Angiosarcoma of the lung: 2 cases report and literature reviewed

Primary Pulmonary Angiosarcoma Found Incidentally in a Complicated Patient: A Rare Case Report

INTRODUCTION

Primary pulmonary angiosarcoma (PPA) is a highly aggressive and rare malignancy originating from the endothelial cells of blood vessels in the lungs. PPA is an extremely rare subtype, with less than 30 cases reported to date. PPA is not only challenging to diagnose but also has a poor prognosis, often resulting in a high mortality rate within a year of diagnosis, regardless of the treatment approach.

METHOD

We present the case of a 33-year-old woman with no significant past medical history who presented with abdominal pain and was incidentally found to have a right hilar mass with pleural effusion and empyema. After undergoing surgery for a perforated gastric ulcer, her pulmonary lesions were further worked up. Despite an extensive diagnostic evaluation, including imaging, bronchoscopy, and thoracotomy, establishing a diagnosis was challenging. Ultimately, PPA was diagnosed on surgical lung biopsy, and the patient was started on pazopanib and paclitaxel chemotherapy but expired after 1 month due to multiple complications.

CONCLUSION

This case highlights the difficulty in diagnosing this rare tumor and its poor prognosis regardless of therapy. Greater awareness of PPA and more research are needed to improve early detection and treatment options for this deadly disease.

[Severe hemoptysis in the onco-hematology patient]

In France, even though it occurs only exceptionally in cases of hemopathy, severe hemoptysis in cancer is the leading cause of hemoptysis. Without adequate treatment, in-hospital mortality exceeds 60%, even reaching 100% at 6 months. The management of severe hemoptysis should be discussed with the oncologist. Aside from situations of threatening hemoptysis, in which bronchoscopy should be performed immediately, CT angiography is an essential means of localizing the bleeding and determining the causes and the vascular mechanisms involved. In more than 90% of cases, hemoptysis is linked to systemic bronchial or non-bronchial hypervascularization, whereas in fewer than 5%, it is associated with pulmonary arterial origin or, exceptionally, with damage to the alveolar-capillary barrier. The most severely ill patients must be treated in intensive care in centers equipped with interventional radiology, thoracic surgery and, ideally, with interventional bronchoscopy. Interventional radiology is the first-line symptomatic treatment. In over 80% of cases, bronchial arteriography with embolization allows immediate control. Emergency surgery should be avoided, as it is associated with significant mortality. Appropriate and adequate care reduces hospital mortality to 30%, enabling patients to benefit from the most recent, survival-prolonging treatments.

Primary pulmonary angiosarcoma mimicking diffuse pulmonary hemorrhage: A case report

Pulmonary angiosarcomas are usually secondary tumors, and a primary angiosarcoma of the lung is extremely rare. The present study reports a case of an elderly patient diagnosed with primary pulmonary angiosarcoma (PPA). A 78-year-old man presented with a 3-month history of cough and blood in phlegm. A computed tomography scan of the chest indicated pulmonary infection with ground-glass opacity in the right upper lobe. The patient underwent lobectomy of the right upper lobe as his clinical symptoms did not significantly improve after anti-infection treatment. The postoperative pathological examination confirmed a diagnosis of PPA. He developed left lung and pelvic metastases 1 month after surgery. After four cycles of liposomal doxorubicin therapy, the patient achieved partial remission. The patient remained in sustained remission after 6 months of follow-up. The present case report is intended to provide diagnostic insight into PPA. In addition, the findings indicate that timely diagnosis and treatment of PPA are very important due to its increased risk of local recurrence and distant metastasis.

Pulmonary Angiosarcoma With Synchronous Invasive Aspergillosis Presenting as Diffuse Alveolar Hemorrhage and Acute Kidney Injury: A Case Report of a Previously Unreported Combination Posing a Diagnostic Challenge

Angiosarcoma is a rare soft tissue sarcoma originating from endothelial cells. It can occur anywhere when there is a blood vessel or lymphatic channel, making highly perfused cutaneous sites their usual location, though they can also develop within visceral structures. Pulmonary angiosarcoma is usually caused by metastasis from other primary sites. The clinical course of pulmonary angiosarcoma is very aggressive, and the prognosis is poor. We present a case of a 55-year-old man who presented to the hospital with progressive exertional dyspnea and right-sided pleuritic chest pain for the past few days. He was found to have recurrent anemia and acute kidney injury. His hospital course was complicated by the development of hypoxia and hemoptysis. Computed tomography of the chest without contrast revealed bilateral nodular, ground-glass opacities compatible with diffuse alveolar hemorrhage. Further investigation with a lung biopsy revealed epithelioid angiosarcoma with extensive microvascular tumor emboli and invasive pulmonary aspergillosis (Aspergillus fumigatus) with patchy necrotizing pneumonia. He later developed acute hypoxic respiratory failure and worsening kidney failure, so he was transferred to the intensive care unit. Upon discussing with the family, the patient was put on comfort measures, and he passed away the following day. We present a rare presentation of concurrence of pulmonary angiosarcoma and invasive aspergillosis. Upon searching the literature, our case is one of the first to report such concurrence. Because of its rarity, the non-specific clinical presentation makes the diagnosis challenging.

Primary pulmonary epithelioid angiosarcoma with thyroid tumor history: A case report and literature review

Primary pulmonary epithelioid angiosarcoma is a rare tumor type without any specific clinical and imaging features. Therefore, it is associated with high rates of misdiagnosis. The present study reports the case of a 54-year-old female patient who was admitted after complaining of cough, expectoration and bloody sputum for >5 months in May 2021. The patient reported a previous history of papillary thyroid carcinoma in 2003 and had undergone treatment through surgery, postoperative chemotherapy and iodine131 therapy. Chest computed tomography (CT) was performed in May 2021, which indicated that the disease had progressed rapidly since February 2021. CT-guided lung biopsy and immunohistochemical staining of the tumor indicated positivity for CD31, CD34 and E26 transformation-specific-related gene markers. The tumor was negative for thyroid cancer-associated antibodies; thus, a diagnosis of primary pulmonary epithelioid angiosarcoma was made. The patient died 3 months after the diagnosis. Primary pulmonary epithelioid angiosarcoma is a rare tumor type with high recurrence and metastasis rates. This tumor has no specific clinical symptoms and signs and is thus easily misdiagnosed. Biopsy is essential for diagnosis of the disease, particularly if patients have a tumor history.

Case Report: Primary Pulmonary Angiosarcoma With Brain Metastasis

Primary pulmonary angiosarcoma (PPA) is a rare malignant vascular tumor, of which early diagnosis is challenging due to lack of specific clinical manifestations and a low level of suspicion. Here, we report a case of PPA presented with advanced brain metastasis. A 21-year-old patient with 1 week history of headache and mild cough was hospitalized for a head injury. Head MRI showed multiple intracranial lesions with brain edema. Chest CT displayed bilateral pulmonary infiltrates with mediastinal lymph node enlargement. After 2 months of anti-tuberculosis treatment, the patient was readmitted for persistent headache and cough with occasional hemosputum along with worsening pulmonary and intracranial lesions. Despite seizure prophylaxis and control of intracranial pressure and brain edema, his symptoms progressively aggravated, accompanied by cough with bloody sputum, frequent epileptic seizures, and hypotension. He eventually developed coma and died within 3 months of onset of symptoms. An autopsy confirmed PPA with brain metastasis.

Primary pulmonary angiosarcoma presenting as Pancoast tumor

A primary pulmonary angiosarcoma is an extremely rare entity with fewer than 30 cases reported in the literature. We found no reports of primary pulmonary angiosarcoma presenting as a Pancoast tumor. We describe a case of pulmonary angiosarcoma located in the right superior sulcus that was treated by surgery.

ALDH Expression in Angiosarcoma of the Lung: A Potential Marker of Aggressiveness?

Background: Primary angiosarcoma of the lung is a very aggressive rare malignant disease resulting in a severe prognosis (1). This type of cancer represents about 2% of all soft tissue sarcomas and has a high rate of metastasis through the hematogenous route. For the rarity of this malignant vascular tumor it is still challenging to set a diagnosis (1). The diagnostic features that have thus far been considered include primarily clinical and radiological findings. In some cases, immunohistochemical characteristics based on the most common markers used in pathology have been described. The aim of this report is to present two cases of angiosarcoma of the lung in which the aldehyde dehydrogenase (ALDH) marker was analyzed by immunohistochemistry.

Methods: We report two cases of angiosarcoma of the lung in patients underwent lung surgery at our Unit. In addition to the standard histopathological analysis for this disease, immunohistochemistry using an ALDH1A1 antibody was performed in both of the cases. For ALDH quantification, a semi-quantitative method based on the positivity of the tumor cells was used: 0 (<5%), 1 (5–25%), 2 (>25–50%), 3 (>50–75%), 4 (>75%).

Results: One patient with recurrent lung disease survived, achieving complete remission after chemo- and radiotherapy. The second patient died of recurrent disease within 5 years of diagnosis. ALDH1A1 was evaluated in both of these cases using an immunohistochemistry scoring system based on the positivity for this marker. The scores were consistent with the patients' clinical outcomes, as the lower (score 1) was observed in the patient with the better clinical outcome, while the higher (score 3) was seen in the patient with the worse outcome.

Conclusion: Our data suggest that ALDH may be an important clinical marker in angiosarcoma of the lung. Although further studies need to be performed in a larger cohort of patients, we believe that, if the results will be confirmed, ALDH1A1 may be used to stratify patients in terms of prognosis and for targeted therapy.

Hémorragies intra-alvéolaires

L’hémorragie intra-alvéolaire (HIA), maladie rare, est une urgence thérapeutique, car elle peut conduire rapidement vers une insuffisance respiratoire aiguë asphyxiante avec décès. La triade, hémoptysie–anémie–infiltrat radiologique, suggère le diagnostic d’HIA, mais elle peut manquer dans deux tiers des cas, y compris chez des patients en détresse respiratoire. La tomodensitométrie thoracique peut aider dans les formes atypiques. Le diagnostic d’HIA repose sur la réalisation d’un lavage bronchoalvéolaire. Les étiologies en sont très nombreuses. Il importera de séparer, en urgence, les HIA d’origine non immune, avec un dépistage de celles d’origine septique qui doivent bénéficier d’une enquête microbiologique ciblée et cardiovasculaire avec la réalisation d’une échographie cardiaque, des HIA immunes (les vascularites liées aux anticorps anticytoplasme des polynucléaires neutrophiles, les connectivites et le syndrome de Goodpasture), avec la recherche d’autoanticorps et la réalisation de biopsies au niveau des organes facilement accessibles. La biopsie pulmonaire doit rester exceptionnelle. En cas d’HIA immune inaugurale, un traitement par stéroïdes et cyclophosphamide peut être débuté. Les indications du rituximab commencent à être mieux établies. Le bénéfice des échanges plasmatiques est débattu. En cas de réapparition d’infiltrats pulmonaires, chez un patient suivi pour une HIA immune, on s’efforcera d’écarter une infection dans un premier temps.

Clinical and diagnostic features of angiosarcoma with pulmonary metastases: A retrospective observational study

Angiosarcoma with pulmonary metastasis is a rare, fatal disease that often presents with multiple pulmonary nodules and diffuse alveolar hemorrhage. We herein review the detailed clinical characteristics of pulmonary metastatic angiosarcoma and determine a reasonable diagnostic strategy.The medical records of 11 patients with pulmonary angiosarcoma were reviewed.The mean age of the patients was 45.7 years (range, 30-71 years). All patients were male. The most common symptom was hemoptysis (8/11). Common initial misdiagnoses were tuberculosis (5/11), vasculitis (2/11), nontuberculous infectious disease (1/11), and constrictive pericarditis (1/11). Chest computed tomography (CT) of patients with hemoptysis showed bilateral, randomly distributed, variably shaped, and differently sized nodules, as well as ground-glass opacities (GGO) (8/11). The right heart was the most common primary tumor site (8/11), but the sensitivity of echocardiography was limited; CT angiography and cardiac magnetic resonance imaging (MRI) revealed more atrial masses. CT-guided needle biopsy was difficult to perform in most patients because of the small size of the nodules. The diagnosis was made by surgical biopsy of either the lung (3/9) or heart (6/9). The median overall survival of patients who underwent lung biopsy and those who underwent cardiac/pericardiac biopsy was 4.1 and 1.4 months, respectively (P = .098). The median overall survival of the 9 available patients was 5.0 months (95% confidence interval, 0.500-8.544).Angiosarcoma with pulmonary metastases should be considered in patients with hemoptysis and concurrent GGO and nodules on their chest CT scan. Careful cardiologic monitoring is necessary for these patients, even without any cardiac symptoms or signs, and enhanced cardiac MRI is the first recommendation. Surgical biopsy is reliable for histological diagnosis, but the safety of the lung biopsy should be carefully assessed. When primary cardiac tumors are identified, heart biopsy should be preferentially considered.

Angiosarcoma of the lung

Angiosarcoma is a rare malignant vascular tumor. Pulmonary involvement is usually attributable to metastasis from other primary sites, primary pulmonary angiosarcoma therefore being quite uncommon. We report a case of angiosarcoma with pulmonary involvement, probably primary to the lung, which had gone untreated for more than two years. We describe this rare neoplasm and its growth, as well as the extensive local invasion and hematogenous metastasis at presentation. We also discuss its poor prognosis.

Angiosarcoma in the chest: radiologic-pathologic correlation: Case report

RATIONALE

Angiosarcomas are rare, malignant vascular tumors.

PATIENT CONCERNS

They represents about 2% of all soft tissue sarcoma, which can often metastasize through the hematogenous route. The radiological features have been analyzed in 4 patients with metastatic angiosarcoma in the chest.

DIAGNOSES

The main radiologic findings included nodules, cysts, nodules with halo sign, and vascular tree-in-bud. Morphologic features, as observed in the histologic specimen, have been correlated with radiologic appearance.

LESSONS

Metastatic angiosarcomas to the lung are characterized by a wide variety of radiologic appearances that can be very characteristic. Computed tomographic findings observed include bilateral solid nodules, cystic, and bullous lesions sometimes associated with spontaneous hemopneumothoraces.

Primary Pulmonary Angiosarcoma Presenting with Hemoptysis and Ground-Glass Opacity: A Case Report and Literature Review

Angiosarcoma originates from the vascular endothelium and accounts for only 1-2% of all sarcomatous malignancies. The skin is one of the most common primary sites. However, primary pulmonary angiosarcoma is rare, and only 31 cases of primary pulmonary angiosarcoma have been reported. A 79-year-old Japanese female developed bloody sputum, and chest X-ray and chest computed tomography (CT) showed consolidation with ground-glass opacity (GGO) on the right middle and lower lung fields. The bronchoscopic findings demonstrated bleeding from the right B(4) and B(5), and bronchial arterial embolization was subsequently performed. However, the CT findings demonstrated new pulmonary nodules with GGO in the left lung, and she presented with hemosputum and a progression of anemia. Right hemothorax also occurred, and surgical lung resection was performed to control the bleeding. The pathological analysis of the resected lung revealed the focal growth of atypical alveolar epithelioid-like cells that were positive for CD31 and negative for epithelial membrane antigen, and these atypical cells were replacing the endothelium of the pulmonary artery. Based on these findings, the patient was diagnosed with pulmonary angiosarcoma, which might originate from the endothelium of the pulmonary artery. No abnormal findings were observed except for the pulmonary involvement on systemic CT scanning. However, the patient passed away due to respiratory failure with compression of the brainstem caused by brain metastasis three months after the first visit. Early surgical resection is the important treatment for patients with angiosarcoma. In addition, we review the literature reporting the patients with primary pulmonary angiosarcoma.

Primary pulmonary angiosarcoma: Three case reports and literature review

Primary pulmonary angiosarcoma is a rare type of malignant vascular tumor with a very aggressive clinical course and a grim prognosis. To date, only a handful of cases have been reported in English literature. Its rarity and consequent low index of suspicion makes clinical diagnosis difficult. In this report we present three cases of primary pulmonary angiosarcoma with cough, hemoptysis, and progressive dyspnea to contribute to the sparse literature on this disease. A review is made of previous reports of primary pulmonary angiosarcomas, and the clinical characteristics, diagnosed method, treatment options, and prognosis of pulmonary angiosarcoma are also discussed.

New Insights into Mechanisms and Functions of Nuclear Size Regulation

Nuclear size is generally maintained within a defined range in a given cell type. Changes in cell size that occur during cell growth, development, and differentiation are accompanied by dynamic nuclear size adjustments in order to establish appropriate nuclear-to-cytoplasmic volume relationships. It has long been recognized that aberrations in nuclear size are associated with certain disease states, most notably cancer. Nuclear size and morphology must impact nuclear and cellular functions. Understanding these functional implications requires an understanding of the mechanisms that control nuclear size. In this review, we first provide a general overview of the diverse cellular structures and activities that contribute to nuclear size control, including structural components of the nucleus, effects of DNA amount and chromatin compaction, signaling, and transport pathways that impinge on the nucleus, extranuclear structures, and cell cycle state. We then detail some of the key mechanistic findings about nuclear size regulation that have been gleaned from a variety of model organisms. Lastly, we review studies that have implicated nuclear size in the regulation of cell and nuclear function and speculate on the potential functional significance of nuclear size in chromatin organization, gene expression, nuclear mechanics, and disease. With many fundamental cell biological questions remaining to be answered, the field of nuclear size regulation is still wide open.

Pulmonary metastases from angiosarcoma: a spectrum of CT findings

BACKGROUND

Though a few reports have summarized the computed tomography (CT) findings of pulmonary metastases from angiosarcoma, the detailed CT findings of cysts are not well known, except for their characteristic thin walls.

PURPOSE

To retrospectively summarize the CT findings of pulmonary metastases from angiosarcoma, focusing mainly on the CT findings of cysts.

MATERIAL AND METHODS

Thirty-three patients with pulmonary metastases from angiosarcoma were selected retrospectively. Two radiologists reviewed and assessed patients' chest CT images on a consensus basis for nodules, cysts, the CT halo sign, pneumothorax, pleural effusion, and enlarged lymph nodes. Cysts were also evaluated by wall thickness and smoothness, air-fluid levels, and vessels or bronchi penetrating the cysts. The relationship between cysts and pneumothorax was assessed using the Chi-square test.

RESULTS

Nodules were found in 28 (85%) patients. Cysts were found in 19 (58%) patients; 17 had thin and smooth walls, 10 had thin and irregular walls, and four had thick and irregular walls. In addition, 12 patients showed vessels or bronchi penetrating the cysts, and six showed air-fluid levels. The CT halo sign, pneumothorax, pleural effusion, and mediastinal lymphadenopathy were seen in 19 (58%), 16 (48%), 26 (78.8%), and five (15.2%) patients, respectively. Pneumothorax occurred significantly more frequently in patients with cysts (P = 0.002).

CONCLUSION

Cysts showed variability in their walls, and air-fluid levels and vessels or bronchi penetrating the cysts appeared to be characteristic findings, which may be useful for detection and accurate diagnosis in patients with pulmonary metastases from angiosarcoma.

Primary Thyroid Angiosarcoma with Tracheal Invasion

A 48-year-old woman was referred to our clinic because she had been experiencing hemoptysis for 1 month. Chest computed tomography revealed a small portion of a thyroid mass was penetrating the trachea. Bronchoscopy revealed a blood vessel covered mass located in her trachea. The presence of a malignant tumor was confirmed by a biopsy. The patient was referred to the otolaryngology department for tumor resection and a pathological evaluation identified the thyroid angiosarcoma with tracheal invasion. Angiosarcomas have a poor prognosis, but the patient has not experienced any recurrence two years after surgery. A very rare case of primary thyroid angiosarcoma with tracheal invasion was cured successfully.

Primary Pulmonary Low-Grade Angiosarcoma Characterized by Mismatch between ¹⁸F-FDG PET and Dynamic Contrast-Enhanced CT

We report a rare case of primary pulmonary low-grade angiosarcoma on dynamic contrast-enhanced CT and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT imaging. A 38-year-old, asymptomatic woman was hospitalized because of an abnormality on chest radiography. A dynamic contrast-enhanced chest CT showed a 1.2 cm-sized irregular-margined nodule with strong and persistent enhancement in the right lower lobe. The lesion had low metabolic activity on an ¹⁸F-FDG PET/CT scan. The patient underwent a wedge resection for the lesion, and pathology revealed a primary pulmonary low-grade angiosarcoma.

Primary pulmonary angiosarcoma: A case report

Primary sarcoma is uncommon in the lung, and primary angiosarcoma is exceedingly rare. We report a case of primary pulmonary angiosarcoma of the left lung with emphasis on its growth pattern in the lung. A 48-year-old Japanese man was admitted to our hospital because of dyspnea on exertion. He was subsequently found to have left pleural effusion. Computed tomography shows a nodular lesion measuring 7 × 4 cm in his left lung. Obstruction of the left inferior lobar bronchus was observed, and endobronchial biopsy suggested angiosarcoma. Left pneumonectomy was performed. On macroscopic examination of the cut surface, multiple nodular lesions were observed particularly in portions around branches of pulmonary artery along bronchioles. Histological examination revealed vascular channel-like structure with vague lumen formations by atypical polygonal or spindle-shaped neoplastic cells. Immunohistochemically, the neoplastic cells are positive for FLI-1, ERG, CD31 and von Willebrand factor/factor VIII-related antigen, but not CD34. Angiosarcoma is a particularly rare form of primary pulmonary tumors, and this case report describes its unique macroscopic growth pattern in the lung.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in the detection of primary pulmonary angiosarcomas

Angiosarcoma is a malignant vascular tumor that originates from the mesenchymal cells which have undergone angioblastic differentiation. Pulmonary angiosarcomas are invariably (>90%) metastatic tumors form primaries of the skin, bone, liver, breast, or heart. Primary pulmonary angiosarcomas are exceedingly rare, with just about 20 cases being reported in the literature. We report an additional case with a brief review of the literature of a primary pulmonary angiosarcoma in a 26-year-old lady who presented with intractable hemoptysis. In addition, we highlight the potential of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography as an important diagnostic tool in the evaluation of this tumor and thus contribute to the existing sparse literature on this fascinating yet devastating disease.

A rare case of primary pulmonary epithelioid angiosarcoma detected by (18)F-FDG PET/CT

We describe a rare case of primary pulmonary epithelioid angiosarcoma detected by F-FDG PET/CT. A 54-year-old female patient with history of non-Hodgkin lymphoma underwent F-FDG PET/CT for follow-up. PET/CT detected an area of increased F-FDG uptake corresponding to a 4-cm mass located in the inferior lobe of the left lung. Based on this PET/CT finding, the patient underwent left inferior pulmonary lobectomy. Histology demonstrated the presence of a pulmonary epithelioid angiosarcoma. Other sites of disease were excluded. In our case, F-FDG PET/CT has been useful in detecting and staging this rare primary pulmonary tumor.

A rare cause of hemoptysis

Angiosarcomas are rare, malignant, endothelial-cell tumors of vascular origin that can arise at any body site. They frequently metastasize to the lung, heralded by dyspnea, hemoptysis, chest pain, pneumothoraces, and diffuse pulmonary hemorrhage. However, in most cases lung metastases are discovered after the diagnosis of a primary angiosarcoma has already been established. Very rarely will an undiagnosed metastatic angiosarcoma present as diffuse pulmonary hemorrhage. We describe the case of a 59-year-old male who presented to hospital with dyspnea and hemoptysis. CT chest revealed rapidly progressing nodular changes and broncho-alveolar lavage returns were progressively bloody. Open lung wedge biopsy ultimately revealed metastatic angiosarcoma and extensive pulmonary hemorrhage. Our case highlights the key clinical, radiological, and pathological features of this rare malignancy that frequently metastasizes to the lung and reminds clinicians to consider it as a cause of hemoptysis and pulmonary hemorrhage.

Mechanisms of nuclear size regulation in model systems and cancer

Changes in nuclear size have long been used by cytopathologists as an important parameter to diagnose, stage, and prognose many cancers. Mechanisms underlying these changes and functional links between nuclear size and malignancy are largely unknown. Understanding mechanisms of nuclear size regulation and the physiological significance of proper nuclear size control will inform the interplay between altered nuclear size and oncogenesis. In this chapter we review what is known about molecular mechanisms of nuclear size control based on research in model experimental systems including yeast, Xenopus, Tetrahymena, Drosophila, plants, mice, and mammalian cell culture. We discuss how nuclear size is influenced by DNA ploidy, nuclear structural components, cytoplasmic factors and nucleocytoplasmic transport, the cytoskeleton, and the extracellular matrix. Based on these mechanistic insights, we speculate about how nuclear size might impact cell physiology and whether altered nuclear size could contribute to cancer development and progression. We end with some outstanding questions about mechanisms and functions of nuclear size regulation.

A case of primary angiosarcoma of the lung presenting as a hemorrhagic bronchial tumor

Pulmonary angiosarcomas are usually secondary tumors, and only a few primary cases have been reported. Effective strategies for treating this tumor have not been established, and the prognosis of affected individuals is generally very poor. We report a case of primary angiosarcoma presenting as a hemorrhagic solitary nodule at the bifurcation of the left main bronchus, followed for two years before surgery. Bronchial arteriography revealed a tumor stain sign, and racemose hemangioma of the bronchial artery was excluded. The hemoptysis was not controlled by repeated bronchial artery embolization, and the patient underwent left pneumonectomy with routine mediastinal lymph node dissection. Histopathologically, the excised tissue revealed a highly-cellular growth of atypical spindle cells with a storiform pattern. These atypical cells showed relatively low mitotic activity; the MIB-1 index was 10%. The tumor was diagnosed as a primary angiosarcoma of the lung by the following immunohistological findings: positivity for factor VIII-related antigen and CD31. One year after resection, the patient remains well without signs of recurrence.