Primary angiosarcomas of the anterior mediastinum:

Primary epithelioid hemangioendotheliomas and angiosarcomas of the pleura: a clinicopathological and immunohistochemical analysis of 13 cases

Thirteen cases of primary epithelioid hemangioendotheliomas (EHE) and epithelioid angiosarcomas (EA) of the pleura are presented. The patients were 7 men and 6 women between the ages of 34 and 65 years (mean: 47 years). The patients presented with non-specific symptoms of cough, dyspnea, and chest pain. Diagnostic imaging revealed the presence of either diffuse pleural thickening or pleural nodules involving the serosal surfaces. Open surgical biopsies were obtained in all cases. Histologically, eight tumors were characterized by the presence of a cellular proliferation composed of medium-sized epithelioid cells embedded in a myxohyaline stroma and a variable spindle cell component. Cellular atypia was mild to moderate and mitotic activity ranged from 1 to 2 per 2 mm2. Immunohistochemical stains for vascular markers, including CAMTA1 were positive, confirming a diagnosis of EHE. Five cases of epithelioid angiosarcomas were characterized by a neoplastic cellular proliferation admixed with areas of necrosis and hemorrhage and characterized by medium-sized epithelioid to spindle-shaped cells with eosinophilic cytoplasm, round to oval nuclei and prominent nucleoli. In addition, marked cytologic atypia and a mitotic activity ranging from 3 to 5 per 2 mm2 were identified. Immunohistochemical studies demonstrated positive staining for vascular markers; however, CAMTA1 was negative. Clinical follow-up obtained in eleven cases showed that all patients had died within 30 months post diagnosis. The current study highlights that even though it may be important to histologically separate EHE from EA for academic purposes, primary pleural origin of these tumors appears to portent an aggressive clinical behavior.

Primary epithelioid angiosarcoma of the mediastinum, cytomorphologic features of a rare entity-A case report and literature review

Epithelioid angiosarcoma (EA) is a highly aggressive vascular neoplasm. Primary mediastinal EA is extremely rare with only few cases reported in the English literature. We herein present a case of a 78-year-old patient, who was found to have a right superior mediastinal mass associated with mediastinal and hilar lymphadenopathy. Endobronchial ultrasound guided fine needle aspiration cytology of a station 4R lymph node revealed a cellular, discohesive malignant neoplasm displaying primarily epithelioid morphology with occasional spindled, plasmacytoid, and tumor giant cells. The tumor cells had ample eosinophilic cytoplasm with pleomorphic nuclei and prominent nucleoli. Vasoformative features were noted, exemplified by widespread cytoplasmic vacuoles containing neutrophils and rare red blood cells (hemophagocytosis) and vascular channels identified solely in the cell block. By immunohistochemistry, the tumor cells stained strongly positive for vimentin, positive for ERG, CD-31, FLI-1, and focally positive for pan-cytokeratin. The cytomorphological features and immunostaining patterns were diagnostic of EA. No history of malignancy was reported, and no other lesions were identified on imaging. The diagnosis of primary mediastinal EA on cytology and small biopsy specimens may be challenging due to the rarity of this tumor, limited diagnostic material, and overlapping morphologic features with other entities in the differential diagnosis. A high index of suspicion, especially in cases with vasoformative features, and utilization of ancillary studies can help establish the diagnosis.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

The Rarest of Rare Thymic Lesions: A 10-Year Surgical Pathology Experience

The thymus is a specialized primary lymphoid organ located in the midline pre-vascular mediastinum. The organ is the site of various pathological processes, neoplastic and not, whose rarity has not allowed in-depth studies on clinical or histological features of rarest and unusual variants. Herein, we report a 10-year Padova experience in the surgical pathology of the thymus, focusing on the pathological description of nonneoplastic lesions and rare epithelial and mesenchymal tumors recorded in our database, which comprises over 600 thymectomies. The extrapolated rare cases have been categorized into four groups that included 15 cysts, 18 carcinomas, 5 neuroendocrine tumors, and 2 soft tissue tumors. The cases are described from a clinical and pathological point of view and discussed in dedicated sections with a review of the most important literature. In this case, review series, we aim to update the epidemiology of these rare entities, improve diagnostic awareness, and finally, promote a collaborative network between referral centers.

Vasculogenic Mesenchymal Tumor: A Clinicopathologic and Molecular Study of 55 Cases of a Distinctive Neoplasm Originating From Mediastinal Yolk Sac Tumor and an Occasional Precursor to Angiosarcoma

We report 55 postchemotherapy resections of primary nonseminomatous mediastinal germ cell tumors with prominent vasculogenic features showing the formation of rudimentary to well-developed neoplastic vessels within primitive mesenchyme. These cases represented 25% of a cohort of 221 such specimens. The patients were 19 to 49 years old (mean, 28 y) and 98% had serological evidence of yolk sac tumor. The vasculogenic lesions, felt to represent a neoplastic reiteration of embryonic vasculogenesis in the splanchnic mesoderm of the yolk sac, were further subdivided into teratoma with vasculogenic stroma (n=9), vasculogenic mesenchymal tumor (VMT) (n=42, further classified into low grade [n=24] and high grade [n=18]), and angiosarcoma (n=4). The distinction of teratoma with vasculogenic stroma from VMT was based solely on the greater extent of VMT (exceeding 1 low power [×4 objective] microscopic field), with both categories showing a spectrum of vessels lined by atypical endothelium in a nonendothelial neoplastic stroma that often also generated vascular walls comprised of atypical smooth muscle. The angiosarcomas showed stratification of highly atypical endothelial cells or anastomosing vessels lined by nonstratified but cytologically similar endothelium. Immunohistochemical studies supported the generation of neoplastic vessels from the tumor stroma, most commonly by the development of stromal clefts showing reactivity for podoplanin, CD34, and occasionally ERG, followed by the gradual development from the clefts of thin-walled vessels that later became encircled by stromal cells showing smooth muscle differentiation by immunohistochemistry. Occasionally, round collections of stromal erythrocytes became surrounded by stromal cells to generate blood vessels. Fluorescence in situ hybridization showed chromosome 12p copy number increase in both the endothelial component and stromal component in 8/9 VMT cases and in 1/1 angiosarcoma. On follow-up, no patient with teratoma with vasculogenic stroma had evidence of a subsequent vascular tumor or sarcoma, whereas 8 of the 35 (23%) patients with VMTs (2 low grade and 6 high grade) and meaningful follow-up developed sarcoma (1 angiosarcoma, 2 rhabdomyosarcomas, and 5 not further characterized). The difference between low-grade and high-grade tumors was of borderline significance (P=0.058). Two of the 4 patients with angiosarcoma died of metastatic angiosarcoma, with the other 2 disease-free at 6.8 and 7 years. Compared with the 165 patients with follow-up and no vasculogenic lesions, there was a highly significant (P=4.3×10-5) association of any vasculogenic lesion with sarcomatoid tumors during the clinical course of VMT patients. In addition, 5/46 patients with follow-up and vasculogenic lesions (11%) died of either leukemia or myelodysplastic syndrome compared with 2 of 166 (1%) lacking them (P=0.0012). Three of the 5 patients had identifiable immature hematopoietic cells within their vasculogenic lesions, but 4 other VMT patients with these did not develop leukemia or myelodysplasia. We conclude: (1) vasculogenic lesions are frequent in postchemotherapy resections of primary mediastinal germ cell tumors with yolk sac tumor components; (2) they mostly consist of neoplastic vessels in a stroma that also generates neoplastic vascular walls of smooth muscle; (3) VMTs are associated with an increased incidence of sarcomas, even though most vasculogenic lesions in this context do not meet criteria for angiosarcoma; (4) the presence of vasculogenic lesions in postchemotherapy resections of primary mediastinal germ cell tumors place patients at increased risk for leukemia or myelodysplasia.

Sarcomas of the mediastinum with epithelioid morphology

While soft tissue sarcomas typically have a spindled or pleomorphic appearance, a subset of malignant soft tissue neoplasms can have a prominent epithelioid morphology. In complex anatomic sites such as the mediastinum, such tumors can often be mistaken for a carcinoma or mesothelioma. Frequent expression of cytokeratin staining can further confound the diagnostic process and familiarity with these entities can help prevent an erroneous diagnosis. Particular entities that have been reported to occur in the mediastinum with such features include dedifferentiated liposarcoma, pleomorphic liposarcoma, malignant peripheral nerve sheath tumor, synovial sarcoma, SMARCA4-deficient thoracic sarcoma, alveolar soft part sarcoma and clear cell sarcoma. Many of these tumors exhibit unique clinical, genetic, molecular or immunohistochemical features which allow for accurate characterization. For example, pleomorphic liposarcoma contains bizarre appearing lipoblasts and dedifferentiated liposarcoma exhibits MDM2 gene amplification that is typically confirmed by fluorescence in-situ hybridization. Malignant peripheral nerve sheath tumor will often arise in association with a nerve or neurofibroma. Synovial sarcoma consistently exhibits rearrangements involving the SS18 gene and SMARCA4-deficient thoracic sarcoma shows loss of SMARCA4 staining in the tumor cells. Alveolar soft part sarcoma demonstrates an ASPL-TFE3 fusion transcript. Clear cell sarcoma often shows an EWSR1-ATF1 fusion transcript. When encountering a sarcoma of the mediastinum with epithelioid features, familiarity with these and other characteristics can help insure a correct diagnosis.

Primary Intrathoracic Sarcomas: A Review of Cross-sectional Imaging and Pathology

The most common sarcomas in the thorax are metastasis from an extrathoracic primary malignancy. Primary intrathoracic sarcomas are rare albeit aggressive malignancies that are diagnosed on histopathology. Although a few imaging characteristics have been described that are common to sarcomas, it is still a diagnosis of exclusion as other tumors are much more common. Like elsewhere, primary thoracic sarcomas are also classified according to their histologic features. They are a rare group of tumors that can arise from the mediastinal structures, lung, pleura, or chest wall. On imaging, differentiating these from more common malignancies like lung cancer is difficult and often requires multimodality workup and tissue sampling. A few sarcomas are very specific to their locations, such as angiosarcoma in the right atrium, leiomyosarcoma in the pulmonary artery, where imaging has high accuracy for the diagnosis. Despite being nonspecific in a majority of cases, imaging plays a pivotal role in determining the organ of origin, tumor extent, invasion of adjacent structures, and thus help to assess the surgical resectability. Although sarcomas arising from chest wall are the most common primary sarcomas in the chest, they are excluded from this review to focus only on primary intrathoracic sarcomas. The article provides a comprehensive imaging and pathology review of the rare primary intrathoracic sarcomas, including but not limited to angiosarcoma, Kaposi sarcoma, fibrosarcoma, malignant transformation of fibrous tumor of pleura, sarcomatoid mesothelioma, leiomyosarcoma, and malignant small round blue cell tumors.Key points:Primary intrathoracic sarcomas are rare but clinically important.Imaging helps to determine local extent, invasion, metastases and appropriate site/mode of biopsy.Role of pathology is paramount in diagnosis and guiding treatment based on immunogenetic/molecular typing.

A rare case of primary angiosarcoma of the anterior mediastinum

A 32-year-old male patient was initially diagnosed with fibrosing mediastinitis. The patient subsequently developed severe dyspnea and was further diagnosed with constrictive pericarditis due to the extent of fibrosing mediastinitis around the heart. Therefore, the patient underwent surgical resection of the fibrotic tissue in the anterior mediastinum including the pericardium and the pleura. Postoperative histological and immunohistochemical analyses revealed angiosarcoma. Seven years after the diagnosis, he is still alive. Herein, we report a case of atypical primary angiosarcoma of the anterior mediastinum causing constrictive pericarditis and restrictive pulmonary dysfunction.

Vascular tumors of the mediastinum

Vascular tumors represent only a sliver of all tumors affecting the mediastinum, but they pose diagnostic challenges due to significant overlap among entities, ever-evolving classification schemes, and the exquisite rarity of some of the entities not only in the mediastinum but in pathology practice as a whole. Most of the vascular tumors are better known to the practice of soft tissue pathology, from which some of the knowledge of clinical behavior can be extrapolated. For example, the stratification of epithelioid hemangioendothelioma (EHE) into two biologically separate categories has effectively translated from the somatic soft tissues to the thorax. For other entities, the effective validation of soft tissue parameters is hindered by the small numbers of reported mediastinal cases. Many of the treatment modalities have also transferred over, with the key differences resting on the difficulty in achieving complete surgical resection for mediastinal tumors as opposed to those in the somatic soft tissues. Accordingly, systemic drug therapies have emerged as attractive options for some of the mediastinal vascular tumors, such as kaposiform hemangioendothelioma (KHE) and Kaposi sarcoma (KS). The categories presented herein mirror the classification scheme set forth by the 5th Edition WHO Classification of Soft Tissue and Bone Tumors. This review focuses on the biologically aggressive vascular neoplasms while limiting discussion of the benign entities to relevant comparisons in the differential diagnoses. While distinguishing among the benign entities has academic importance, in practice, the stakes are far higher for diagnosing the biologically aggressive tumors given their marked heterogeneity in clinical outcomes. Practical advice for problem areas in pathology will be reviewed alongside tumor pathobiology, including the latest in molecular diagnostics.

Angiosarcoma originating in the anterior mediastinum: A case report

RATIONALE

Angiosarcomas are malignant vascular tumors, and angiosarcoma occurring in the anterior mediastinum is rare. Here we report a case of angiosarcoma that originated in the anterior mediastinum treated with surgery, followed by radiotherapy and synchronous chemotherapy.

PATIENT CONCERNS

A 56-year-old female was admitted to our hospital with chest pain for 3 days. Chest computerized tomogram (CT) examination showed a heterogeneous mass in the anterior superior mediastinum, and after injection of contrast agent, the mass showed obvious heterogeneous enhancement. Magnetic resonance imaging (MRI) with T1 weighted image (T1WI) showed isointensity and T2 weighted image (T2WI) showed heterogeneous signal intensity, the mass showed an obvious heterogeneously enhancement after intravenous administration of contrast material.

DIAGNOSIS AND INTERVENTIONS

Surgical resection operation was carried out. According to its morphologic and immunohistochemic feature of tumor cells which expressing CD31, CD34, and ERG, the tumor was categorized as an angiosarcoma. After operation, the patient received radiotherapy and synchronous chemotherapy.

OUTCOMES

At present, 8 months postoperatively, no signs of recurrence have been observed.

LESSONS

Although angiosarcoma in anterior mediastinum is rare, when a mass located in this area, a more careful immunohistological analysis should be performed to avoid overlooking the presence of angiosarcoma.

Development of angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy

Herein, we report a case of an angiosarcoma in a mediastinal non-seminomatous germ cell tumor that exhibited growing teratoma syndrome during chemotherapy. A 26-year-old man presented with a giant anterior mediastinal mass, which was diagnosed as a non-seminomatous germ cell tumor. The patient was administered three cycles of chemotherapy (bleomycin, etoposide, and cisplatin), but the mass grew despite normalization of tumor markers. Massive bleeding during thoracic surgery resulted in incomplete resection, and the mass was clinically and pathologically diagnosed as growing teratoma syndrome (only mature teratoma). The residual mass continued to grow, and complete resection was subsequently achieved after a detailed analysis of its vascular anatomy using angiography. The final pathological findings revealed angiosarcoma, which indicated a rare somatic type of mediastinal non-seminomatous germ cell tumor.

[Mesenchymal tumors of the mediastinum]

Mesenchymal neoplasms of the thymus and mediastinum account for only 2 % of neoplasms of the mediastinum and are therefore very rare. With very few exceptions the histology, immunohistochemistry and (based on current knowledge) molecular biology of mediastinal soft tissue tumors are not different from their counterparts in other organs. Characteristic features are more concerned with clinical epidemiological and therapeutic aspects as well as the multitude of possible differential diagnoses. With the exception of organ-specific tumors, such as gastrointestinal stromal tumors (GIST), virtually all entities encountered in peripheral soft tissues can also arise in the mediastinum. Primary mediastinal soft tissue sarcomas (STS) must be distinguished from secondary radiation-induced STS after irradiation, e. g. for breast cancer and Hodgkin's lymphoma and from STS arising as somatic type malignancies in mediastinal germ cell tumors.

Angiosarcoma arising in association with vascular Dacron grafts and orthopedic joint prostheses: clinicopathologic, immunohistochemical, and molecular study

Angiosarcoma may rarely arise near an inert foreign body material including vascular grafts and metal joint prostheses. Sixteen such cases have been reported since 1972 but mostly in the radiologic or surgical literature without detailed histologic or molecular analyses. We herein describe the clinicopathologic and molecular features of 2 new cases and reanalyzed 3 previously reported cases of angiosarcoma that developed in association with Dacron grafts for vascular repair (n=3) or related to orthopedic metal prostheses for joint replacement (n=2). All patients were men aged 50 to 84 years (median, 71 years). Mean time to development of angiosarcoma was 9 years (range, 4.6-17 years). Symptoms were recurrent bleeding/loosening of prosthesis for suspected infection (in the joint prosthesis cases) and fatigue, weight loss, and abdominal symptoms in the Dacron-associated cases. Four patients died of disease within 1 to 24 months (mean, 8 months). One patient was alive after radical surgery, radiochemotherapy, and embolization of pulmonary metastases (17 months). Histologically, all tumors were high-grade epithelioid neoplasms with a predominant solid growth pattern and variable vasoformation. All tumors expressed CD31, ERG, FLI-1, and variably pancytokeratin (diffuse in 3 cases), but none expressed D2-40, MDM2, or CDK4. Fluorescence in situ hybridization analysis revealed no MDM2 or CDK4 alterations. MYC was expressed in all cases, but only 1 case was MYC amplified by fluorescence in situ hybridization. Angiosarcomas are exceedingly rare fatal complications of long-standing metal and Dacron prostheses. Awareness of their morphology and frequent cytokeratin expression is necessary to avoid misdiagnosis as metastatic carcinoma. Limited awareness of their existence explains delayed clinical diagnosis in most of cases. Absence of MDM2/CDK4 alterations underlines their distinction from intimal-type sarcomas.

Mesenchymal tumours of the mediastinum--part II

This is the second part of a two-part review on soft tissue tumours which may be encountered in the mediastinum. This review is based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart and provides an updated overview of mesenchymal tumours that have been reported in the mediastinum.

Clinical, histological, and immunohistochemical features of a mandibular metastasis from a primary cardiac angiosarcoma

Primary cardiac angiosarcoma is an extremely rare malignant tumor. Distant metastases are common at the time of diagnosis but have never been reported in the jaw. A 45-year-old female patient with primary cardiac angiosarcoma was referred for dental care due to pain in the mandibular alveolar ridge. Oral examination revealed a red-violet lesion that was soft on palpation and had been present for 3 months. Histological analysis confirmed the diagnosis of metastatic cardiac angiosarcoma. The patient died of multiple metastases.

[A case of mediastinal angiosarcoma]

INTRODUCTION

Mediastinal angiosarcoma is a rare intrathoracic tumour and the therapeutic approach remains poorly codified.

CASE REPORT

We report the case of a 65-year-old female patient presenting with chest pain. Further exploration revealed an anterior mediastinal mass with pericardial invasion. Transthoracic biopsy gave the diagnosis of angiosarcoma. Multimodal treatment with neoadjuvant chemotherapy (doxorubicin 20 mg/m(2), Ifosfamide 2500 mg/m(2), Uromitexan® 2500 mg/m(2)) and surgery followed by adjuvant radiotherapy has led to remission of the tumour that has persisted for 12 months.

CONCLUSION

Systematic recording of such conditions in dedicated registries could contribute to enhance the description of the clinical and pathological characteristics, thus helping define the principles of specific management.