Primary rhabdomyosarcoma of the bronchus

Primary Pulmonary Alveolar Rhabdomyosarcoma in a Pediatric Patient: A Case Report With Literature Review

Rhabdomyosarcoma (RMS) is a rare soft tissue tumor originating from skeletal muscle that is mostly reported in children. The most common sites of involvement are the head, neck, and extremities. The 2020 WHO classification divide RMS into four types: embryonal, alveolar, pleomorphic, and spindle cell/sclerosing. Reports of RMS with primary lung origin are rare. We present a case of RMS in a 16-month-old boy who presented with a lung mass and microscopic examination with fluorescence in situ hybridization confirmed the diagnosis of alveolar RMS. In conclusion, RMS should be considered in the differential diagnosis of any lung mass with small round blue cell morphology in the microscopic evaluation and should be distinguished from metastatic RMS of other sites, pleuropulmonary blastoma, lymphoma, neuroblastoma, primitive neuroectodermal tumor (PNET)/EWING, and malignant peripheral nerve sheet tumors (MPNST).

Primary and metastatic lung tumors in the pediatric population: a review and 25-year experience at a large children's hospital

CONTEXT

Primary lung neoplasms are rare in children, but they comprise a broad and interesting spectrum of lesions, some of which are familiar from other tissue sites, and some of which are unique to the pediatric lung.

OBJECTIVE

To determine the relative incidence of primary and metastatic lung tumors in children and adolescents through a single-institution case series, to compare these data to reports in the medical literature, to discuss the clinical and pathologic features of primary tumors of the tracheobronchial tree and lung parenchyma in children, and to provide recommendations for handling pediatric lung cysts and tumors.

DATA SOURCES

A 25-year single institutional experience with pediatric lung tumors, based on surgical biopsies and resections at Texas Children's Hospital from June 1982 to May 2007, an additional 40 lung tumors referred in consultation, and a review of the medical literature.

CONCLUSIONS

A total of 204 pediatric lung tumors were diagnosed at our institution, including 20 primary benign lesions (9.8%), 14 primary malignant lesions (6.9%), and 170 secondary lung lesions (83.3%). The ratio of primary benign to primary malignant to secondary malignant neoplasms is 1.4:1:11.6. The common types of lung cancer in adults are exceptional occurrences in the pediatric population. The most common primary lung malignancies in children are pleuropulmonary blastoma and carcinoid tumor. Other primary pediatric lung tumors include congenital peribronchial myofibroblastic tumor and other myofibroblastic lesions, sarcomas, carcinoma, and mesothelioma. Children with primary or acquired immunodeficiency are at risk for Epstein-Barr virus-related smooth muscle tumors, lymphoma, and lymphoproliferative disorders. Metastatic lung tumors are relatively common in children and also comprise a spectrum of neoplasia distinct from the adult population.

Epithelial and soft tissue tumors of the tracheobronchial tree

This article provides a broad overview of tumors that can involve the tracheobronchial tree. For the most part, the clinical, radiographic, and endoscopic presentation of these rare tumors does not differ significantly from the more common tumors of the lung. Appropriate classification of many tracheobronchial tumors ultimately requires complete sampling and a thorough microscopic evaluation. The introduction of ancillary diagnostic techniques such as immunohistochemistry and molecular analysis will continue to refine tumor classification.

Primary pulmonary rhabdomyosarcoma arising within cystic adenomatoid malformation: a case report and review of the literature

The current report describes a 13-month-old boy with primary pulmonary rhabdomyosarcoma (RMS) that originated within a congenital cystic adenomatoid malformation (CCAM). To the best of our knowledge, he is the youngest patient of all primary pulmonary RMS cases reported in the English-language literature. The tumor, localized in left upper lobe, was removed completely, and histologic examination showed embryonal subtype. Postoperative systemic chemotherapy was carried out. Recent evaluation 15 months after resection has not identified any residual or recurrent disease. Primary pulmonary RMS, although very rare in the pediatric age group, should be considered in young patients with solitary pulmonary masses and associated cystic lesions.

Fine-needle aspiration cytology of pleuropulmonary blastoma: case report and review of the literature

This report describes the fine-needle aspiration (FNA) cytology of a case of pleuropulmonary blastoma in a 3-yr-9-mo-old male. Pleuropulmonary blastoma is considered by most authors to be distinct from pulmonary blastoma and is a rare malignant tumor of the intrathoracic cavity. FNA smears were cellular with numerous small ovoid to spindled cells with oval to elliptical nuclei exhibiting finely granular chromatin and inconspicuous nucleoli. The cytoplasm was scant and eosinophilic with indistinct borders. Focal chondroid material and blastema-like cells were noted. The differential diagnosis suggested by the cytologic findings included rhabdomysosarcoma, teratoma, neuroblastoma, malignant mesenchymoma, pleuropulmonary blastoma, and metastatic tumor. To our knowledge, this is the first report of the cytology of this tumor.

Primary pulmonary rhabdomyosarcoma in childhood: clinico-biologic features in two cases with review of the literature

The cases of two children under three years of age with primary pulmonary rhabdomyosarcoma and no associated lung malformations are reported and a review of the literature is presented. In both, complete surgical removal of the tumor was performed and histologic examination revealed embryonal subtype. Flow cytometric assessment showed a tumor-cell diploid DNA content. Postoperative radio- and chemotherapy were carried out, but in spite of treatment both girls died because of disease progression, fourteen and nine months after diagnosis. The importance of associated cystic lung malformations and DNA content in predicting clinical outcome of primary pulmonary rhabdomyosarcoma is evaluated.

Alveolar rhabdomyosarcoma of the lung in a child

The case of a 22-month-old boy with alveolar rhabdomyosarcoma of the lung is presented. Brain metastasis and recurrence of the right pulmonary hilum and parietal pleura developed 6, 11, and 24 months (respectively) after tumor resection. Chemotherapy and radiotherapy were effective. Neuron-specific enolase was very helpful in detecting metastasis and disease recurrence. Primary pulmonary rhabdomyosarcoma can be divided into two groups: tumor in the normal lung, and tumor in cystic lesions of the lung.

Rhabdomyosarcoma arising within congenital pulmonary cysts: report of three cases

Over the past 9 months, three cases of primary pulmonary rhabdomyosarcoma have been treated at British Columbia Children's Hospital. Two patients (aged 24 and 37 months) presented with spontaneous pneumothoraces and had cystic changes in the affected lung on chest radiograph. The third patient (aged 42 months) was evaluated for chronic cough, fever, and failure to thrive. Chest x-ray showed a large mass in the left lower lobe as well as mediastinal adenopathy. All three of these lesions originated within congenital lung cysts, one a peripheral bronchogenic cyst and the others cystic adenomatoid malformations. This report suggests that there is a significant risk for the development of rhabdomyosarcoma within malformed pulmonary tissue.

A case of small round cell tumor of the thoracopulmonary region with myogenic and neurogenic elements

We here report a unique case of a young boy with an intrathoracic tumor which consisted of neurogenic and myogenic elements. The initial pathological diagnosis was alveolar rhabdomyosarcoma. The tumor tissue from surgical resection was composed of three parts, each showing a different histological appearance, i.e. a monotonous small cell area, an alveolar area, and an area consisting of pleomorphic rhabdomyoblasts. The small round cells in the monotonous area were immunoreactive with the antibodies for Leu7, neuron-specific enolase (NSE), neurofilament proteins (NFP), and beta 2 microglobulin, but not with the antibody for desmin. These cells also had dense core granules. The tumor cells in the alveolar area were immunoreactive with the antibodies for Leu7 and desmin, but not with the antibody for NFP. Pleomorphic rhabdomyoblasts were immunoreactive with the antibody for desmin, but not with the antibodies for Leu7 and NFP. These findings imply that this tumor consisted of neurogenic and myogenic elements and is considered to be a special type of rhabdomyosarcoma.

Childhood pulmonary blastoma: a pleuropulmonary variant of the adult-type pulmonary blastoma

Two fatal childhood cases of the rare pulmonary blastoma are reported. One was associated with a congenital cystic adenomatoid malformation. Both neoplasms extended to involve visceral pleura and were entirely composed of blastemal and mesenchymal elements without recognizable neoplastic epithelial components. The mesenchymal component in both instances consisted of malignant rhabdomyoblasts, undifferentiated mesenchyme, and differentiated, apparently benign, cartilage. Review of the literature suggests that these features may be specific for the childhood forms of pulmonary blastoma. It is further suggested that pulmonary blastoma, malignant mesenchymoma of the lung, and primary pulmonary rhabdomyosarcoma may have a common pathogenetic origin.

Malignant mesenchymoma associated with a congenital lung cyst in a child: case report and review of the literature

Primary lung tumors are uncommon in children, and malignant mesenchymal tumors form only a small proportion of these. Leiomyosarcomas occur more commonly than rhabdomyosarcomas, whereas malignant mesenchymomas are exceedingly rare. Of the total number of primary pulmonary rhabdomyosarcomas and malignant mesenchymomas of lung reported in children, 50% have occurred in association with congenital lung cysts. The relationship between abnormal morphogenesis and neoplasia is well documented in the kidney. A similar relationship may exist in the lung between cystic parenchymal maldevelopment and embryonal mesenchymal tumors. We report a 4-year-old boy with a malignant mesenchymoma of lung arising within a congenital lung cyst; one similar case has previously been reported to our knowledge.

Primary bronchopulmonary fibrosarcoma of childhood and adolescence: reassessment of a low-grade malignancy. Clinicopathologic study of five cases and review of the literature

In children, primary tumors of the lung constitute a unique subset of quasineoplastic and unequivocally neoplastic lesions whose benign or malignant potential is not always predictable on the basis of morphologic findings. One such neoplasm in the latter category is the primary bronchopulmonary fibrosarcoma (PBPF). This clinicopathologic, ultrastructural, and immunohistochemical study documents our experience with five PBPFs in newborns and children up to 11 years of age at diagnosis. The tumors were either endobronchial or intraparenchymal in location. A uniform population of interlacing bundles and sheets of densely arranged spindle cells with variable mitotic activity was observed microscopically in each case. Ultrastructurally, the cells had the features of fibroblasts and vimentin was the only immunohistochemical marker identified. Despite the disturbing pathologic findings, the four children with more than 1 year of follow-up have survived well 4 to 9 years after surgical resection. Our results are compared with the 21 cases of PBPF reported in the literature and the differential diagnosis is discussed.

Primary tracheal rhabdomyosarcoma. Case report

A case of primary tracheal rhabdomyosarcoma is presented--the second in the English-language literature. The treatment policy is discussed on the basis of this case and the literature is reviewed.

Primary pulmonary rhabdomyosarcoma in a child, with a review of literature

A cyst in the left lower lobe of the lung was removed from a 15-month-old girl and showed evidence suggesting a preexistent congenital cystic adenomatoid malformation; in addition a rhabdomyosarcoma was identified. Primitive mesenchyme and mesenchymal elements also were seen. The origin of the rhabdomyosarcoma is discussed. The findings in the present case are compared with those of all childhood pulmonary rhabdomyosarcomas reported in the literature. This report of a child with a coexistent congenital adenomatoid malformation and a rhabdomyosarcoma is the third of its kind in the literature.

Primary pulmonary rhabdomyosarcoma of the lung in children. Report of two cases presenting with spontaneous pneumothorax

This report describes two cases of pulmonary rhabdomyosarcoma occurring in children, ages 21 and 30 months at diagnosis. Both patients presented with spontaneous pneumothorax and had cystic changes in the affected lung by chest x-ray. Ultrastructural and immunohistochemical studies supported the myogenic phenotype of these neoplasms. The authors were unable to confirm that either of these tumors had unequivocally originated in a congenital cyst although previous authors have reported this association. An apparent morphologic spectrum of embryonic appearing neoplasms including pulmonary blastoma and a malignant mesenchymoma have been observed in the lungs of children.

Primary pulmonary neoplasms of childhood: a review

Primary tumors of the lung rarely occur in children. However, 230 well-documented cases, including the 2 presented in this review, have been identified in the English-language literature. One hundred fifty-one tumors in these reports were classified as malignant lesions and 79 as benign neoplasms. Bronchial "adenomas" constituted the largest group; most of these lesions were of the carcinoid variety, and 8% were definitely malignant. Forty-seven cases of bronchogenic carcinoma were reported in children under 16 years of age, although there were few squamous cell tumors (12%). Fifty-six percent of the benign tumors were classified as inflammatory pseudotumor. Most of the children in this collective series were seen with symptoms related to bronchial irritation or obstruction, such as cough, hemoptysis, atelectasis, or pneumonitis. Respiratory distress was an unusual symptom that was often associated with large tumors seen in the neonatal period. Approximately 20% of the children were totally symptomatic. The limited survival data that are available indicate that leiomyosarcoma and mucoepidermoid carcinoma have a more favorable prognosis in children than in adults. Survival with bronchial carcinoid tumors (90%), bronchogenic carcinoma (30%), and pulmonary blastoma (45%) appears to parallel that for adults. The experience with pulmonary rhabdomyosarcoma, as described in this review, emphasizes the importance of early diagnosis and the use of combined modes of therapy in the approach to these malignancies. Despite the rarity of primary pulmonary neoplasms in children, this diagnosis should be considered in young patients with solitary pulmonary masses or persistent, atypical pulmonary symptoms. It is hoped that early diagnosis will result in an improved prognosis and prevent life-threatening complications.

Primary pulmonary rhabdomyosarcoma: a case report and review of the literature

Although several primary pulmonary neoplasms containing striated muscle fibers have in the past been described as rhabdomyoma or rhabdomyosarcoma, it was not until 1939 that McDonald and Heather described the first acceptable case of this neoplasm. Since then 13 such cases have been reported in the world literature. Previously reported cases of the neoplasm are reviewed and the salient features described. The origin of the striated muscle fibers has been much debated. Some believe that they develop from myoblastic differentiation of primitive mesenchymal cells or metaplastic transformation of pleuripotential mesenchymal cells present in the bronchial walls and pulmonary interstitium, whereas others claim that they develop from misplaced striated muscle tissue from the pharyngeal or esophageal region. A case report of the pleomorphic type of primary pulmonary rhabdomyosarcoma with multiple hematogenous metastases is presented as well as a review of the literature with a discussion of the histogenesis.

Malignant small cell tumor of the thoracopulmonary region in childhood: a distinctive clinicopathologic entity of uncertain histogenesis

This report describes a unique clinicopathologic entity characterized as a malignant small cell tumor of the thoracopulmonary region in 20 children and adolescents (average age 14.5 years). There was a female predilection (75%) for this tumor which appeared to originate in the soft tissues of the chest wall or the peripheral lung. The neoplasm tended to recur locally and did not seem to disseminate as widely as some of the other small cell tumors of childhood (rhabdomyosarcoma, Ewing's sarcoma, neuroblastoma and malignant lymphoma). However, the median survival was only 8 months. Electron microscopy of 3 cases suggested a neuroepithelial derivation, but, at the present, the histogeneis remains a subject for further investigation.

Rhabdomyosarcoma of lung arising in congenital cystic adenomatoid malformation

An asymptomatic congenital cystic adenomatoid malformation of lung discovered at age 18 months, and unchanging for 14 months prior to its removal, was found to harbor a small embryonal rhabdomyosarcoma following excision. With lobectomy and chemotherapy, the tumor-free interval has now exceeded three years. The case represents a well-documented occurrence of malignant tumor arising within a congenital malformation, an association that is unlikely to be the result of chance.