Thymomas presenting as pleural tumors. Report of eight cases.

Eight cases of thymomas presenting as pleural-based lesions are presented. The patients are five men and three women between the ages of 38 and 71 years (mean 54.5). Histologically, six tumors showed morphologic features indistinguishable from classical mediastinal thymomas, namely lobulation produced by fibrous bands and a biphasic cell population composed of epithelial cells admixed with small lymphocytes. One case showed prominent spindle cell configuration and marked vascularization resulting in a hemangiopericytomalike appearance; in another case, the epithelial component was associated with cystic structures. The radiographic findings were diffuse pleural thickening with encasement of the lung in four cases; an ill defined mass involving the right diaphragmatic pleura with engulfment of the left lower lobe in one case; diffuse pleural thickening along the mid lateral axillary line in one case; and left-sided pleural masses involving the diaphragmatic and chest wall pleural surfaces in another. In the remaining case, a massive unilateral left pleural effusion obscured the underlying lesion. Clinically, the patients presented with varied symptoms, including shortness of breath, fever, and weight loss. Follow-up information was obtained in four patients. One patient died 1 month after initial diagnosis, but no details of the cause of death were available. Another had metastasis to the groin 1 year after diagnosis. The other two patients were alive and well 2-10 years after the initial diagnosis.

Primary mediastinal tumors: part II. Tumors of the middle and posterior mediastinum.

Lymphoma, mediastinal cysts, and neurogenic neoplasms are the most common primary middle and posterior mediastinal tumors. Lymphoma may involve the anterior, middle and/or posterior mediastinum, frequently as lymphadenopathy or as a discrete mass. Foregut cysts are common congenital mediastinal cysts and frequently arise in the middle mediastinum. Pericardial cysts are rare. Schwannoma and neurofibroma are benign peripheral nerve neoplasms, represent the most common mediastinal neurogenic tumors, and rarely degenerate into malignant tumors of nerve sheath origin. Sympathetic ganglia tumors include benign ganglioneuroma and malignant ganglioneuroblastoma and neuroblastoma. Lateral thoracic meningocele is a rare cause of a posterior mediastinal mass.

Cardiac fibroma: clinicopathologic correlates and surgical treatment.

The clinicopathologic findings of 23 patients with cardiac fibroma are presented. The mean patient age was 13 years, with a range of 1 day to 56 years. The presenting symptoms included heart failure, arrhythmias, sudden death, cyanosis, and chest pain. Some patients had no symptoms, and one patient had Gorlin's syndrome. Echocardiography and magnetic resonance imaging were very sensitive in diagnosis. Nineteen patients underwent tumor resection or biopsy, and four tumors were diagnosed at cardiac transplantation or autopsy on explanted hearts. In five surgical cases, complex operations were necessary, including pericardial or synthetic patches, valve replacement, or coronary artery grafting. Two operative deaths occurred in patients with surgical resections and four operative deaths in patients who at the time of the operation were deemed to have inoperable disease and only biopsy was performed. All deaths but one were in patients younger than 2 years of age. Four patients with subtotal resections did well after the operation. Dense collagen was more frequent in tumors in older patients. We conclude that fibromas are congenital tumors that are frequently discovered in adolescents and adults. Surgical treatment is generally successful, and imaging techniques are helpful in preoperative assessment.

Primary mediastinal tumors. Part 1: tumors of the anterior mediastinum.

Primary anterior mediastinal neoplasms comprise a diverse group of tumors and account for 50% of all mediastinal masses. Thymomas are most common and can be locally invasive and associated with parathymic syndromes. Thymic carcinomas and thymic carcinoids are rare malignancies with a propensity for local invasion and distant metastases. Thymolipomas are benign thymic tumors. The mediastinal germ cell tumors are a heterogeneous group of benign and malignant neoplasms. Mediastinal lymphangiomas are rare tumors and predominantly occur in young children. In contrast, mediastinal goiters are relatively common in adults. Mediastinal parathyroid adenomas are an uncommon cause of persistent hyperparathyroidism and rarely cause a discernible mass. The clinical, radiologic, and therapeutic aspects of the most common masses are reviewed.

Diffuse panbronchiolitis: histologic diagnosis in unsuspected cases involving North American residents of Asian descent.

OBJECTIVE: To study and report two cases of diffuse panbronchiolitis in patients of Asian ancestry residing in the United States and to review the literature pertaining to this disease. DESIGN: Diffuse panbronchiolitis is a progressive interstitial pneumonitis occurring primarily in Japan. Rare cases are now being identified in Europe and North America. Patients often have a history of sinusitis, present with dyspnea on exertion, and show a restrictive pattern on pulmonary function tests. The clinical, radiologic, and pathologic features of two cases of the disease received for consultation at the Armed Forces Institute of Pathology, Washington, DC, are reported with a review of the literature. RESULTS: Chest radiographs revealed bilateral small nodular opacities with ill-defined borders. High-resolution computed tomography demonstrated the abnormalities to have a centrilobular distribution. Histologically, there was transmural chronic inflammation centered on the terminal bronchioles and an interstitial infiltrate of foamy macrophages. CONCLUSION: Diffuse panbronchiolitis may be mistaken for other more common small airway diseases and may be underrecognized in Western nations. The immigration of Asians and sporadic case reports involving non-Asians make recognition of this disease entity important, as the implications for therapy are different than that of other small airway diseases.

Tumors of the trachea.

Tumors of the trachea are rare and create signs and symptoms that mimic common upper airway diseases. A tracheal mass is not usually considered in the clinical differential diagnosis of an affected patient and is often overlooked on chest radiographs. The purpose of this article is to prompt earlier diagnosis and improve long-term survival of patients with a tracheal tumor through the presentation of the salient clinical, pathological, and radiological features of a variety of benign and malignant tracheal diseases.

Tumors of the thymus.

Thymic neoplasms are a common cause of an anterior mediastinal mass and may be benign or malignant. Thymic cysts are congenital or acquired and may be associated with a thymic malignancy. True thymic hyperplasia and thymic lymphoid hyperplasia may enlarge the thymus and simulate a neoplasm. Thymoma and thymic carcinoma are epithelial malignancies with distinct clinicopathologic features. Thymic carcinoid is a rare aggressive neuroendocrine malignancy associated with multiple endocrine neoplasia 1. Thymolipoma is a benign neoplasm. Hodgkin and non-Hodgkin lymphoma may primarily or secondarily involve the thymus. Primary mediastinal germ cell tumors may arise primarily within the thymus and include mature teratoma, seminoma, and non-seminomatous malignant germ cell tumors.

Opportunistic fungal pneumonia.

Opportunistic fungal infection is a common cause of serious morbidity and mortality in immunocompromised patients. These infections occur primarily in patients with chemotherapy-induced neutropenia, acquired immunodeficiency syndrome. or immunosuppression after solid organ or bone marrow transplantation. The most important opportunistic fungal pathogens include Cryptococcus neoformans, Candida and Aspergillus species, and the fungi that cause mucormycosis. Opportunistic pneumonia caused by previously unrecognized pathogens, such as Fusarium, Penicillium, and the dematiaceous fungi, are increasingly reported. The clinical and radiologic features of opportunistic fungal pneumonia are highly variable and often nonspecific. Diagnosis requires knowledge of the various modes of presentation, radiologic manifestations, and epidemiology of these infections. Because many of these organisms can colonize the upper airway, sputum cultures are considered diagnostically unreliable. Instead, definitive diagnosis requires culture of the fungus from infected tissue or demonstration of the organism on microscopic examination.

Congenital cystic adenomatoid malformation.

Congenital cystic adenomatoid malformation of the lung is a rare lesion that typically manifests as neonatal respiratory distress secondary to progressive expansion of the affected lung. Three distinct types have been described based on the size of the cysts and the microscopic appearance. Type I lesions are characterized by large cysts of varying sizes (measuring more than 2 cm in diameter), type II lesions typically contain cysts of a more uniform size (not exceeding 2 cm in diameter), and type III lesions contain microscopic cysts. Radiologic findings include single or multiple large cysts, multiple small cysts of uniform size, and solid-appearing masses. The treatment of choice is excision of the affected lobe. The prognosis is favorable in the absence of pulmonary hypoplasia, fetal hydrops, or associated congenital anomalies.

Fat attenuation lesions of the mediastinum.

The identification of fat within a focal or diffuse mediastinal lesion significantly narrows the differential diagnosis. In many cases, a specific diagnosis can be suggested on the basis of CT findings. In this article, we illustrate and review the characteristic CT features of common and uncommon fat attenuation lesions of the mediastinum, including focal masses and diffuse abnormalities.

Thymolipoma: clinicopathologic review of 33 cases.

The clinical, radiologic, and pathologic features of 33 cases of mediastinal thymolipoma are presented. The patients' ages ranged from 2 to 64 (mean, 33) years; 18 were male and 15 were female. Clinically, the majority of patients (18 cases) were asymptomatic. Five patients presented with upper respiratory symptoms, two patients presented with chest pain, two patients with myasthenia gravis, and one patient with a neck mass; no clinical information was available in four patients. All the tumors were located in the anterior mediastinum and in all cases complete surgical resection of the mass was accomplished. Radiographically, 20 cases showed an anterior mediastinal tumor; when available, computed tomography and/or magnetic resonance imaging demonstrated a mixture of fat and soft tissue elements in these tumors. Grossly, the tumors were described as fairly well-circumscribed, soft, yellowish, fatty tumors with focal solid areas. The tumors varied in size from 4.5 to 36 cm in greatest dimension. Histologically, they were characterized by the presence of abundant mature adipose tissue admixed with areas containing remnants of thymic tissue. The fatty tissue consisted of mature adipocytes devoid of atypia, and the thymic tissue component varied from strands of atrophic thymic epithelium to large areas containing thymic parenchyma showing the typical mixed epithelial/lymphocytic architecture with numerous Hassall's corpuscles. Areas of calcification and cystic degeneration of Hassall's corpuscles were quite prominent in a large number of cases. Our study shows that thymolipomas span the age ranges from the very young to adult individuals with a slight prevalence for patients under the age of 40.(ABSTRACT TRUNCATED AT 250 WORDS)

Thoracic sarcoidosis: radiologic-pathologic correlation.

Sarcoidosis is a systemic disease of unknown etiology with variable presentation, prognosis, and progression. At diagnosis, about 50% of patients are asymptomatic, 25% complain of cough or dyspnea, and 25% have skin lesions (erythema nodosum, lupus pernio, or plaques or scars) or eye symptoms (or develop them during the course of the disease). Bilateral hilar adenopathy is the most common radiographic finding. Other characteristic findings include interstitial lung disease, occasional calcification of affected lymph nodes, and pleural effusions and thickening. Computed tomography is more sensitive than radiography in the detection of adenopathy and subtle parenchymal disease; gallium-67 scintigraphy is useful in identifying extrathoracic sites of involvement, detecting active disease, and assessing response to treatment. The diagnosis is established most securely when clinicoradiologic findings are supported by histologic evidence of widespread noncaseating granulomas. The disease ranges from a self-limited subclinical process to chronic debilitation and death, with the major complications being fibrosis, mycetoma formation, and cor pulmonale. Because the disease so often involves thoracic structures, chest radiography plays a crucial role in the diagnosis, staging, and follow-up of sarcoidosis.

Thymoma: radiologic-pathologic correlation.

Thymoma is the most common primary neoplasm of the thymus. The majority of thymomas are encapsulated masses and exhibit a benign behavior. Less frequently, thymomas may be locally invasive, or rarely they may metastasize to distant sites. The usual clinical presentation is that of an anterior mediastinal mass found incidentally in an asymptomatic patient. The variable gross features of thymoma and the potential for local invasion result in a variety of radiologic appearances. The most common radiologic manifestation is a rounded, soft-tissue mass of the anterior superior mediastinum. Computed tomography and magnetic resonance imaging typically show a prevascular mediastinal mass of variable size and may be helpful in the evaluation of adjacent structures in cases of invasive thymoma. The treatment of choice is complete surgical excision. Radiation therapy and chemotherapy may be used adjunctively to surgery in the treatment of invasive tumors. The prognosis of encapsulated thymoma is generally favorable. Invasive tumors are associated with a worse prognosis but may respond to radical resection.

Pulmonary angiitis and granulomatosis: radiologic-pathologic correlation.

Five distinct clinical syndromes of pulmonary angiitis and granulomatosis are currently recognized: Wegener granulomatosis, lymphomatoid granulomatosis, necrotizing sarcoid granulomatosis, bronchocentric granulomatosis, and allergic angiitis and granulomatosis (Churg-Strauss syndrome). Patients typically present in middle age with fever, cough, hemoptysis, dyspnea, or chest discomfort. Upper airway involvement such as sinusitis suggests Wegener granulomatosis. Medical renal disease is associated with Wegener granulomatosis and Churg-Strauss syndrome. Asthma may be present in bronchocentric granulomatosis and Churg-Strauss syndrome. Pathologic examination of these entities demonstrates vasculitis, granulomatous inflammation, and parenchymal necrosis. The radiologic manifestations of pulmonary disease are varied, but the most typical appearance is that of multiple nodules or masses that may demonstrate cavitation. Diffuse multifocal air-space opacities with or without cavitation may also be seen. Pulmonary hemorrhage is a well-known presenting manifestation of Wegener granulomatosis and, less commonly, of Churg-Strauss syndrome. Because of the multifocal lung involvement in these diseases, pulmonary metastases and infectious causes are often considered in the differential diagnosis. Affected patients are treated with cytotoxic agents and corticosteroids. The prognosis is variable, depending on the specific syndrome, but may be favorable in the absence of significant complications.

Mediastinal mature teratoma: imaging features.

OBJECTIVE: The purpose of this study was to characterize the cross-sectional imaging features of mediastinal mature teratomas. MATERIALS AND METHODS: Sixty-six cases of mediastinal mature teratoma were retrospectively reviewed, noting clinical, radiologic, surgical, and pathologic findings. The patient population consisted of 38 females and 28 males who were 1 week to 67 years old (mean age, 23 years 10 months). RESULTS: Forty-six patients presented with symptoms, predominantly chest pain, dyspnea, and cough. Twenty patients were asymptomatic. Fifty-four tumors were found in the anterior mediastinum, two in the posterior mediastinum, one in the middle mediastinum, and nine in multiple compartments. CT studies (n = 66) showed masses of heterogeneous attenuation with varying combinations of soft tissue, fluid, fat, and calcium. Soft-tissue attenuation was observed in 66 tumors (100%), fluid in 58 tumors (88%), fat in 50 tumors (76%), and calcification in 35 tumors (53%). The most frequent combination of attenuations was soft tissue, fluid, fat, and calcium, which was noted in 26 masses (39%). The combination of soft tissue, fluid, and fat was seen in 16 tumors (24%); and the combination of soft tissue and fluid was seen in 10 tumors (15%). Fat-fluid levels were seen in seven masses (11%). CONCLUSION: Mediastinal mature teratoma typically manifests on CT as a heterogeneous anterior mediastinal mass containing soft-tissue, fluid, fat, or calcium attenuation, or any combination of the four. Fluid-containing cystic areas, fat, and calcification occur frequently. Cystic lesions without fat or calcium were seen in 15% of tumors. Fat-fluid levels, considered highly specific for the diagnosis of mediastinal mature teratoma, are uncommon. CT is the imaging technique of choice in the evaluation of these lesions.

Mediastinal hemangioma: radiographic and CT features in 14 patients.

PURPOSE: To characterize the imaging features of mediastinal hemangioma. MATERIALS AND METHODS: The authors retrospectively reviewed chest radiographs and computed tomographic (CT) scans from 14 patients with mediastinal hemangioma. RESULTS: Most mediastinal hemangiomas manifested as well-marginated masses at CT. Three masses had punctate calcifications, and one had phleboliths. Five masses were of heterogeneous attenuation at unenhanced CT. Ten of 11 (91%) hemangiomas were of heterogeneous attenuation at contrast material-enhanced CT, and the following four patterns were observed: central (n = 6, 60%), mixed central and peripheral (n = 2, 20%), peripheral (n = 1, 10%), and nonspecific (n = 1, 10%) increased attenuation. Central increased attenuation was observed more frequently after administration of a bolus of contrast material than after slow infusion. CONCLUSION: Hemangiomas should be considered in the differential diagnosis of well-marginated mediastinal masses that have heterogeneous attenuation on CT scans, show central enhancement after administration of contrast material or contain punctate calcification.

Thymolipoma: analysis of 27 cases.

PURPOSE: To characterize the radiologic features of thymolipoma. MATERIALS AND METHODS: Twenty-seven cases of thymolipoma were reviewed. Clinical, radiologic, and pathologic findings were noted. RESULTS: The masses occurred in 15 male and 12 female patients (mean age, 26.7 years). All 27 tumors were in the anterior mediastinum; 22 were in the anterior inferior mediastinum. On frontal radiographs, 12 tumors simulated cardiomegaly. On lateral radiographs, 12 tumors draped over the ipsilateral hemidiaphragm, simulating diaphragmatic elevation. Computed tomographic scans (n = 11) demonstrated a mixture of fat and soft-tissue attenuation in 10 tumors corresponding to adipose and thymic elements found at microscopy. Magnetic resonance images (n = 2) demonstrated fat and soft-tissue signal intensity characteristics. Both types of studies showed a connection between tumor and thymus. CONCLUSION: Thymolipomas are anterior mediastinal masses that may conform to the shape of adjacent structures. The diagnosis is supported by imaging studies that demonstrate fat and soft tissue within the tumor.

Bronchogenic carcinoma: radiologic-pathologic correlation.

Bronchogenic carcinoma is the leading cause of death from cancer in men and women in the United States. Although the cause of this malignancy is probably multifactorial, approximately 85% of lung cancer deaths are attributable to cigarette smoking. Patients may present with symptoms of airway obstruction caused by central tumors, symptoms related to direct tumor invasion of surrounding structures, or symptoms produced by distant metastases. There are four major cell types: adenocarcinoma, squamous cell carcinoma, undifferentiated large cell carcinoma, and small cell carcinoma. Adenocarcinoma and undifferentiated large cell carcinoma are generally peripheral lesions manifesting as solitary nodules or masses, whereas squamous cell carcinoma and small cell carcinoma are typically central and may manifest as hilar masses, atelectasis, or pneumonia. The prognosis for patients with bronchogenic carcinoma is poor, with an overall 5-year survival of 10%-15%. In general, patients with squamous cell carcinoma have the best prognosis, those with adenocarcinoma and undifferentiated large cell carcinoma have an intermediate prognosis, and those with small cell carcinoma have the worst prognosis.