and identification of this fusion may aid in the diagnosis.

Mesenchymal tumours of the gastrointestinal tract

Mesenchymal tumours represent a heterogenous group of neoplasms encopassing benign, intermediate malignancy, and malignant entities. Sarcomas account for approximately 1% of human malignancies. In consideration of their rarity as well as of intrinsic complexity, diagnostic accuracy represents a major challenge. Traditionally, mesenchymal tumours are regarded as lesions the occurrence of which is mostly limited to somatic soft tissues. However, the occurrence of soft tissue tumours at visceral sites represent a well recognized event, and the GI-tract ranks among the most frequently involved visceral location. There exist entities such as gastrointestinal stromal tumours (GIST) and malignant gastointestinal neuroectodermal tumors that exhibit exquisite tropism for the GI-tract. This review will focus also on other relevant clinico-pathologic entities in which occurrence at visceral location is not at all negligible.

NTRK-rearranged mesenchymal tumours: diagnostic challenges, morphological patterns and proposed testing algorithm

Oncogenic fusions involving neurotrophic receptor tyrosine kinase (NTRK) genes are being increasingly identified in a range of mesenchymal tumours unrelated to infantile fibrosarcoma or cellular congenital mesoblastic nephroma, where the canonical ETV6-NTRK3 fusion was first described more than two decades ago. Recognition of these NTRK-rearranged tumours poses a diagnostic challenge to surgical pathologists due to their non-specific clinical and pathological features. However, their recognition is of heightened importance, particularly in locally advanced and metastatic sarcomas, due to the recent availability of selective and highly effective targeted therapy. Herein, we present an Australian multi-institutional series of six of these rare NTRK-rearranged mesenchymal neoplasms to share the local experience and diagnostic challenges as well as to highlight key morphological patterns and immunoprofiles that provide the most helpful clues in routine practice. We also propose a diagnostic algorithm for the detection of these fusions, drawing attention to the limitations of ancillary studies including immunohistochemistry against tropomyosin receptor kinase (TRK) protein, fluorescence in situ hybridisation (FISH) and next generation sequencing.

A multicenter study of oral sarcomas in Brazil

OBJECTIVES

The aim of this study was to investigate the prevalence of oral sarcomas from geographic regions of Brazil.

MATERIALS AND METHODS

A cross-sectional study was conducted on biopsies obtained from January 2007 to December 2016 at twelve Brazilian oral and maxillofacial pathology centres. Gender, age, evolution time, clinical aspects, tumour location, tumour size at diagnosis, radiographic aspects and histopathological diagnosis were evaluated. Data were analysed using descriptive statistical methods.

RESULTS

From 176,537, a total of 200 (0.11%) oral sarcomas were reported, and the most prevalent were osteosarcomas (74 cases; 37%) and Kaposi's sarcomas (52 cases; 26%). Males were more affected than females at a mean age of 32.2 years old (range of 3-87 years). The most common symptoms were swelling¸ localised pain and bleeding at a mean evolution time of 5.14 months (range <1-156 months). The lesions were mostly observed in the mandible (90 cases; 45%), with a mean tumour size of 3.4 cm (range of 0.3-15 cm). Radiographically, the lesions presented a radiolucent aspect showing cortical bone destruction and ill-defined limits.

CONCLUSIONS

Oral sarcomas are rare lesions with more than 50 described subtypes. Osteosarcomas and Kaposi's sarcomas were the main sarcomas of the oral cavity in Brazil.

Factors affecting the uterine sarcomas developement and possibilities of their clinical diagnosis

OBJECTIVE

The main goal of this article is to summarize the known factors underlying the tumorigenesis of sarcomas and to present the limitations of clinical diagnosis.

DESIGN

A review article.

SETTINGS

Division of Molecular Medicine, Biomedical Center, JLF UK Martin, Slovakia; Department of Gynaecology and Obstetrics JLF UK and UNM Martin, Slovakia; Division of Oncology, Biomedical Center in Martin, JLF UK, Martin, Slovakia.

METHODS

An analysis and summarisation of published studies about etiology, aberrant factors and limmitations of clinical diagnosis of uterne sarcomas.

RESULTS AND CONCLUSIONS

Uterine sarcomas are heterogenous, malignant tumour types of mesenchymal origin with a very low incidence. On the other hand, sarcomas are very aggressive tumours with a poor prognosis, and a very low chance of surviving in general. The most common types of sarcomas are leiomyosarcomas, followed in percentage occurrence by endometrial stromal sarcomas and adenosarcomas. This tumour pathogenesis remains still relatively unknown. There are recognized only several predisposition factor types, and the limitated molecular-genetic aberrations associated with their occurrence. Importantly, the potential perturbation of the malignant mass during the implementation of invasive methods can be considered as the most serious risk factor. In regards to the visualization methods application, there are still limited ways of distinguishing between malignant and benign forms, especially in the case of leiomyosarcomas.