Mediastinal tumors and cysts in the pediatric patient

Mediastinal lesions across the age spectrum: a clinicopathological comparison between pediatric and adult patients

The objective of this study was to identify the differences in histopathological distribution and clinical features of mediastinal lesions (MLs) across the age spectrum in Chinese series of patients and to compare with the available literature. A total of 409 cases of MLs, including 137 pediatric and 272 adult patients from a single institution, was reviewed and categorized into groups according to age. Among the 409 cases, the age showed a bimodal distribution with an increased incidence of MLs among (< 10 year) and (60–< 70 year) age groups. Thymic lesions, neurogenic tumors, and cysts made up 57% of MLs among the 409 cases. A significantly higher frequency was found for neurogenic tumors, germ cell tumors, mesenchymal tumors, and lymphatic lesions, (p < 0.01) for all, in pediatric population compared to adults. On the contrary, frequencies of thymic lesions and metastatic carcinomas were significantly higher in adults compared to pediatric category, (p < 0.01) for both. Overall, 41.6% were asymptomatic, however, pediatric patients showed a significantly higher incidence of cough and fever, (p < 0.01) for both, and dyspnea (p = 0.02), than adults. Whereas adult subset showed a significantly higher incidence of chest pain (p = 0.02), or oppression (p < 0.01), than pediatric counterpart. In conclusion, the age spectrum was the factor that influenced the histopathological distribution and the clinical presentation of MLs in Chinese series of patients. Such differences might be considered in the differential diagnosis and therapeutic approach for adult as well as pediatric patients with MLs. Furthermore, our study was comparable to the literature in terms of MLs frequencies.

Clinical spectrum of primary mediastinal tumors: a comparison of adult and pediatric populations at a single Japanese institution

BACKGROUND AND OBJECTIVES

The purpose of this study was to review our Japanese institutional experience of mediastinal tumors and to compare differences in the clinical spectrum between adults and children.

METHODS

We retrospectively reviewed the records of 806 patients (676 adults and 130 children) between 1951 and 2000 at our institution.

RESULTS

There were 244 thymomas (36%), 106 germ cell tumors (16%), 95 congenital cysts (14%), 82 lymphomas (12%), 76 neurogenic tumors (11%), and 24 thyroid tumors (4%) in adult patients. There were 60 neurogenic tumors (46%), 24 germ cell tumor (19%), 17 lymphoma (13%), 10 congenital cysts (8%), and 5 thymomas (4%) in the pediatric patients. There was a significant higher incidence of neurogenic tumors and a lower incidence of thymomas and thyroid tumors in children than adults. The most common location was the anterior compartment (68%) in adults and the posterior compartment in children (52%). The prevalence of malignancy in pediatric patients was lower than adults (37% vs. 47%; P < 0.05). Symptoms due to compression or direct invasion into adjacent structures may have caused the higher incidence of dyspnea or respiratory distress in the pediatric group compared to the adults (15.4% vs. 4.0%; P < 0.001). There were fewer incidences of facial edema in children compared to adults (2.6% vs. 10.7%; P < 0.02). Emergent operations were required more often in the pediatric group than the adult group.

CONCLUSIONS

We demonstrated definite differences in histologic distribution, location, and symptomatology in mediastinal tumors between adult and pediatric populations, which should be considered in the evaluation and planning of a therapeutic modality for mediastinal tumors.

Solid alveolar rhabdomyosarcoma of the thorax in a child

AIMS

This case illustrates the difficulties and pitfalls of diagnosis of alveolar rhabdomyosarcoma in its solid variant and in an unusual primary location, the mediastinum.

CASE DETAILS

A 9-year-old boy presented with a primary thoracic tumour associated with metastasis in the left sacroiliac joint. Bronchial and mediastinal biopsies showed a malignant neoplasm with a solid sheet-like pattern of small round cells with a high nuclear to cytoplasmic ratio associated with little or no fibrosis usually evocative of a peripheral neuroectodermal tumour (PNET) at this age. Immunohistochemical positive staining with vimentin (80% of tumour cells), desmin (20%) and titin (30%) antibodies was suggestive of a rhabdomyosarcoma. In addition, all neural cell adhesion molecule (NCAM) markers tested were positive as well as MIC2, a marker for the Ewing family of sarcomas. There was no rhabdomyoid differentiation at ultrastructural examination. Molecular analysis with RT-PCR amplification of RNA isolated from the tumour demonstrated the presence of a PAX3/FKHR fusion transcript, product of a t(2;13) reciprocal translocation, a genetic marker specific for alveolar rhabdomyosarcoma.

CONCLUSIONS

The diagnostic methodology of a small round cell tumour of the child must now include immunohistochemical study and molecular biology to confirm the diagnosis of alveolar rhabdomyosarcoma, in a solid and undifferentiated variant.

A review of open biopsy for mediastinal masses

OBJECTIVE

To review the recent experience with biopsied mediastinal lesions in children and to assess the impact of recent advances in imaging and surgical techniques on diagnosis.

METHODOLOGY

The clinical and radiological features of 55 patients who had mediastinal biopsies at The Royal Alexandra Hospital For Children (RAHC) over 15 years were reviewed.

RESULTS

Fifty-five patients presented to RAHC between 1978 and 1993 with lesions of the mediastinum requiring biopsy of that site. Thirty-one of the 55 (56%) lesions were malignant. Neurogenic tumours were the most common (40%). In order of frequency the following lesions were found: neuroblastoma (15), teratoma (eight), non-Hodgkin's lymphoma (NHL; eight), enteric cyst/duplication (five), ganglioneuroma (five), bronchogenic cyst (three), ganglioneuroblastoma (two), lymphangioma (two), abscess (two), Hodgkin's lymphoma (HL; two), oesophageal granuloma (one), Langerhan's cell histiocytosis (one), congenital fibromatosis (one). Eighty-two per cent of neurogenic tumours were located in the posterior mediastinum, while 75% of teratomas and 100% lymphoid tumours were located anteriorly. Symptoms were generally unhelpful in establishing a specific diagnosis and in 27% of cases the lesions were discovered incidentally. Physical signs, such as thoracic inlet obstruction and neurological findings, were helpful clinically in localizing lesions within the mediastinum. Chest radiography enabled lesions to be subdivided within the mediastinum. This localization, in combination with the age at presentation, predicted the tissue diagnosis. Computerized tomography (CT) and magnetic resonance imaging (MRI) further defined the lesion and demonstrated involvement of adjacent structures. Histology, however, was essential to distinguish benign from malignant lesions.

CONCLUSIONS

The clinical presentation of mediastinal masses is often non-specific or incidental. Despite recent advances in imaging technology and biopsy techniques, full histological examination is required to exclude malignancy.

Mediastinal teratomas: review of 15 pediatric cases

One hundred fifty-three children with a teratoma presented to one hospital between 1970 and March 1992. The clinical and pathological features of 15 patients with mediastinal teratomas are reviewed; six were newborn and nine aged from infancy to 13 years. Thirteen patients including the six newborns presented with respiratory distress and all 15 patients had a mass on chest radiograph. A definite diagnosis of teratoma was not made preoperatively in any of these patients. At operation, a median sternotomy was used to approach seven anterior tumors and a lateral thoracotomy performed in the other eight patients. Histologically two were mature, 10 had immature elements, and three were malignant teratomas. The patients with malignant tumors were all over 12 years of age and died within 6 months of treatment. All six neonates had immature teratomas. Raised serum alpha-fetoprotein levels provided useful markers in two patients with recurrent tumors. Three conclusions can be drawn: (1) mediastinal teratomas are rare in children and frequently are not diagnosed before operation; (2) in newborns these tumors may be immature and present with respiratory distress; and (3) a median sternotomy gives excellent exposure for anterior mediastinal tumors.

Posterior mediastinal masses

Solid mediastinal masses in infancy and childhood occur most frequently in the posterior mediastinum. From 1972 to 1989, 63 patients presented with a posterior mediastinal mass. The median age at diagnosis was 6 years (range, 1 day to 26 years). Thirty patients were female. Forty-five percent of the patients presented with respiratory symptoms or chest pain; 13% had neurologic symptoms, one half of which were related to spinal cord compression; and 5% had a palpable mass. In 32% of patients the mass was an incidental finding. The tumors were of neurogenic origin in 89% of patients, of which neuroblastoma was the most common. Of all patients with posterior mediastinal masses, 60% had malignant tumors. Median follow-up for 62 of 63 evaluable patients was 45 months (range, 1 to 289 months). One patient was lost to follow-up. Of the 62 patients followed, 84% are alive and free of disease. All but 4 of the 32 patients with neuroblastoma are alive and free of disease with a median follow-up of 73 months (range, 7 to 289 months). Patients with neuroblastoma who were diagnosed in the first year of life had a significantly better survival pattern than those presenting after the first year. There were seven deaths in the series: four from neuroblastoma, two from primitive neuroectodermal tumor, and one from malignant schwannoma. Preoperative diagnostic evaluation of a posterior mediastinal mass should include posteroanterior and lateral chest roentgenograms, and either CT or MRI of the chest and abdomen to assess the extent of the mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Life-threatening respiratory distress caused by a mediastinal teratoma in a newborn

Mediastinal teratomas rarely cause symptoms in newborns. Case reports drawing attention to this presentation have appeared in the literature. A 2-day-old baby with respiratory distress treated by intubation and mechanical ventilation underwent an urgent thoracotomy to alleviate tracheal compression that was caused by a teratoma. The clinical, radiological, and surgical features related to this case are reported.

Juvenile hemangiomas involving the thoracic trachea in children: report of two cases

Two 3-month-old girls presented with posterior mediastinal juvenile hemangioma (JH), a benign tumor rarely found in the mediastinum. Incomplete resections were performed. Over 4 and 7 months, respectively, the hemangiomas recurred and grew through the tracheal wall into the tracheal lumina, reducing the airway by 90% in one case and 70% in the other. The recurrences were resected, including five tracheal rings in the first case and four in the second. In case 1 the tumor recurred in the trachea 2 months later. A tracheostomy was performed, and corticosteroids were administered for 6 months. The tumor involuted and the patient was decannulated after 18 months; she is doing well 7 years later. The patient in case 2 has been well in the 18 months since her second operation. Airway obstructions can be treated by tracheal resection when conservative management fails.

Mediastinal masses in childhood: a review from a paediatric pathologist's point of view

From 1970 to 1989, 121 children with mediastinal masses of various sorts were seen in the Department of Pathology, Royal Children's Hospital, Melbourne. The series is considered representative of the true incidence of these conditions in the state of Victoria, which had an average paediatric population during the time of this series of 900,000 children. The commonest cause of a mediastinal mass was NHL (36 cases). This was followed by HD (24 cases), then neuroblastoma and ganglioneuroma (16 and 9 cases respectively), duplication cysts (10 cases), teratomas (7 cases), neurofibroma (4 cases) and lymphangioma (3 cases). A great variety of rare conditions made up the remainder of the series and included mediastinal abscess, thymic cyst, pericardial cyst, accessory lobe of lung, plasma cell granuloma, fibromatosis, paravertebral Ewing's tumour, carcinoid tumour and neurofibrosarcoma. Presentation of the children with NHL was often acute with respiratory distress, while the child with HD was usually older and symptoms were more often systemic than local. The surgeon's role in diagnosis of these most frequently encountered mediastinal masses can be crucial and biopsy when indicated must be carried out with great care to produce material that is adequate for diagnosis and for the performance of cell marker studies and chromosome analysis. Neuroblastoma (NBL) and ganglioneuroma (GN) together were the third largest group. Children with neuroblastoma were usually young; 15 of the 18 cases were less than 2 years old. One-third of the infants with neuroblastoma presented with paraplegia and one-third with respiratory symptoms including wheeze, stridor and respiratory difficulty. Three children had Horner's syndrome. Prognosis of children with thoracic neuroblastoma is very good and contrasts with the poor outlook for those with abdominal neuroblastoma. Stage at presentation is probably the most important single prognostic variable. Ganglioneuroma presents at a later age than neuroblastoma and symptoms may be present for a long time or may be completely absent. Catecholamines, usually raised in neuroblastoma, are mostly normal in ganglioneuroma. Duplication cysts were the next most frequent group. Symptoms can often be acute and life threatening, although in three of our ten cases the cyst was an incidental finding on chest X-ray. However, only three of our patients had a normal respiratory examination. Teratomas were usually large and more often benign than malignant. Excision is the mandatory treatment and is usually curative. Although teratomas in young infants are often cellular and composed of many immature tissue types, their behaviour is benign.(ABSTRACT TRUNCATED AT 400 WORDS)

Mediastinal tumours. A report of 129 cases

Primary mediastinal tumour or cyst was surgically treated in 129 patients (including 19 younger than 12 years) during a 16-year period. All histologic specimens and smears from fine-needle aspiration biopsy were reviewed. Intrathoracic goitre, neurogenic lesions and thymomas comprised 62% of all the tumours. Fifty lesions (39%) were found at routine radiographic examination and were asymptomatic. Eight of these 50 lesions were malignant. Chest pain, fatigue, weight loss and fever were significantly more common in malignant than in benign disease. Despite extensive investigations, the diagnosis was not established preoperatively in 32% of the cases. Chest radiography, CT-scanning and fine-needle aspiration biopsy usually provide satisfactory diagnostic information, thereby substantially reducing the need for other preoperative procedures. Early operative intervention is mandatory in these cases.

Huge prepericardial tuberculous abscess in a 2-year-old child

A 2-year-old girl presented with recurrent episodes of respiratory infection and was not thriving well. Investigation showed a huge cystic mass in the anterior mediastinum just in front of the heart. Exploration showed a massive cystic swelling with enormously thickened wall anterior to the heart. The mass was excised, and histopathology showed it to be of tuberculous origin.

Giant cystic hygroma of the posterior mediastinum

The case of a 5-year-old girl with a giant cystic hygroma of the posterior mediastinum is reported. Although the tumor was bilateral, it was excised by unilateral thoractomy. The unique anatomical features of this tumor suggested an embryologic origin from the cisterna chyli or the primitive paired thoracic ducts.

Computed tomography and magnetic resonance imaging diagnosis of thymic cyst

A case of mediastinal thymic cyst evaluated by computed tomography and magnetic resonance imaging is presented. The anterior mediastinal mass was well-demarcated and measured 10 Hounsfield units on the computed tomographic scan. The lesion showed intermediate signal intensity on T1-weighting and became hyperintense on T2-weighted images. These computed tomography and magnetic resonance imaging features suggested a cystic structure, which proved to be a benign thymic cyst on pathologic examination.

Primary cysts and neoplasms of the mediastinum: recent changes in clinical presentation, methods of diagnosis, management, and results

Major changes have recently occurred in the clinical presentation, diagnosis, and management of primary lesions of the mediastinum. New diagnostic techniques and improved therapy have led to more objective preoperative diagnoses as well as better long-term results. These features are clearly demonstrated in a series of 400 consecutive patients with primary lesions of the mediastinum seen at Duke University Medical Center. Of these, 99 (25%) had a primary cystic lesion. The primary tumors included thymic neoplasms (17%), neurogenic tumors (14%), lymphoma (16%), germ cell tumors (11%), and a miscellaneous group. Malignant neoplasms were present in 166 patients (42%). The anterosuperior mediastinum was the most commonly involved site of a primary cyst or neoplasm (54%), followed by the posterior mediastinum (26%) and the middle mediastinum (20%). Symptoms were present in 62% of the patients and included chest pain (30%), dyspnea (16%), fever and chills (20%), and cough (16%). Of the lesions found on routine chest roentgenograms, 83% were benign. In contrast, 57% of the lesions in symptomatic patients were malignant. Prior to 1967, 94% of asymptomatic lesions were benign, but this figure has now decreased to 76%. Fifty percent of symptomatic patients had a malignant neoplasm before 1967 compared with 62% after that year. Newer diagnostic techniques have greatly enhanced the accuracy of the preoperative diagnosis. They include radioisotopic scanning, monoclonal antibodies, hormonal assay, electron microscopy, fine-needle aspiration biopsy, computed tomographic scans, and magnetic resonance imaging. Each has a definite role and is specifically illustrated as being quite important in this series.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary anterior mediastinal tumors in children and adults

This review details pertinent anatomical, radiological, pathological, and clinical information regarding primary anterior mediastinal tumors. Although the majority of these lesions are included in one of several subgroups, for example, thymic tumors, teratomas, or thyroid abnormalities, other less common entities will occasionally be encountered by the practicing surgeon. Likewise, there are variations in the frequency distribution of anterior mediastinal lesions in children as opposed to adults. Management of these individual lesions is outlined.

Diagnostic dilemmas of mediastinal cysts

Children with foregut cysts of the mediastinum can present at any age with nonspecific respiratory symptoms or dysphagia. Chest radiograph and barium esophagram are recommended for initial evaluation, but they fail to identify some lesions. In other cases, an obvious mass may be confused with a solid neoplasm. We have operated upon 34 infants and children with mediastinal bronchogenic cysts and esophageal duplications from 1968 through 1985. This review of their clinical course and radiographic imaging studies emphasizes some of the diagnostic pitfalls that lead to operative delay. Twelve (35%) of these patients were asymptomatic. The correct diagnosis was delayed longer than 3 months from the onset of symptoms in 14 of the 22 symptomatic children. Fifteen of these presented with pneumonia or symptoms or airway obstruction. In 11, the cyst was in a perihilar or subcarinal location, areas in which a lesion can be "hidden" behind the cardiac silhouette. Five children with esophageal duplication had severe neonatal respiratory failure, chest pain, hematemesis or dysphagia. The immediate preop chest radiograph revealed a mass in 29 of 34 cases. However, the lesion was initially missed or never seen in eight of those who were symptomatic. Esophagram, performed in 23, was diagnostic in only six and was normal in four. Prior to 1979 when CT scanning became available at this institution, 11 of 19 children (57%) underwent extensive work-up, but the preop diagnosis was correct in only 50%. Since 1979, only 4 of 15 (26%) have required similar evaluation, and the preop diagnosis has been correct in all.(ABSTRACT TRUNCATED AT 250 WORDS)

Computerized tomography and ultrasonographic findings in massive thymic hyperplasia. Case discussion and review of current concepts

Massive thymic hyperplasia in the neonate and young infant can be difficult to diagnose. Differentiation from neoplastic lesions may require thoracotomy for a pathologic specimen. We review a case in a 15-month-old child referred to our institution and discuss the radiographic, ultrasound, and computerized tomographic features of hyperplastic thymic tissue. We review current concepts of the hyperplastic thymus as an anterior mediastinal mass in infancy.

Anaesthesia and mediastinal masses. A case report and review of the literature

A case in which a mediastinal tumour caused complications including airway obstruction unrelieved by intubation during inhalational induction is described. Other case reports are reviewed and the anaesthetic management of patients with mediastinal tumours is discussed.

Mediastinal masses. Clues to interpretation of radiologic studies

The best approach to evaluation of a mediastinal mass begins with a history and a physical examination that are oriented toward discovery of evidence of compression or obstruction to any of the mediastinal organs. Currently, the most efficient radiographic approach, after the plain chest roentgenogram, is computed tomography of the thorax, supplemented as needed by selected plain tomograms or a barium swallow examination. Unless the mass is definitely a benign lesion of no consequence, such as a pericardial fat pad, thoracotomy by an experienced thoracic surgeon is usually necessary to make a specific diagnosis and excision is performed if possible.

Computed tomography of the thymus of children under 10 years

The CT appearance of the mediastinum of 27 patients under 10 years of age was analysed retrospectively, paying special attention to the anterior mediastinum and thymus. None of the patients had thymic disease. The purpose of the study was to record features which might be regarded as characteristic of the normal thymus. The lateral contour of the thymus was clearly seen. There were no infiltrations, but in one case there were displacements due to a prominent thymus. All the thymus glands appeared to be homogeneous. The use of contrast medium helped in distinguishing the thymus from other mediastinal structures; its use is well justified in studying the anterior mediastinum.

Benign hemangioendothelioma--a rare type of posterior mediastinal mass in children

Two infants with benign hemangioendotheliomas of the posterior mediastinum are reported here. The neoplasms did not produce symptoms and were fortuitously discovered by chest roentgenograms. Computed tomography (CT) was useful in delineating the extent of the lesions preoperatively.

Cardiac tamponade caused by a mediastinal teratoma

Mediastinal masses in children younger than 2 years often cause symptoms from tracheal compression, but clinical indications later in childhood are less frequent. Mediastinal teratomata arise in the anterior region, and when they produce symptoms these are usually manifestations of tracheal compression, pain, pleural perforation or secondary infection of the tumour. Pericardial perforation is a rare and life-threatening complication. A case of sudden pericardial perforation and cardiac tamponade caused by a mediastinal teratoma is described.

Primary mediastinal tumors in children

Mediastinal masses in children constitute a heterogeneous group of malignant and benign neoplasms. The majority of malignant tumors in our series of 188 children with a mediastinal mass were Hodgkin's and non-Hodgkin's lymphoma (87 patients) arising in the anterior and middle mediastinum. Ganglioneuroma (17) arising in the posterior mediastinum made up the bulk of benign tumors (52). Infants less than 2 yr old presented with symptoms of tracheal compression, whereas older children had fewer symptoms but a far greater likelihood of having a malignancy. In the assessment of patients with mediastinal tumors, the posteroanterior and lateral chest roentgenograms were most often diagnostic, and computed tomography of the chest provided the most information concerning preoperative resectability. The excellent survival of patients with stage I and II Hodgkin's disease reflects the radiosensitivity of the tumor; in our series of 33 patients, survival was not increased by radical resection. Unlike lymphomatous tumors, neurogenic masses should be completely excised. When initial exploration reveals unresectability, biopsy followed by radiation therapy and second-look excision of the tumor can be accomplished. In patients with primary mediastinal sarcomas, total resection should be carried out if possible. In our series, adjuvant radiation therapy or chemotherapy was effective in only 1 of 15 children with sarcoma. Surgical treatment of all mediastinal masses except lymphoma should be complete excision. In cases of suspected lymphoma, cervical or supraclavicular node biopsy can yield adequate tissue for diagnosis.

Benign clinical behavior of immature mediastinal teratoma in infancy and childhood: report of two cases and review of the literature

Germ cell tumors of the mediastinum can be divided into three categories: 1) mature teratomas which have all elements at a mature level; 2) immature teratomas which are similar to the mature teratomas, but also contain immature epithelial or mesenchymal elements or blastema; and 3) embryonal tumors which contains elements which are recognized as dysgerminoma, embryonal carcinoma with or without yolk sac elements, and choriocarcinoma. Immature teratomas are the rarest type, accounting for only about 1% of mediastinal teratomas. Two cases of immature teratoma of the mediastinum occurring in infants are reported. One tumor was completely excised. The child is well without evidence of disease two years later. The other immature teratoma was unresectable. Biopsy showed it to be similar to the teratoma that was excised. No postoperative treatment was given. The tumor has not changed appreciably in size, but the child has grown normally for six years so that the tumor mass, which initially filled his chest, is now evidenced as mediastinal widening. A review of the reported cases of immature teratomas in the mediastinum shows that the prognostic value of the histologic appearance of these tumors has not been developed to the same degree as it has for teratomas in the ovary or the sacrococcygeal region. The immature teratomas that occur in infants behave as mass lesions as do the mature teratomas. Immature teratomas in the mediastinum of children in their late teens and in young adults behave as highly malignant tumors similar to the embryonal carcinomas.

Bronchogenic cyst

Two recent patients with bronchogenic cysts, presenting in an atypical manner, stimulated our review of this subject. Twenty patients with bronchogenic cysts have been treated at the Boston Floating Hospital over the past 20 yr. Of these patients, 19 out of 20 were symptomatic, the most common symptom being fever (6 out of 20). Half of our patients had no respiratory symptoms but only one was found to have an asymptomatic mass on chest x-ray. The majority of theses cysts were found within the pulmonary parenchyma, the right lung being affected three times more commonly than the left. These facts are at odds with the reports in the literature. Three were found in the neck. Bronchogenic cysts are generally thought to be small, solitary, and limited in area. However, a significant number in our series (8 out of 20) were large, multiple or multicystic, and involved segments, lobes, multiple lobes, and, on one occasion, an entire lung. The correct pre-operative diagnosis was made in only 30% of the cases. The fact that the diagnosis was often missed led to long delays in treatment resulting in recurrent infectious complications and repeated hospitalizations. The most common cause of error in diagnosis was failure to follow a pneumonia to complete resolution. Despite the frequent delays in diagnosis, surgical treatment was curative in all patients.

Mediastinal tumours and cysts. A review of 91 cases

The experience with 91 primary tumours of the mediastinum during a period of 20 years is presented. A total of 24 separate cell types were identified. The most frequent lesions were thyroid tumours, neurogenic tumours, cysts and tumours of lymphatic origin. About 50% of the tumours were discovered by chance in asymptomatic patients undergoing routine chest examination. Twenty per cent of the patients with malignant lesions were free of symptoms. The pre-operative diagnosis was uncertain in most instances, and early surgical exploration is therefore recommended. Seventy-four patients underwent surgery and the operative mortality rate was 2.7%. The long-term survival was closely related to the histological nature of the neoplasm.

Malignant mediastinal teratoma in a 15-year-old girl

A well-differentiated anterior mediastinal teratoma was removed from the right hemithorax of a 15-year-old girl presenting initially with ascites. Death followed a precipitous clinical deterioration from widespread sarcomatous metastatic disease. The true malignant nature of this tumor was not apparent on initial resection and evaded detection until shortly before death. These unique features prompted a review of the pertinent literature on malignant mediastinal teratoma in children. A similar case had not been reported previously.

Thymus related tumors and tumor-like lesions in childhood with rapid clinical progression and death

Tumor and tumor-like lesions of the thymus, excluding Hodgkin and nonHodgkin lymphomas, are among the least frequent mediastinal tumors in childhood. For this reason the diagnosis is often overlooked. The clinical and pathologic features of four thymus related masses, three of which were thymomas and one a thymic cyst, are reported in children between the ages of five and 15 years. The thymic cyst occurred in a child with a five year history of aplastic anemia. A rapid clinical course to death occurred in all four cases. The behavior of these lesions is compared with that described in the literature. The impression exists that thymomas in the pediatric age group are much more aggressive than those in adults. There are also some signifant differences in their histopathologic appearance.

Physiological activity in mediastinal teratomata

The clinical details of two patients with benign mediastinal teratomata are presented. Both patients developed inflammation of the root of the neck, the first after a small dose of radiotherapy and the second after a larger dose of radiotherapy and exploration of the thoracic inlet. In both cases, exploration of the inflamed area was followed by persistent discharge of fluid which was sterile on culture. In the first case, this was found to have a high cholesterol, lipid, and amylase content. In both cases, a benign mixed teratoma, with contents including intestinal epithelium and pancreatic tissue, was removed at thoracotomy. The suggestion is made that leakage of digestive enzymes from pancreatic, intestinal or salivary tissue may be a cause of inflammation in and around teratomata, especially after surgical exploration. Early thoracotomy is advised when the condition is recognized.

Tumours of the thymic region. Symptomatology, diagnosis, treatment, and prognosis

Fifty-three patients operated on between 1952 and 1971 were originally diagnosed as having thymoma. Re-examination of the material shows that only half of these tumours were true thymomas. The rest were classified as malignant lymphomas, primary and secondary carcinomas, and a few haemangiomas. Half of the patients had symptoms at the time of diagnosis. However, in half of the asymptomatic cases the tumours had penetrated the capsule. Decisive in prognosis are the macroscopic findings around the capsule. Of 33 patients with infiltration of the capsule, 30 had died at the time of investigation. Twenty-five patients died within two years of operation, Twenty-five patients had thymomas, of which 14 were well defined. Twelve patients with thymomas suffered from myasthenia gravis. The treatment of choice of thymoma is total excision, if necessary enbloc, and if there is penetration of the capsule, radiotherapy should be given. None of the patients with a well-defined thymoma had died from their tumour while only two patients with infiltrating thymomas are still alive, Of eight patients with Hodgkin's disease located in the thymus, six had penetration of the capsule, and of these only one patient is still alive. Two patients with well-defined tumours are both alive. The treatment of localized Hodgkin's disease is excision and irradiation. The prognosis for patients with other malignant tumours was bad, the mean time of survival being less than six months.

Primary mediastinal tumours

Al-Naaman, Y. D., Al-Ani, M. S., and Al-Omeri, M. M. (1974).Thorax, 29, 475-481. Primary mediastinal tumours. A review of 28 patients with primary mediastinal tumours seen over a five-year period is presented. Clinical and pathological features of a heterogeneous group of tumours are emphasized. Since a number of patients presented with mild symptoms or were asymptomatic (especially adults), the importance of routine chest radiographs is stressed. Complete excision was accomplished in all patients with benign lesions. Malignant lesions were usually partially resectable and carried a poor prognosis.