Malignant epithelioid vascular tumors of the pleura: report of a series and literature review

Nonmesothelial Spindle Cell Tumors of Pleura and Pericardium

Spindle cell lesions of the pleura and pericardium are rare. Distinction from sarcomatoid mesothelioma, which has a range of morphologic patterns, can be difficult, but accurate diagnosis matters. This article provides practical guidance for the diagnosis of pleural spindle cell neoplasms, focusing on primary lesions.

Mesenchymal tumours of the pleura: review and update

Primary mesenchymal tumours of the pleura are uncommon and can be diagnostically challenging due to their overlapping histopathologic and immunophenotypic features. Herein we discuss selected mesenchymal tumours of the pleura, including solitary fibrous tumour, calcifying fibrous tumour, desmoid fibromatosis, synovial sarcoma, schwannoma, malignant peripheral nerve sheath tumour, inflammatory myofibroblastic tumour, follicular dendritic cell sarcoma, epithelioid hemangioendothelioma, and desmoplastic small round cell tumour. We review their clinicopathologic characteristics, along with an update on the relevant immunohistochemical and molecular features.

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 malignant epithelioid hemangioendothelioma of the pleura: A review and report of a novel case

Epithelioid hemangioendothelioma is considered an uncommon tumor originating from vascular tissues. Although this disease is an extremely rare malignant cancer, its pleural subtype is even less common. We discuss a 68‐year‐old man with isolated pleural epithelioid hemangioendothelioma, along with a literature review of all similar cases.

Angiosarcoma of breast and chest wall complicated with tuberculous empyema: A case report

Angiosarcoma is a highly malignant endothelial tumor, accounting for 1% to 2% of soft tissue sarcomas. The most common site of the disease is the skin, accounting for approximately 60% of cases, especially the skin of the head. It can also occur in soft tissue, bone, and retroperitoneum. However, angiosarcomas of the breast and chest wall are rare. Here, we report a 44‐year‐old woman who was admitted to hospital with encapsulated empyema. She was subsequently diagnosed with angiosarcomas of the breast and chest wall with tuberculous empyema. At the same time, we also reviewed the current research progress in angiosarcoma of the breast and chest wall to explore better treatment options for these patients.

Characteristics and outcomes of primary pleural angiosarcoma: A retrospective study of 43 published cases

Primary pleural angiosarcoma (PPA) is an extremely rare malignancy for which there is no consensus on treatment. The clinical course of PPA is usually quickly fatal, regardless of the treatment used.We summarized and evaluated a relatively large population of published PPA cases to assess prognostic factors, diagnostic approaches, treatment methods and clinical outcomes. Using the CNKI, Embase, and PubMed databases, literature published in English and Chinese from 1988 through 2020 was searched using the terms "primary pleural angiosarcoma," "pleural angiosarcoma," and "pleuropulmonary angiosarcoma."A total of 43 patients with PPA were identified in retrospective case series and case reports. The median age at diagnosis was 64 years (range 24-87 years), and the median overall survival was 4 months (range 0.1-180 months). Approximately 80% of patients died from PPA within 10 months of diagnosis, and the 2-year survival rate was approximately 4.4%. In univariate analyses, the presence of pleural effusion and hemothorax were significant predictors of decreased survival, with hazard ratios (HRs) of 2.7 (P = .04) and 3.3 (P = .006), respectively. Sixteen patients received no therapy, and their prognosis was worse than patients who did receive therapy (P = .019). Radiation therapy improved survival more than no radiation therapy (P = .007). Patients appeared to derive clinical benefit from chemotherapy (P = .048). However, tumor resection did not seem to provide a survival benefit (P = .051). In multivariate analysis, tumor resection, and radiation were independent, statistically significant, positive predictors of better survival, with HRs of 0.3 (P = .017) and 0.1 (P = .006), respectively. The presence of hemothorax was an independent predictor of worse prognosis (P = .006).Primary angiosarcoma of the pleura is a rare, poorly understood malignancy with a poor prognosis; hence, the clinical spectrum of PPA is not completely defined. By multivariate analysis, this retrospective study showed a survival benefit of tumor resection or radiation therapy, and the presence of hemothorax was a significant prognostic factor for poor outcomes.

Primary pleural epithelioid angiosarcoma treated successfully with anti-PD-1 therapy: A rare case report

RATIONALE

Primary pleural angiosarcoma (PPA) is an extremely rare malignancy for which there is no consensus on treatment. The clinical course of PPA is usually quickly fatal, regardless of the treatment used.

PATIENT CONCERNS

We describe the rare case of a 52-year-old man who presented initially with hemoptysis and received emergency surgery for the primary.

DIAGNOSES

He received a confirmed diagnosis of primary pleural angiosarcoma (PPA) by postoperative pathology and was subsequently treated with radiotherapy and chemotherapy, but had failed and was intolerant to chemotherapy.

INTERVENTIONS

The patient had 5% tumor PD-L1 positivity with 22C3 pharmDx and received pembrolizumab (200 mg every 21 days) for 13 cycles.

OUTCOMES

The disease remained well controlled according to the RECIST 1.1. criteria. He is currently under observation and waiting to start the next cycle of immunotherapy.

LESSON

Our case report suggests that the use of anti-PD-1 therapy does show efficacy in the treatment of PPA and may provide a viable treatment option for patients.

Primary pleural epithelioid angiosarcoma manifesting as a loculated hemothorax: A case report and literature review focusing on CT findings

Primary pleural angiosarcoma (PPA) is an extremely rare and clinically aggressive tumor. We report the case of a 66-year-old man having PPA with chest computed tomography (CT) scan showing a large oval-shaped, nonenhancing high attenuation cystic mass in the left hemithorax. Morphological and immunohistochemical findings supported the diagnosis of epithelioid angiosarcoma. Pleural angiosarcoma should be considered in the differential diagnosis of spontaneous hemothorax manifesting as high attenuation loculated pleural fluid on CT.

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.

Primary pleural angiosarcoma: Case report and literature review

Primary pleural angiosarcoma is an exceptionally rare malignancy of pleura originating from the vascular endothelial cells. Here, we present a 70-year-old African-American female who presented with 1-month history of dyspnea on exertion, loss of appetite, and loss of weight along with left-sided pleuritic chest pain. Evaluation revealed hemorrhagic pleural effusion in the left pleural cavity. Computed tomography of the chest performed after therapeutic thoracocentesis revealed left upper lobe lung mass along with multiple nodules in right lung. Mass was biopsied at video-assisted thoracoscopy. Histopathology was consistent with high-grade angiosarcoma. Endothelial origin of the tumor cells was confirmed with positive immunohistochemical staining with CD31 antibodies. Our patient was diagnosed with primary pleural angiosarcoma metastatic to the lung. She opted for palliative care and had a rapidly declining clinical course and expired within 5 weeks of the diagnosis. Here, we present a case report and review the relevant literature.

The Diagnosis of Pleural Tumors Other Than Mesothelioma

CONTEXT

- Pleural pathology has been dominated by discussions relating to the diagnosis, prognosis, etiology, and management of malignant mesothelioma. However, there exists a diverse group of other neoplasms that involve the pleura; the most common by far is metastatic carcinoma, usually of pulmonary origin. Other metastatic tumors of varied histogenesis do occur but are less common. Primary pleural neoplasms other than diffuse malignant mesothelioma are either uncommon or rare and have received less attention.

OBJECTIVE

- To provide a review of those diverse tumors that can involve the pleura other than mesothelioma in order to facilitate their accurate diagnosis.

DATA SOURCES

- Review of relevant literature published via PubMed and other search engines.

CONCLUSIONS

- A wide variety of tumors can involve the pleura. In most cases, the approach of considering the morphologic features with appropriate immunohistochemistry, in the correct clinical context, allows for a confident diagnosis. For a number of those soft tissue tumors that are well recognized in the pleura, such as solitary fibrous tumor, desmoid-type fibromatosis, synovial sarcoma, and epithelioid hemangioendothelioma, novel markers now exist based on an understanding of the individual tumors' molecular characteristics. Primary pleural lymphomas are rare with poor prognosis. They represent localized specific diffuse large B-cell lymphomas, with either post-germinal center B-cell or plasma cell lineage, arising in the context of either immunodeficiency or immune sequestration and with viral infection.

Updates in Effusion Cytology

Effusion cytology plays multiple roles in the management of benign and malignant disease, from primary diagnosis to tissue allocation for ancillary diagnostic studies and biomarker testing of therapeutic targets. This article summarizes recent advances in pleural effusion cytology, with a focus on the practical application of immunohistochemical markers, cytogenetic techniques, flow cytometry, and molecular techniques for the diagnosis and management of primary and secondary neoplasms of the pleura.

Pulmonary epithelioid angiosarcoma responsive to chemotherapy: A case report

Primary pulmonary epithelioid angiosarcoma (AS) is an extremely rare cancer with a poor prognosis. The presenting symptoms and imaging results are nonspecific and hold similarities with more common lung pathology, contributing to missed or delayed diagnosis. Complementing radiological imaging with patient information, such as presenting symptoms and exposures, is important for early consideration of pulmonary epithelioid AS. Even with supportive imaging findings and clinical suspicion for pulmonary epithelioid AS, the most reliable and definitive method for diagnosis is through immunohistochemistry. We describe the case of a 65-year-old patient who presented with dyspnea, cough, and hemoptysis in whom pauci-immune vasculitis was initially suspected before immunohistochemical diagnosis of primary pulmonary epithelioid AS. Due to the rarity of this disease, treatment options have not been well-studied and consist of any combination of surgical resection, chemotherapy, and radiation therapy. Although typically poorly responsive to chemotherapy, our patient achieved a reduction in size of his pulmonary nodules after a course of steroids followed by cyclophosphamide and was later maintained with gemcitabine and docetaxel until his death nearly a year after presentation.

Pleural epithelioid angiosarcoma with lymphatic differentiation arisen after radiometabolic therapy for thyroid carcinoma: immunohistochemical findings and review of the literature

Background

Pleural angiosarcoma is a rare tumor that causes diffuse pleural thickening and effusion, mimicking mesothelioma. Immunohistochemistry is needed to highlight endothelial differentiation. We describe the first case of pleural angiosarcoma with lymphatic differentiation following radiometabolic therapy for thyroid carcinoma.

Case presentation

A 50-year-old man showed diffuse pleural thickening and effusion. Nine years earlier, he underwent thyroidectomy and radiometabolic therapy for thyroid carcinoma with lymph node metastases. Histologically, the tumor consisted of a solid proliferation of atypical epithelioid cells and anastomosed vascular spaces, lacking of red blood cells and containing Alcian blue positive material. The tumor showed positive immunostaining for Vimentin, CD31, CK7, D2–40, c-MYC, Ki67, focal positivity for PanCK, and negative immunostaining for Factor VIII, CD34, WT1, CK5/6, Calretinin, EMA, HBME-1, CEA, p63, EpCAM, Bcl-2, TTF1 and Thyroglobulin. CD99 showed a granular/paranuclear pattern of positivity. The histological and immunohistochemical features were consistent with “pleural angiosarcoma with lymphatic differentiation, epithelioid variant”.

Discussion and conclusions

Epithelioid angiosarcoma with lymphatic differentiation is very rare and aggressive. Moreover, the positivity for c-MYC suggests the relationship with radiometabolic therapy. To our knowledge, this is the first case of pleural c-MYC-positive angiosarcoma with lymphatic differentiation reported in the literature and the first one arisen after radiometabolic therapy for thyroid carcinoma.

Vasculogenic mimicry in malignant mesothelioma: an experimental and immunohistochemical analysis

Vasculogenic mimicry, the process in which cancer cells form angiomatoid structures independent of or in addition to host angiogenesis has been recorded in several otherwise non-endothelial malignant neoplasms. This study describes evidence of routine vascular mimicry by human mesothelioma cell lines in vitro, when the cell lines are cultured alone or co-cultured with human umbilical vascular endothelial cells, with the formation of angiomatoid tubular networks. Vasculogenic mimicry is also supported by immunohistochemical demonstration of human-specific anti-mitochondria antibody labelling of tumour-associated vasculature of human mesothelioma cells xenotransplanted into nude mice, and by evidence of vascular mimicry in some biopsy samples of human malignant mesotheliomas. These studies show mosaic interlacing of cells that co-label or label individually for immunohistochemical markers of endothelial and mesothelial differentiation. If vascular mimicry in mesothelioma can be characterised more fully, this may facilitate identification of more specific and targeted therapeutic approaches such as anti-angiogenesis in combination with chemotherapy and immunotherapy or other therapeutic approaches.

Primary pleural angiosarcoma associated with pneumoconiosis: An autopsy case

We report a case of pleural angiosarcoma in an adult male patient confirmed by autopsy and possibly associated with pneumoconiosis. The lesion was characterized by thickened pleura of both lungs with nodular tumors. Histologically, the tumor was composed of spindle-to-polygonal epithelioid cells that were positive for CD31, CD34, vimentin, and cytokeratin on immunohistochemical staining but were negative for calretinin. Further examination revealed mix-dust pathological findings consistent with the existence of pneumoconiosis; dystrophic ossification, anthracosis, and fractal small dust particles were observed in the lung parenchyma and a hilar lymph node. The current case suggests that pneumoconiosis-associated pathologies may be risk factors for the development of angiosarcoma in the pleura.

Thoracic epithelioid malignant vascular tumors: a clinicopathologic study of 52 cases with emphasis on pathologic grading and molecular studies of WWTR1-CAMTA1 fusions

Malignant thoracic epithelioid vascular tumors are an uncommon and heterogenous group of tumors that include low-grade to intermediate-grade epithelioid hemangioendothelioma (EHE) and high-grade epithelioid angiosarcoma (EAS). We examine the morphologic and immunohistochemical features of 52 malignant epithelioid vascular tumors (10 low-grade EHE, 29 intermediate-grade EHE, and 13 EAS) involving the thorax (lung, pleura, mediastinum, heart, great vessels) including cases with exclusively thoracic disease (35) and with multiorgan disease including the thorax (17). Intermediate-grade EHE differs from low-grade EHE by the presence of necrosis, increased mitotic activity, and increased atypia. Morphologic features such as intranuclear inclusions, intracytoplasmic vacuoles, and stromal changes (chondroid, myxoid, or hyalinized stroma) are seen more frequently in EHE, whereas blood lakes, proliferation of slit-like vessels, and prominent nucleoli favor EAS. Fluorescence in situ hybridization analysis showed CAMTA1-WWTR1 fusions in 4/7 low-grade and 23/23 intermediate-grade EHE (P<0.001). In EAS, CAMTA1 rearrangement was negative in all cases, whereas a WWTR1 complex abnormality was found in 1/5 cases (P<0.001). This offers an objective means of differentiating intermediate-grade EHE from EAS, especially on limited biopsies. All cases show expression of at least 1 vascular marker, which allows differentiation from primary thoracic epithelial malignancies, although keratin expression is a potential pitfall with 29% of EHE and 25% of EAS showing keratin expression. Survival analysis shows that higher tumor grade for all tumors (P=0.026) as well as lung and pleural tumors only (P=0.010) and the presence of pleural involvement in lung and/or pleural tumors (P=0.042) correlate with poor prognosis.

Pleuropulmonary angiosarcoma involving the liver, the jejunum and the spine, developed from chronic tuberculosis pyothorax: Multidisciplinary approach and review of literature

Pleuropulmonary angiosarcomas are very rare, with less than fifty cases reported in the literature. In most cases, the etiology is unknown but the presence of a chronic tuberculous pyothorax has been reported in several Asian case reports as a possible risk factor. We report the case of a Caucasian 68-year old man who presented with a pleuropulmonary angiosarcoma that arose from a chronic tuberculous pyothorax and which involved the ribs and the vertebrae, the psoas muscle, and the jejunum. The patient received adapted anti-tuberculosis treatment, embolization of the mass in the small bowel, palliative external beam radiotherapy on the spine and systemic chemotherapy with liposomal non-pegylated doxorubicin and ifosfamide. With this multidisciplinary approach the patient's symptoms were well controlled and he achieved a complete metabolic response after six cycles of chemotherapy. Unfortunately, the patient died after eight months from the beginning of chemotherapy due to an acute lung injury secondary to extensive bilateral interstitial infiltrates. Opportunistic pathogens or drug-induced lung toxicity were the most probable causes. Treatment with liposomal non-pegylated doxorubicin and ifosfamide could be a reasonable option in pleuropulmonary angiosarcoma but it should be validated in clinical trials. Chronic pyothorax seems to be a predisposing factor for the development of pleural angiosarcoma but further investigations are required to assess a causal association.

Primary pleural angiosarcoma in a 63-year-old gentleman

Primary pleural angiosarcomas are extremely rare. As of 2010, only around 50 case reports have been documented in the literature. Herein, we report the case of a 63-year-old gentleman who presented with a 3-month history of right-sided chest pain, dyspnea, and hemoptysis. Chest X-ray showed bilateral pleural effusion with partial bibasilar atelectasis. Ultrasound-guided thoracocentesis showed bloody and exudative pleural fluid. Cytologic examination was negative for malignant cells. An abdominal contrast-enhanced computed tomography (CT) scan showed two right diaphragmatic pleural masses. Whole-body positron emission tomography/computed tomography (PET/CT) scan showed two hypermetabolic fluorodeoxyglucose- (FDG-) avid lesions involving the right diaphragmatic pleura. CT-guided needle-core biopsy was performed and histopathological examination showed neoplastic cells growing mainly in sheets with focal areas suggestive of vascular spaces lined by cytologically malignant epithelioid cells. Immunohistochemical analysis showed strong positivity for vimentin, CD31, CD68, and Fli-1 markers. The overall pathological and immunohistochemical features supported the diagnosis of epithelioid angiosarcoma. The patient was scheduled for surgery in three weeks. Unfortunately, the patient died after one week after discharge secondary to pulseless ventricular tachycardia arrest followed by asystole. Moreover, we also present a brief literature review on pleural angiosarcoma.

Rare pleural tumors

Primary pleural tumors other than mesothelioma account for fewer than 1% of all lung cancers, and consequently they pose diagnostic and management challenges. Their treatment must be targeted toward the specific tumor type and is often quite different from the treatment for mesothelioma or metastases. Despite the best efforts at diagnosing and treating these tumors, the prognosis associated with some of the benign and many of the malignant variants of these tumors remains poor. In this review, we describe the radiologic and pathologic features of the less common primary pleural tumors and propose a diagnostic approach to their evaluation.

Epithelioid Lesions of the Serosa

Context.—Diagnosing epithelioid serosal lesions remains a challenge because numerous different processes—primary or secondary, benign or malignant—occur in body cavities, some of which are very rare.

Objectives.—To review the newest literature and to describe the morphologic criteria and immunohistochemical markers that are useful for distinguishing epithelioid serosal lesions.

Data Sources.—Previously published literature concentrating on the newest research findings. Earlier reviews are principally referred to for established diagnostic criteria.

Conclusions.—Immunohistochemistry with a panel of antibodies has made the diagnosis of epithelioid serosal lesions very reliable. When deciding on antibodies used in differential diagnosis, it is important to consider tumor location, clinical and radiologic information, and morphologic features. Immunohistochemistry is less useful in the differential diagnosis of benign versus malignant mesothelial lesions. The diagnosis of benign versus malignant mesothelial proliferations still relies on the histologic criteria of invasion.

Primary pleural angiosarcoma as a mimicker of mesothelioma: a case report **VS**

Primary pleural angiosarcoma is a rare and clinically aggressive tumor. Patients usually present with chest pain, dyspnea, hemoptysis and/or cough. Radiologic studies reveal diffuse pleural thickening and pleural effusion with or without mass lesion. The clinical and radiological features both resemble those of mesothelioma, and its definite diagnosis requires careful histologic examination. However, frequent epithelioid feature and immunoreactivity to cytokeratin in primary pleural angiosarcoma further complicate the pathologic diagnosis. The use of proper immunohistochemical stains is often needed to support endothelial differentiation in the tumor cells and to exclude metastatic carcinoma and mesothelioma. We report the case of a 49-year-old male patient with primary pleural angiosarcoma, who presented with initial hemothorax, followed by a rapid progress to an inoperable status.

[A case of primary pleural angiosarcoma metastasing to the bladder]

The patient was a 79-year-old man who underwent right extrapleural lucite ball plombage for pulmonary tuberculosis at aged 19. He was followed BPH with medication from May 2008 at our hospital. He presented with macrohematuria in January 2010, but cystoscopy and CT scan showed no significant abnormalities. He was admitted to complaining of general fatigue and anemia in February 2010. TURBT was performed 10 days after admission, and showed the bleeding sites with oozing in mucosa at the bilateral and posterior wall of the bladder. Neither CT nor cytological examinations were helpful in diagnosing this disease, although histological observation implied a possibility of malignant vasoformative tumor. He died one month after admission. Autopsy revealed a huge bloody mass at the right upper thoracic wall and same metastatic tumors of both adrenals, the bone, the stomach and the urinary bladder. Microscopic examination revealed that atypical cells had proliferated and formed vascular structures, which were stained positively with CD31, and vimentin. Finally, the diagnosis was made of pleural angiosarcoma and multiple metastasis. Metastatic angiosarcoma of the bladder is very rare and difficult to make definite diagnosis, however we have to keep in mind the presence of this disease.

Pleural epithelioid hemangioendothelioma in an elderly patient. A case report and review of the literature

Pleural epithelioid hemangioendothelioma is a really rare tumor of vascular origin and potentially aggressive behavior. We report the case of an 85 years old male patient diagnosed of pleural epithelioid hemangioendothelioma, taking advantage to review exhaustively literature and therapy for the disease.

[Epithelioid hemangioendothelioma of the pleura - A rare presentation of a clinical case]

Epithelioid Hemangioendothelioma (EHE) is a vascular tumour with rare pleural presentation. As there are a small number of cases described in the literature the authors present the case of a 65 -year -old woman, who was admitted to the Emergency Department for a right -sided chest pain, which progressed over 7 months, after a thoracic trauma. The chest X -ray showed signs of a moderate right -sided pleural effusion. A pleural -pulmonary biopsy carried out by toracotomy established the histological diagnosis of EHE of the pleura. Due to the locally advanced stage of the tumour, chemotherapy with carboplatin and etoposide was prescribed and the patient died 6 months later. This case confirms that pleural EHE has an aggressive behaviour, similar to an angiossarcoma, with a median survival of only a few months after diagnosis.

Sarcomatoid neoplasms of the lung and pleura

Sarcomatoid neoplasms of the lung and pleura are rare tumors that present a complex differential diagnosis, making them challenging for surgical pathologists. In the lung, the main tumors are the sarcomatoid carcinomas, including pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. They are characterized by histologic heterogeneity; molecular data support their origin from a pluripotent stem cell that undergoes neoplastic transformation with divergent epithelial and sarcomatous differentiation. Diagnosis is difficult in small biopsy specimens and typically requires a resection specimen. Despite the presence of sarcomatoid features, these tumors are classified as lung carcinomas. Pulmonary blastomas must be distinguished from pleuropulmonary blastomas, which are a unique type of thoracic sarcoma typically occurring in young children. In the pleura, the main tumors to consider are the sarcomatoid and desmoplastic types of malignant mesothelioma, solitary fibrous tumor, and desmoid tumor. While light microscopy is sufficient to diagnose most of these tumors, immunohistochemistry can be useful in selected settings. In particular, it can aid to confirm epithelial differentiation in spindle cell carcinomas and the presence of rhabdomyosarcoma in sarcomatoid carcinomas, mesotheliomas, or pleuropulmonary blastomas. For sarcomatoid and desmoplastic mesothelioma, keratin is the most useful stain because it can highlight invasive growth and mesothelial markers are positive in only the minority of cases. Clinical and radiologic correlation is needed to separate some pleomorphic carcinomas with pleural involvement from sarcomatoid malignant mesothelioma, since these poorly differentiated tumors may not express the usual immunohistochemical markers for carcinoma or mesothelioma.

Plasma cell myeloma presenting with diffuse pleural involvement: a hitherto unreported pattern of a new mesothelioma mimicker

We described 2 cases of plasmacytoma presenting with a preponderant involvement of the pleural membranes simulating clinically, radiologically, and on gross pathologic inspection a primary mesothelioma. The patients were an 80-year-old man and a 45-year-old woman. In both cases, the clinical presentation was that of a serosal tumor, including effusions and pleural thickening. In the former, the serosal infiltration raised the suspicion of mesothelioma reinforced by history of occupational exposure to asbestos. Patient general condition deteriorated rapidly. Postmortem examination revealed unilateral encasing of the lung within a thick, irregular neoplastic rind. In addition, tumoral involvement was seen in the homolateral third rib and the clavicle. Histologic examination of pleural masses demonstrated diffuse infiltration by highly atypical, pleomorphic plasma cells with kappa chain restriction. In the second case, clinical presentation was also suspicious of mesothelioma. Nonetheless, a pleural biopsy specimen showed irregular sheets of plasma cells showing kappa light chain restriction. A bone marrow aspirate was also positive for abnormal plasma cell infiltrates. Despite chemotherapy, the patient died 4 months after presentation. Although rarely, it seems that plasmacytoma may present with an exclusive or preponderant pleural involvement; and it may therefore be added to the list of pseudomesotheliomatous tumors.

The transcription factor LMO2 is a robust marker of vascular endothelium and vascular neoplasms and selected other entities

The transcription factor LMO2 is involved in vascular and hematopoietic development and hematolymphoid neoplasia. We have demonstrated that LMO2 is expressed nearly ubiquitously in native and neoplastic vasculature, including lymphatics. LMO2 reactivity is otherwise virtually absent in nonhematolymphoid tissues except in breast myoepithelium, prostatic basal cells, and secretory phase endometrial glands. Vasculature is LMO2- in adult and fetal heart, brain of older adults, hepatic sinusoids, and hepatocellular carcinoma. LMO2 is uniformly expressed in benign vascular and lymphatic neoplasms and in most malignant vascular neoplasms with the exception of epithelioid vascular neoplasms of pleura and bone. Among nonvascular neoplasms, LMO2 reactivity is present in giant cell tumor of tendon sheath, juvenile xanthogranuloma, a subset of gastrointestinal stromal tumors, small round blue cell tumors, and myoepithelial-derived neoplasms. The restricted expression pattern, nuclear localization, and crisp staining of LMO2 in paraffin blocks make it an attractive candidate for the diagnostic immunohistochemistry laboratory.

Pleural epithelioid hemangioendothelioma

Epithelioid hemangioendothelioma (EHE) is a rare tumor of vascular origin. While it can be found in any tissue, it is most often found in lung and liver and usually has an intermediate behavior. EHEs originating from pleural tissue have been less frequently described than those from other sites. Furthermore, to date, all of the cited pleural EHEs were described as highly aggressive. In the present report, we describe a rare case of pleural EHE extending to lung and bone in a 31-year-old woman. The histological diagnosis was confirmed by both conventional examination and immunohistochemistry. Her disease stabilized during the 4th course of adriamycin (45 mg/m(2), day 1-3), dacarbazine (300 mg/m(2), day 1-3) and ifosfamide (2,500 mg/m(2), day 1-3) with mesna, and she survived for 10 months after the diagnosis.

Problems in mesothelioma diagnosis

Many centres are now seeing increasing numbers of patients with malignant mesothelioma. This presents pathologists involved in making the diagnosis with a number of problems, which can be divided into those encountered in making the distinction between mesothelioma and benign changes and those experienced in separating mesotheliomas from other types of epithelial and connective tissue tumours. Immunohistochemistry plays a major role in helping to make the diagnosis, but it should be interpreted with due regard to the clinical setting and radiological features, and with a knowledge of the wide morphological variations seen in mesothelioma. This review identifies some of these problems and addresses the uses and limitations of immunohistochemistry in different situations. It includes a discussion of some of the less common variants of mesothelioma and other pleural-based tumours that enter into the differential diagnosis.

Primary epithelioid angiosarcoma of the thyroid: an infrequent malignant thyroid tumor

We present a case of epithelioid angiosarcoma of the thyroid, a rare and aggressive tumor, in a 74-year-old woman with a chronic euthyroid goiter. The tumor, which involved most of the glandular surface of the thyroid, showed an infiltrating histological pattern, with epithelioid cells displaying a tendency to form vascular lights. Immunohistochemical analysis (CD31 and factor VIII) confirmed the angiomatous nature of the neoplasm and enabled us to establish the differential diagnosis with other malignant processes that can also affect this anatomical area.

Immunohistochemistry of pulmonary and pleural neoplasia

CONTEXT

The use of immunohistochemical stains has several applications in the evaluation of pulmonary and pleural neoplasms. The number of available immunohistochemical stains is continually expanding and, although these stains are an important diagnostic adjunct, their use is not without limitations and pitfalls.

OBJECTIVE

To review and summarize the primary immunohistochemical applications with regard to the most common pulmonary and pleural neoplasms and discuss newly developed markers and common pitfalls.

DATA SOURCES

Pertinent peer-reviewed literature emphasizing immunohistochemical applications in common lung and pleural tumors, unusual and problematic staining patterns in frequently encountered subtypes/histologic variants, and recently developed immunohistochemical stains of potential promise.

CONCLUSIONS

Immunohistochemical stains provide the greatest aid in establishing the site of origin of adenocarcinomas encountered in the lung and in separating epithelioid mesothelioma from adenocarcinoma. Certain subtypes of pulmonary adenocarcinomas may exhibit unusual staining patterns that may be potentially problematic. Immunohistochemistry has a more limited role in separating small cell carcinoma from non-small cell carcinoma, and extreme caution must be used in the situation of crushed biopsy specimens.

Primary pleural neoplasia: entities other than diffuse malignant mesothelioma

CONTEXT

Overwhelmingly, the most common neoplasm involving the pleura is metastatic carcinoma. In contrast, diffuse malignant mesothelioma occurs relatively rarely; however, it is nonetheless the most common neoplasm primary to the pleura. Metastatic carcinoma and diffuse malignant mesothelioma each have their own prognostic and therapeutic characteristics. Other primary pleural neoplasms occur uncommonly or rarely, with their own prognostic and therapeutic characteristics.

OBJECTIVE

To review primary pleural neoplasms other than diffuse malignant mesothelioma, to better ensure correct diagnosis and optimal assessment of prognosis and treatment.

DATA SOURCES

Literature review and primary material from the authors' institutions.

CONCLUSIONS

A nonexhaustive group of uncommon to rare benign and malignant primary pleural neoplasms--other than diffuse malignant mesothelioma--are presented, of which one must be aware in order to maintain an appropriate index of suspicion to include them in the differential diagnosis of a pleural tumor.

Undifferentiated tumor: true identity by immunohistochemistry

CONTEXT

"Undifferentiated tumor" refers to a heterogeneous group of neoplasms with little or no evidence of differentiation on routine light microscopic morphology.

OBJECTIVE

To identify the true identity of undifferentiated tumors by immunohistochemical analysis.

DATA SOURCES

Review of the pertinent literature and the authors' experience.

CONCLUSIONS

For treatment and prognostic evaluation, it is crucial to delineate whether an undifferentiated neoplasm is epithelial, mesenchymal, melanocytic, or hematopoietic in nature. Application of a screening panel to demonstrate the expression of markers of major lineages is fundamental for determination of the broad category of neoplasia. Because poorly differentiated carcinomas and in particular sarcomatoid carcinomas are known to be heterogeneous in their antigen expression, several epithelial markers in combination may be required to establish the carcinomatous nature of tumor. A diagnostic misinterpretation as a consequence of occasional aberrant or unexpected antigen expression is best avoided by using a broad panel that includes both antibodies that are anticipated to be positive and those that are expected to be negative. In this treatise, the immunohistochemical dissection of undifferentiated tumors on the basis of their morphologic features is outlined, supplemented with algorithmic immunohistochemical analysis for each morphologic category of small round cell tumors, carcinomatous tumors, sarcomatous (or sarcoma-like) tumors, and tumors with histologically overlapping features, including hematolymphoid malignancies, melanoma, and sarcomas with epithelioid appearance. The utility of several organ- or tissue-specific markers in the context of undifferentiated tumors is reviewed.

Epithelioid hemangioendothelioma with multiple organ involvement

Epithelioid hemangioendothelioma is a rare vascular neoplasm of uncertain malignant potential. Various reports document metastatic or concurrent epithelioid hemangioendothelioma in several sites, most commonly with combined lung and liver involvement. The concurrent involvement of multiple sites at presentation may cause diagnostic problems because epithelioid hemangioendothelioma can mimic other neoplastic processes. Although it is a chemo-resistant disease, chemotherapy is usually advised for patients with metastatic or concurrent involvement. Here we document the presentation, treatment, and outcome of two cases with concurrent involvement of the lung and liver.

Primary pleural epithelioid hemangioendothelioma with rhabdoid phenotype: report and review of the literature

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor described in diverse locations including lung and liver. Relative to these sites, primary EHE of the serous cavities is uncommon. EHE in the serous cavities mimics mesothelioma and adenocarcinoma clinically, radiographically, cytologically, and histologically. EHEs have plasmacytoid epithelioid cells with cytoplasmic vacuoles. In addition to these features, we noted eccentric nuclei with abundant eosinophilic cytoplasm and nuclei displaced peripherally by globular cytoplasmic inclusions imparting a "rhabdoid" phenotype. These cells were often seen surrounding a hyaline core. Rhabdoid features are not unique to a single entity, and a comprehensive immunohistochemical panel is essential. We report the occurrence of pleural EHE with rhabdoid features presenting in a pleural effusion, and review the literature of primary serosal EHEs.

My approach to the diagnosis of mesothelial lesions

Mesothelial lesions pose considerable diagnostic challenges not only because benign tumours, reactive proliferations and malignant mesothelioma can mimic one another, but also because the morphological patterns displayed by malignant mesothelioma can simulate a variety of epithelial and non-epithelial malignancies. Immunohistochemical markers can aid in distinguishing epithelioid malignant mesothelioma from metastatic adenocarcinoma, but because no single marker reliably separates all cases, a panel of stains is recommended. Immunohistochemical studies are of more limited value in sarcomatoid malignant mesothelioma, and other features often play an essential role. The separation of reactive mesothelial proliferations from malignant mesothelioma on small biopsy can be quite difficult, as distinguishing features, such as stromal invasion, often cannot be adequately assessed. In adequately sampled lesions, however, the distinction between malignant mesothelioma, benign mesothelial proliferations and other tumours can be achieved in most cases by using a carefully integrated approach that incorporates clinical and radiographic data, immunohistochemical studies and, in selected cases, histochemical and ultrastructural techniques.

Epithelioid angiosarcoma of the lung: a rare late complication of Lucite plombage

Epithelioid angiosarcoma of the lung is a rare late complication of Lucite plombage treatment of pulmonary tuberculosis. We describe the clinical, radiological and pathologic findings of a case of epithelioid angiosarcoma of the lung presenting with persistent haemoptysis who had undergone remote lung collapse therapy with Lucite plombage.

Hemangioendotelioma epitelióide da pleura: Sobrevida de 29 meses

Epithelioid haemangioendothelioma of the pleura is a rare neoplasia with a very poor prognosis due to aggressive involvement of the pleura and incomplete surgical treatment. Histological diagnosis and imagiology is also controversial, related to discrete development of the lesions that later reveal nodules. In 2005 there were 31 cases of vascular tumours described in the pleura. Eleven were epithelioid haemangioendotheliomas. This is another case, a 52 year old woman who suffered a traumatism and died 29 months after the histological diagnosis because CAT revealed discrete pleural involvement and a 2 cm nodule was seen only one month before death.

Increased FDG uptake in pulmonary epitheloid hemangioendothelioma

A 40 year-old female was examined for complaints of left arm pain and restriction of movement in the left upper extremity for 3 months. Chest X-ray showed a mass in the left upper lung and the patient was evaluated with computed tomography that confirmed the significant mass in the left paratracheal region and also showed small nodules in both of the lungs. A whole-body FDG-PET scan was performed for the suspicion of malignancy. FDG-PET indicated high FDG accumulation in the lung lesions mainly in the left paratracheal region. FDG-PET findings were highly suspicious of malignancy so the patient had thoracoscopic biopsy of the lesion. The histological findings and immunohistochemistry tests were consistent with pulmonary epitheloid hemangioendothelioma (PEH). Epitheloid hemangioendothelioma (EH) is a systemic name that represents a rare type of malignant tumor of vascular endothelial origin, which can arise in bone, liver, soft-tissue, or lung. PEH is currently known as the lung form of EH. Consequently, our patient had resection of the left paratracheal mass. This report presents a rare case of histologically confirmed PEH, which showed increased FDG accumulation on FDG-PET study. PEH should be added to the other causes of increased FDG uptake.

Review and update of uncommon primary pleural tumors: a practical approach to diagnosis

OBJECTIVE

We address the current classifications and new changes regarding uncommon primary pleural tumors. Primary pleural tumors are divided according to their behavior and are discussed separately as benign tumors, tumors of low malignant potential, and malignant neoplasms.

DATA SOURCES

Current literature concerning primary pleural neoplasms was collected and reviewed.

STUDY SELECTION

Studies emphasizing clinical, radiological, or pathologic findings of primary pleural neoplasms were obtained.

DATA EXTRACTION

Data deemed helpful to the general surgical pathologist when confronted with an uncommon primary pleural tumor was included in this review.

DATA SYNTHESIS

Tumors are discussed in 3 broad categories: (1) benign, (2) low malignant potential, and (3) malignant. A practical approach to the diagnosis of these neoplasms in surgical pathology specimens is offered. The differential diagnosis, including metastatic pleural neoplasms, is also briefly addressed.

CONCLUSIONS

Uncommon primary pleural neoplasms may mimic each other, as well as mimic metastatic cancers to the pleura and diffuse malignant mesothelioma. Correct diagnosis is important because of different prognosis and treatment implications for the various neoplasms.