Pulmonary blastoma: report of a case

Pneumoblastoma: A Rare Tumor in Children Revealed by Pyopneumothorax

Pneumoblastoma is a rare but severely aggressive primary lung tumor. Exceptional at the pediatric age, pneumoblastoma lacks clinical and radiological specificity. It is rarely mentioned as a first-line differential, as radiological images are often confused with those of congenital lung malformation. This history is reminiscent of the diagnostic difficulty with which the clinician is confronted with the finding of an intrathoracic cystic image of the child. Primary childhood lung tumors, especially pneumoblastoma, are difficult to diagnose both clinically and by imaging. It is necessary to think about it in the face of any lingering respiratory infection and any atypical radiological presentation. We report this case in order to illustrate the usual radiographic, ultrasound, and scenographic aspects of this rare malignant tumor in children and to highlight the diagnostic problems posed by this exceptional pathology.

[Case report of pulmonary biphasic tumor with unusual follow-up]

BACKGROUND

Pulmonary blastoma, a rare primary lung malignancy is subdivided in 3 categories: well-differentiated fetal adenocarcinoma (WDFA), classic biphasic pulmonary blastoma (CBPB) and pleuropulmonary blastoma (PPB). Classic pulmonary blastoma is composed of a mixture of immature epithelial and mesenchymal tissue resembling fetal lung tissue.

CASE REPORT

We described a case of a 48-year-old male, cigarette smoker, who presented with left thoracic pain and hemoptysis for 2 months. Chest radiography showed a well-delimited, homogeneous 4cm mass in the left lung periphery. Bronchoscopic examination revealed left endobronchial bleeding. Computed tomography of the chest revealed a tumor shadow measuring 7cm in the left upper lobe and bilateral nodules with no lymphadenopathy. A systemic evaluation demonstrated no metastatic lesion. Patient underwent a left upper lobectomy. The diagnosis of CBPB was affirmed on anatomopathology of the tumor resection. Immunohistochemical studies showed that tumor cells were positive for vimentin, desmin, actin, Pan Cytokeratin and TTF-1. The final diagnosis was BPB classified as pathological T3N0M0 and no adjuvant treatment was associated. The patient showed good objective response with no evidence of disease recurrence still in 5 years surgery resection.

CONCLUSION

This case reiterates the importance of pathomorphological or immunohistochemical features in diagnosis of BPB.

Pulmonary blastoma with submandibular, scrotum and adrenal metastases: case report

A 62-year-old patient diagnosed with pulmonary blastoma with submandibular, scrotum and adrenal metastases was admitted to Sotiria General Hospital in Athens. No other such case has been published to date. The patient started receiving chemotherapy, but the scrotum metastasis grew rapidly and erupted. This led to sepsis despite surgical excision of infected and necrotic tissues and intravenous antibiotics. Treatment strategy in pulmonary blastoma should be defined by a multidisciplinary team, and surgical treatment should be considered as quickly as possible when such a tumor is suspected.

Pulmonary blastoma

We describe a resected pulmonary blastoma in an 84-year-old male, the oldest of previously reported patients. A chest X-ray showed a 2 cm-sized abnormal shadow in the left lung field. Five months later computed tomography demonstrated a well-demarcated heterogenous mass, measuring 12 cm in diameter, in the left lower lobe of the lung. This mass was diagnosed as a carcinoma using echo-guided percutaneous biopsy. The patient underwent a left lower lobectomy. The resected specimen revealed the tumor to be a pulmonary blastoma arising from lung tissue. Preoperative diagnosis of pulmonary blastoma is extremely difficult because of the histological heterogeneity of tumor. Since it has been noted that pulmonary blastoma rapidly progresses in a short period of time, surgical treatment should be undertaken as quickly as possible when such a tumor is suspected.

Case report: pulmonary blastoma: presentation of two atypical cases and review of the literature

Pulmonary blastoma is a relatively rare aggressive adult malignancy. The clinical and radiographic features of two cases are described and the literature reviewed. Pulmonary blastoma usually presents radiologically as a well-defined mass lesion on chest radiography, which may be large enough to completely opacify the hemithorax and cause mediastinal shift. On CT, pulmonary blastoma is seen as a mixed solid and cystic lesion with variable contrast enhancement and a necrotic centre. Pleural effusion may be present but is not the predominant abnormality. Our cases are unusual as recurrent pleural effusions in the absence of a significant lung mass were the presenting findings.

Aberrant Nuclear/Cytoplasmic Localization and Gene Mutation of β-Catenin in Classic Pulmonary Blastoma

It is now known that gene mutation of beta-catenin with subsequent nuclear/cytoplasmic (N/C) overaccumulation of the protein plays an important role in tumorigenesis of various organs. We recently demonstrated that low-grade adenocarcinoma of the fetal lung type (L-FLAC)/well-differentiated fetal adenocarcinoma (WDFA), the epithelial prototype of classic pulmonary blastoma (CPB), shows N/C localization of beta-catenin with genetic mutation. This prompted us to further investigate the state of beta-catenin abnormality in CPB and related neoplasms. We studied 9 lung tumors previously diagnosed as biphasic pulmonary blastoma (PB). Histologically, 4 cases (median age 34 years) were CPB with l-FLAC/WDFA as the epithelial component, whereas 5 cases (median age 65 years) were a variant of carcinosarcoma with high-grade FLAC/clear cell adenocarcinoma with fetal lung features as the epithelial component, which we term the blastomatoid variant of carcinosarcoma (BCS). Immunohistochemically, all 4 CPBs showed aberrant N/C localization of beta-catenin both in the epithelial and mesenchymal components, with especially high staining intensity in the budding glands and morules. In contrast, all 5 BCSs showed preserved or diminished membranous expression and no significant N/C expression of beta-catenin in the epithelial component, and absent or focal N/C expression of beta-catenin in the mesenchymal component. Mutational analysis of exon 3 of the beta-catenin gene revealed that 3 CPBs harbored missense mutations (S29F, S37F, and S37F), whereas none of the 5 BCSs had this mutation. This study suggests that beta-catenin gene mutations may play a role in the tumorigenesis of CPB. Although CPB and BCS have often been grouped together as biphasic PB, they are different entities based on immunohistochemical and molecular analysis of beta-catenin. Immunostaining for beta-catenin is useful for the discrimination.