Chromosomal imbalances in some benign orbital tumours

Orbital Vascular Anomalies: A Nomenclatorial, Etiological, and Nosologic Conundrum

PURPOSE

Vascular anomalies are a heterogeneous group of disorders that frequently present in the periorbital region. They encompass 2 broad entities: vascular tumors, which possess a proliferative endothelium, and vascular malformations, which are basically localized defects of vascular morphogenesis. The primary goal of this review was to address inaccurate or controversial terminology in the oculoplastic literature concerning orbital and periorbital vascular anomalies and to categorize these lesions in an abridged and simplified hierarchical list that adheres as much as possible to the most recent (2018) iteration for the classification of vascular lesions proposed by the International Society for the Study of Vascular Anomalies (ISSVA). The secondary goal of this review was to review and update information regarding the genetic underpinnings of vascular anomalies and the downstream signaling pathways that are subsequently affected as a result of these genetic errors.

METHODS

A literature review was conducted in PubMed, MEDLINE, PubMed Central, National Center for Biotechnology Information Bookshelf, and Embase for several related keywords including "vascular anomalies, vascular malformations, vascular tumors, and cavernous venous malformation," both with and without adding the keywords "eyelid," "orbital," and "periorbital." In addition, a detailed search was conducted for controversial or obsolete keywords like "cavernous hemangioma," "lymphangioma," and "varices," again in their systemic and orbital/periorbital context.

RESULTS

Crucial issues in the 2018 ISSVA classification regarding the proper categorization of orbital vascular anomalies, particularly venous lesions, were critically evaluated and revised, and a regional, simplified, and abridged modification of the ISSVA 2018 classification was proposed.

CONCLUSIONS

Interdisciplinary and intradisciplinary dialogue concerning orbital vascular anomalies is seriously compromised due to the lack of a unanimous agreement on terminology and the absence of a unified classification concept system. The authors recommend that oculoplastic surgeons adopt ISSVA terminology whenever technically possible and scientifically sound. However, they also propose modifying the ISSVA 2018 classification specifically to adapt to the peculiarities of vascular anomalies in the periorbital region. At present, the simplified classification proposed here is a preliminary first step towards managing patients with orbital vascular anomalies with greater diagnostic and therapeutic precision, until such time in the future when the entire genetic makeup of orbital vascular anomalies is more completely elucidated. Optimistically, this could pave the way for a more robust classification and the ultimate therapeutic cure.

Recent Advances in the Genetic of MALT Lymphomas

Simple Summary

Mucosa-associated lymphoid tissue (MALT) lymphoma is the most common subtype of marginal zone lymphomas. These B-cell neoplasms may arise from many organs and usually have an indolent behavior. Recurrent chromosomal translocations and cytogenetic alterations are well characterized, some of them being associated to specific sites. Through next-generation sequencing technologies, the mutational landscape of MALT lymphomas has been explored and available data to date show that there are considerable variations in the incidence and spectrum of mutations among MALT lymphoma of different sites. Interestingly, most of these mutations affect several common pathways and some of them are potentially targetable. Gene expression profile and epigenetic studies have also added new information, potentially useful for diagnosis and treatment. This article provides a comprehensive review of the genetic landscape in MALT lymphomas.

Abstract

Mucosa-associated lymphoid tissue (MALT) lymphomas are a diverse group of lymphoid neoplasms with B-cell origin, occurring in adult patients and usually having an indolent clinical behavior. These lymphomas may arise in different anatomic locations, sharing many clinicopathological characteristics, but also having substantial variances in the aetiology and genetic alterations. Chromosomal translocations are recurrent in MALT lymphomas with different prevalence among different sites, being the 4 most common: t(11;18)(q21;q21), t(1;14)(p22;q32), t(14;18)(q32;q21), and t(3;14)(p14.1;q32). Several chromosomal numerical abnormalities have also been described, but probably represent secondary genetic events. The mutational landscape of MALT lymphomas is wide, and the most frequent mutations are: TNFAIP3, CREBBP, KMT2C, TET2, SPEN, KMT2D, LRP1B, PRDM1, EP300, TNFRSF14, NOTCH1/NOTCH2, and B2M, but many other genes may be involved. Similar to chromosomal translocations, certain mutations are enriched in specific lymphoma types. In the same line, variation in immunoglobulin gene usage is recognized among MALT lymphoma of different anatomic locations. In the last decade, several studies have analyzed the role of microRNA, transcriptomics and epigenetic alterations, further improving our knowledge about the pathogenic mechanisms in MALT lymphoma development. All these advances open the possibility of targeted directed treatment and push forward the concept of precision medicine in MALT lymphomas.

[Diagnostics of benign and malignant tumors of the orbit]

BACKGROUND

Orbital space-occupying lesions can have a significant impact on the quality of life. Depending on the dignity and etiology of the mass, they can even represent a life-threatening process, which must be timely treated in an interdisciplinary cooperation.

OBJECTIVE

To achieve a comprehensive overview about the diagnostics and frequency of malignant and benign masses of the orbit.

MATERIAL AND METHODS

A literature search was carried out in PubMed and Google scholar.

RESULTS AND DISCUSSION

Clinically, orbital lesions can show symptoms, such as exophthalmos with an increase in the vertical lid fissure, visual impairment and motility dysfunction with diplopia. Depending on the extent, an exposure keratopathy can occur due to failure to close the eyelids. For the diagnostics several tests should be carried out. Following a thorough anamnesis and clinical examination, these should include a blood sample to test for various parameters, an ultrasound examination with subsequent computed tomography (CT) in cases of bone involvement or thin slice magnetic resonance imaging (MRI) of the orbit for assessment of soft tissues. In adults an endocrine orbitopathy is the most frequent cause of an inflammatory orbital process, where lymphomas are the most frequent entity among malignant tumors and vascular space-occupying lesions are the most frequent benign tumors. In children the most frequent benign masses are dermoid cysts and rhabdomyosarcoma is the most frequent primary malignant orbital tumor. The multimodal interdisciplinary treatment can include surgical excision and adjuvant radiotherapy or chemotherapy, depending on the entity.

DeepACEv2: Automated Chromosome Enumeration in Metaphase Cell Images Using Deep Convolutional Neural Networks

Chromosome enumeration is an essential but tedious procedure in karyotyping analysis. To automate the enumeration process, we develop a chromosome enumeration framework, DeepACEv2, based on the region based object detection scheme. The framework is developed following three steps. Firstly, we take the classical ResNet-101 as the backbone and attach the Feature Pyramid Network (FPN) to the backbone. The FPN takes full advantage of the multiple level features, and we only output the level of feature map that most of the chromosomes are assigned to. Secondly, we enhance the region proposal network's ability by adding a newly proposed Hard Negative Anchors Sampling to extract unapparent but essential information about highly confusing partial chromosomes. Next, to alleviate serious occlusion problems, besides the traditional detection branch, we novelly introduce an isolated Template Module branch to extract unique embeddings of each proposal by utilizing the chromosome's geometric information. The embeddings are further incorporated into the No Maximum Suppression (NMS) procedure to improve the detection of overlapping chromosomes. Finally, we design a Truncated Normalized Repulsion Loss and add it to the loss function to avoid inaccurate localization caused by occlusion. In the newly collected 1375 metaphase images that came from a clinical laboratory, a series of ablation studies validate the effectiveness of each proposed module. Combining them, the proposed DeepACEv2 outperforms all the previous methods, yielding the Whole Correct Ratio(WCR)(%) with respect to images as 71.39, and the Average Error Ratio(AER)(%) with respect to chromosomes as about 1.17.

Varifocal-Net: A Chromosome Classification Approach Using Deep Convolutional Networks

Chromosome classification is critical for karyotyping in abnormality diagnosis. To expedite the diagnosis, we present a novel method named Varifocal-Net for simultaneous classification of chromosome's type and polarity using deep convolutional networks. The approach consists of one global-scale network (G-Net) and one local-scale network (L-Net). It follows three stages. The first stage is to learn both global and local features. We extract global features and detect finer local regions via the G-Net. By proposing a varifocal mechanism, we zoom into local parts and extract local features via the L-Net. Residual learning and multi-task learning strategies are utilized to promote high-level feature extraction. The detection of discriminative local parts is fulfilled by a localization subnet of the G-Net, whose training process involves both supervised and weakly supervised learning. The second stage is to build two multi-layer perceptron classifiers that exploit features of both two scales to boost classification performance. The third stage is to introduce a dispatch strategy of assigning each chromosome to a type within each patient case, by utilizing the domain knowledge of karyotyping. The evaluation results from 1909 karyotyping cases showed that the proposed Varifocal-Net achieved the highest accuracy per patient case (%) of 99.2 for both type and polarity tasks. It outperformed state-of-the-art methods, demonstrating the effectiveness of our varifocal mechanism, multi-scale feature ensemble, and dispatch strategy. The proposed method has been applied to assist practical karyotype diagnosis.

Cavernous venous malformation (cavernous hemangioma) of the orbit: Current concepts and a review of the literature

The cavernous venous malformation of the orbit, previously called cavernous hemangioma, is the most common primary orbital lesion of adults. Cavernous venous malformation occurs more often in women and typically presents in the fourth and fifth decades of life. It is a benign vascular malformation characterized by a well-defined capsule and numerous large vascular channels. The most common sign of cavernous venous malformation is progressive axial proptosis from the preferential involvement of the intraconal orbital space. Optic nerve damage and other signs of orbital pathology may be present, with a variable degree of visual impairment. The combination of ultrasound, computed tomography, and magnetic resonance imaging leads to an accurate diagnosis in the vast majority of cases. Surgical and nonsurgical treatments are required in case of symptomatic lesions, with a characteristic multidisciplinary management influencing optimal outcome. Orbitotomy represents the traditional surgical approach. Recently, the endoscopic transnasal approach to the orbital cavity has gained interest, representing a feasible and safe, less-invasive surgical technique for the management of cavernous venous malformation.

Co-occurrence of a cerebral cavernous malformation and an orbital cavernous hemangioma in a patient with seizures and visual symptoms: Rare crossroads for vascular malformations

Background:

Cerebral cavernous malformations (CCMs) are angiographically occult vascular malformations of the central nervous system. As a result of hemorrhage and mass effect, patients may present with focal neurologic deficits, seizures, and other symptoms necessitating treatment. Once symptomatic, most often from hemorrhage, CCMs are treated with microsurgical resection. Orbital cavernous hemangiomas (OCHs) are similar but distinct vascular malformations that present within the orbital cavity. Even though CCMs and OCHs are both marked by dilated endothelial-lined vascular channels, they are infrequently seen in the same patient.

Case Description:

We provide a brief overview of the two related pathologies in the context of a patient presenting to our care with concomitant lesions, which were both resected in full without complication.

Conclusion:

This is the first known report that describes a case of concomitant CCM and OCH and explores the origins of two pathologies that are rarely encountered together in neurosurgical practice. Recognition of disparate symptomatologies is important for properly managing these patients.

Genetic testing in orbital tumors

OBJECTIVE

This review aims to discuss the clinical application of cytogenetic and molecular testing in the diagnosis and prognosis of orbital tumors and, in so doing, highlight the basis of these methods, their advantages, and limitations.

SUMMARY

Specific chromosomal aberrations are detected in many lymphoproliferative neoplasms, soft tissue tumors, and in a few benign tumors of the orbit. Detection of these characteristic chromosomal translocations is most helpful to refine the diagnosis and classification, especially when the tumor is poorly differentiated and shows overlapping morphological features with another tumor type. This review outlines orbital tumors with characteristic chromosomal translocations and the relative frequency of detecting the genetic mutation. Various genetic techniques are available for genetic testing, including karyotyping, fluorescence in situ hybridization (FISH), reverse transcriptase polymerase chain reaction (RT-PCR), and genomic polymerase chain reaction (PCR). As yet, the newer methods of array-comparative genomic hybridization (array-CGH) and expression profiling are most commonly used in research settings or in large specialist centers, and their general application to cancer diagnostics is limited by their cost. Therefore, this review focuses on the methodologies that should be available to most diagnostic units. It is true that "one size does not fit all" in this field and that a combination of molecular techniques may be needed to confirm results at the genomic and transcriptional levels.

Chromosomal imbalances are associated with increased proliferation and might contribute to bone destruction in cholesteatoma

OBJECTIVES

Our aim was to evaluate the copy number alterations of chromosomes 3, 7, 8, and 17 in middle ear cholesteatomas and define the association between the rate of cell proliferation and chromosome number changes.

METHODS

Tissues were obtained from 16 patients. Fluorescence in situ hybridization was performed on tumor imprint preparations. Cell proliferation was characterized with Ki-67 monoclonal antibody on cholesteatoma samples and on postauricular skins as control.

RESULTS

Different degrees of aneusomy were found for all chromosomes except for chromosome 3. Chromosome copy number alterations were associated with elevated proliferative rate and related also with the aggressiveness of the lesions.

CONCLUSIONS

Based on our results, we assume that aneusomy of chromosomes 7, 8, and 17 might play an important role during invasion of the adjacent bony structures of cholesteatoma, as well as associate with increased cell proliferation activity, which might lead to the aggressive behavior of the tissue.

Histological study of osteoid osteoma's blood supply

The osteoid osteoma is a painful lesion with a special predilection for the femur and tibia of young patients. Although the lesion has been described as richly innervated, its vascular supply has not been critically appraised to date in the pathology literature. To this end, we have undertaken a morphological study of 16 archival cases of osteoid osteoma, focusing primarily on the patterns of vascularization, utilizing traditional histological and immunohistochemical approaches. The study demonstrated that a prominent arterial and arteriolar blood supply was a constant finding within the various zones of soft tissues, skeletal muscle, and bone surrounding the nidus. It also showed that the caliber of the vessels underwent gradual attenuation throughout their centripetal course toward the nidus, where the vessels lost their muscularis as they merged into the capillary network of the nidus. Immunostaining with antibodies to neurofilament and S100 proteins revealed a pattern of innervation that was overall less exuberant than that described in some reports and that was virtually absent from the nidus. Taken together with data reported in the radiological literature, our findings lead us to wonder whether the osteoid osteoma may represent a response to the local stimulation of bony tissue by a primarily aberrant vasculature, a hypothesis that warrants further elucidation using state-of-the-art imaging approaches.

Chromosomal imbalances in a recurrent solitary fibrous tumor of the orbit

Using comparative genomic hybridization (CGH), array CGH, fluorescence in situ hybridization, and loss of heterozygosity analysis, we examined a recurrent solitary fibrous tumor of the orbit for chromosomal imbalances. In the primary tumor, loss of chromosomal material was observed at 9p, 9q, and 16q. In the first recurrent tumor, cells with these abnormalities were detected, but in some parts of the tumor, cells with losses at 13q (homozygous deletion at 13qter) and 20p were dominant. In the second recurrence, only cells with losses at 13q and 20p were seen. Although morphologically similar, the second recurrent tumor invaded the anterior cranial fossa and demonstrated considerably faster growth than the first recurrent tumor. Thus, the clone of tumor cells that dominated the second recurrent tumor was shown by cytogenetic analysis to be different from that present in the primary tumor, and was associated with a more aggressive nature of the tumor.