Vascular tumors of the mediastinum

Benign lesions of the mediastinum

Mediastinal tumours represent a heterogeneous group of entities derived from the manifold structures located in or adjacent to the mediastinum. Due to the occurrence of some of these tumours in characteristic mediastinal compartments, an anatomical subdivision of the mediastinum in the prevascular (anterior), visceral (middle), and paravertebral (posterior) is helpful for the differential diagnosis. Benign anterior mediastinal tumours linked to an enlargement of the thymic gland mainly consist of thymic cysts and several types of thymic hyperplasia: true thymic hyperplasia, rebound hyperplasia, lymphofollicular hyperplasia, and so-called thymic hyperplasia with lymphoepithelial sialadenitis (LESA)-like features. Mature teratomas, ectopic (para)thyroid tissue, and benign thymic tumours such as thymolipoma or thymofibrolipoma represent further typical tumours of the anterior mediastinum. Pericardial, bronchogenic, or oesophageal duplication cysts predominate in the middle mediastinum, whereas neurogenic tumours and myelolipomas are characteristic findings in the posterior compartment. Vascular tumours, lipomas, adenomatoid tumours, Castleman disease, or mediastinitis are further examples of less frequent tumours or tumorous lesions affecting the mediastinum. This review focuses on benign mediastinal lesions with an emphasis on benign tumours of the thymus. Besides histology, characteristic epidemiological and clinical aspects prerequisite for the correct diagnosis and patient management are discussed.

The Pleural Origin of Retiform Hemangioendothelioma: An Unusual Origin of a Rare Diagnosis

Introduction

Vascular malignancies are categorized into benign hemangiomas, malignant angiosarcomas, and tumors of intermediate malignancy. Retiform hemangioendothelioma (RH) is one of the rare diagnoses belonging to the class of intermediate malignancies that was initially diagnosed.

Case Presentation

In this case report, we have reported a rare case of RH, a locally aggressive, vascular tumor of malignant potential presenting at an unusual site. The most observed locations of this soft tissue tumor are skin and subcutaneous tissues of extremities; however, this case of RH was observed in an unusual site called pleura, which is a rare occurrence related to this tumor. The presence of cell surface markers like CD31 and ERG of vascular and endothelial origin and the presence of hobnail appearance of endothelial channels on the biopsy profile supported the vascular origin of the tumor; the clinical features and imaging studies further confirmed the diagnosis of RH.

Conclusion

In this case report, a rare case of RH with an unusual site of origin was highlighted. RH is a vascular neoplasm; commonly observed sites of this vascular tumor were skin and subcutaneous tissue of the extremities; however, in this case, the site was unusually different, which was the pleura of the left lung.

Neurogenic tumours of the posterior mediastinum and differential diagnosis considerations

The mediastinal compartment harbours vital organs and structures, including the heart, great vessels, major airways, and thymus. These structures are embedded in and associated with soft-tissue elements consisting of adipose and fibro-collagenous tissue in which soft-tissue tumours may develop. A detailed inventory of soft-tissue tumours that may be encountered in the mediastinum based on the WHO 2013 classification was published in 2015. In addition, several comprehensive reviews on mediastinal soft-tissue pathology are available, including reviews focusing specifically on a single tumour type. This review will focus on primary neurogenic and spindle cell tumours of the somatic soft tissue of the posterior mediastinum and provide a discussion of the pertinent differential diagnoses.

Mediastinal Epithelioid Angiosarcoma, New Insights into an Uncommon Diagnosis: A Case Report and Literature Review

Angiosarcoma is an uncommon malignant mesenchymal neoplasm, accounting for 1-2% of all sarcomas. More than half are cutaneous, with the remainder arising in the deep soft tissue, breast, bone or viscera, particularly the liver, spleen and heart. Mediastinal angiosarcomas are exceedingly uncommon. While epithelioid morphology is sometimes a minor component in conventional angiosarcoma, tumors with a predominance of epithelioid morphologic features are designated as epithelioid angiosarcoma (EAS). This is a report of a 58-year-old woman presenting with severe chest pain, accompanied by worsening dyspnea and dysphagia. Chest computed tomography (CT) revealed a large pericardial effusion and a bulky mediastinal mass. Biopsy revealed a malignant neoplasm with vascular differentiation consistent with high-grade EAS. By immunohistochemistry, epithelioid angiosarcomas express endothelial cell markers, such as CD31, CD34, ERG and FLI-1. A variable proportion express low molecular weight cytokeratin (CK), epithelial membrane antigen (EMA) and CD30. The use of molecular techniques has proven useful in the diagnosis of this rare neoplasm. Targeted next generation sequencing showed aberrations in multiple genes including NRAS, KRAS, MYC and TP53.

The Utility of Fine Needle Aspiration (FNA) Biopsy in the Diagnosis of Mediastinal Lesions

Fine needle aspiration is a minimally invasive, low-morbidity, and cost-efficient technique for the sampling of mediastinal lesions. Additionally, ancillary testing on FNA samples can be used for the refinement of diagnoses and for treatment-related purposes (flow cytometry, cytogenetics, immunohistochemistry, and molecular diagnostics). Mediastinal lesions, however, can show a variety of lineages and morphologic features, giving rise to diagnostic dilemmas. As a result, the differential diagnosis can vary widely and becomes especially challenging due to the smaller sample size on FNA and the variability in component sampling. For appropriate patient management and to determine the correct treatment strategies, accurate pathologic diagnoses are paramount. In this review, we present the cytomorphologic features together with the immunophenotypic findings of mediastinal lesions, with emphasis on the diagnostic challenges and pitfalls in FNA cytology samples, including smears and cell block sections.

The surgical treatment of locally advanced angiosarcoma of the anterior mediastinum. A clinical case

Tumors of the mediastinum is a collective term that includes neoplasms of various degrees of malignancy, different morphogenesis, originating from heterogeneous tissues and combined into one nosological form according to anatomical localization. Angiosarcoma is a rare malignant tumor originating from a vessel wall. In the general structure of sarcomas, its frequency is estimated at 1%. The tumor is characterized by an aggressive course, local recurrence, hematogenous metastasis, poor sensitivity to chemotherapy and radiotherapy. Surgery remains the main treatment for angiosarcomas. The article presents a clinical case. A 55-year-old patient has multiple primary malignant neoplasms: cancer of the body of the uterus pT1aN0M0 IA stage. Surgical treatment from 12.15.2020 panhysterectomy; angiosarcoma of the anterior mediastinum with lesions of the manubrium, body of the sternum and the 1st rib on the left, invasion into the left brachiocephalic vein with the formation of a tumor thrombus in it, growing into the upper lobe of the left lung, T3N0M0, G1. Surgical treatment from 08.12.2021 resection of the manubrium and body of the sternum with resection of the anterior segments I, II, III ribs on both sides, resection of the left brachiocephalic vein, removal of an anterior mediastinal tumor, atypical resection of the upper lobe of the left lung en bloc, reconstruction of the sternum and ribs with an individual titanium 3D prosthesis. The patient was discharged from the hospital in a satisfactory condition.