Adrenocortical blastoma.

We report a previously undescribed virilizing malignant adrenocortical tumor in an 21-month-old infant with elevated serum alphafetoprotein. The tumor consists of a peculiar mixture of immature epithelial and mesenchymal elements as well as slit-like spaces partially lined by primitive epithelial cells. Focally, the tumor has features reminiscent of the normal embryologic development of the adrenal cortex. A panel of immunohistochemical stains revealed only vimentin reactivity. We propose the term "adrenocortical blastoma" for this unusual neoplasm.     

The cytomorphology of pleuropulmonary blastoma

Pleuropulmonary blastoma is a rare, primitive primary neoplasm of the thorax in young children. The tumor, which is often but not always associated with cystic lung lesions, may arise in pulmonary parenchyma, the mediastinum, and pleura. Histologically, it is characterized by a biphasic neoplastic population of undifferentiated-appearing small round cells and larger spindle-shaped cells. A proportion of these cancers may also manifest more specific mesenchymal differentiation. In contrast to the pulmonary blastoma of adults, a malignant epithelial component does not occur. We present herein the third known case of a fine needle aspiration biopsy of a pleuropulmonary blastoma in a 5-year-old girl. The smears were moderately cellular and included an admixture of the characteristic small ovoid blastemal elements and scattered spindled mesenchymal tumor cells.     

Pulmonary blastoma with germ cell (yolk sac) differentiation: report of two cases.

Pulmonary blastoma is a rare lung neoplasm of disputed histogenesis and variable biologic behavior. Typical cases contain both epithelial and mesenchymal tissues, and a variety of patterns of differentiation have been described. While expression of oncofetal antigens in these tumors has been noted rarely, a coexisting component of germ cell tumor has not been reported previously. We describe the clinical and pathologic features of two cases of pulmonary blastoma having alpha-fetoprotein production and histologic areas of yolk sac tumor. We also report the finding of immunohistochemical staining of fetal lung tissue for alpha-fetoprotein.     

Pleuropulmonary blastoma (pulmonary blastoma of childhood): genetic link with other embryonal malignancies?

A case of pleuropulmonary blastoma (childhood variant of pulmonary blastoma) was examined using histological, immunohistochemical, ultrastructural and cytogenetic methods. The tumour consisted of undifferentiated 'blastematous' areas admixed with zones of rhabdomyoblastic and chondroid differentiation and fascicular areas. Desmin and S-100 protein immunoreactivity confirmed the myogenic and cartilaginous differentiation. Ultrastructurally only undifferentiated mesenchymal cells were present. The cytogenetic analysis revealed abnormalities of 2q. Involvement of 2q has also been described in hepatoblastoma and embryonal rhabdomyosarcoma. Although further confirmation is needed, our cytogenetic findings in pleuropulmonary blastoma suggest common genetic mechanisms in some paediatric embryonal malignancies.     

Infant pleuropulmonary blastoma: report of a rare case and review of literature

In infants, pleuropulmonary blastoma is a rare but aggressive tumor. The typical histopathological presentation includes the aggregation of malignant primitive small cells, usually observed in sheets. So as to provide proper and timely treatment, the differential diagnosis includes pulmonary blastoma, sarcomatoid mesothelioma, fetal rhabdomyoma, synovial sarcoma, and primitive neuroectodermal tumor. Herein, we will present one male pediatric patient with pleuropulmonary blastoma. The patient was a 4-month-old male infant, who had a prolonged cough and dyspnea for 4 months that was complicated by cyanosis for 3 days. A physical examination revealed a solid mass in the right lung that was sized 9.0 × 6.0 × 4.0 cm and had a grayish-white cross section. The boundary between the mass and lung tissue was clear; the mass already occupied a great portion of the lung. A microscopic examination suggested that the tumor was composed of round or orbicular-ovate primitive fetal cells. The cells were medium sized, having little cytoplasm, but had a clearly visualized nucleolus and active karyokinesis. The tumor mass was biphasic, namely, fasciculated sarcoma (composed of spindle-shaped cells and short spindle-shaped cells) and malignant fibrous histiocytoma containing well-differentiated cartilage islands or cartilaginous nodes. Immunohistochemistry was performed for further detection: vimentin (+), S-100 protein (+), CK (AE1/AE3), EMA and TTF-1 in residual epithelial components (+), NSE (focal +), SMA (mesenchymal cells, focal +), CD99 (weak +), Bcl-2 (weak +), desmin (-), myoglobin (-), calretinin (-), calponin (-), FLI (-), MyoD-1 (-), and CD34 (-). Pleuropulmonary blastoma is extremely rare but highly aggressive neoplasm in children. Its typical histopathological presentation is the aggregation of primitive malignant small cells. Combining imaging and histopathological examinations and clinical data should help in determining the diagnosis of pleural pulmonary blastoma.     

Pulmonary blastoma and related primary malignant pulmonary neoplasms

During the last decade more diagnoses of pulmonary blastoma were made worldwide than in previous decades. Whether this increased frequency is caused by better diagnostic procedures (immunochemistry, electron microscopy) or by the growing number of patients having this neoplasm is difficult to distinguish. We present controversies concerning pulmonary blastoma and related biphasic primary pulmonary neoplasms. We agree with Wick et al. that cases in children (called pleuropulmonary blastoma) should be differentiated from cases in adults, which show many similarities to bronchogenic lung cancer. However, our opinion is that the new classification system proposed by Wick et al. does not take into account cases of PB in young adults with intropulmonary growth of the tumor.     

Pulmonary blastoma. Immunohistochemical and ultrastructural studies of a case

The immunohistochemical and ultrastructural features of a case of pulmonary blastoma in a 39-year-old woman are documented. Three types of cells were observed: epithelial, mesenchymal and 'blastomatous'. The latter stained with intermediate filament antibodies similar to those of mesenchymal and epithelial elements, thus supporting the hypothesis that this tumour is derived from a pluripotent undifferentiated element.     

Fine-needle aspiration cytology of pleuropulmonary blastoma: a case report with unusual features.

Pleuropulmonary blastoma (PPB) is a rare and aggressive intrathoracic neoplasm of childhood, typically presenting as a pulmonary and/or pleural-based mass with cystic, solid, or combined features. Histologically, the tumor is well characterized with a mixture of primitive mesenchymal and variably differentiated sarcomatous components, and the cytologic features described in the three previous reports are also compatible to the histologic ones. Now, we present another case of PPB showing unusual features. A 3-yr-old boy presented with a pleural- or chest wall-based tumor. The fine-needle aspiration cytologic smears were highly cellular with poorly differentiated cells showing variable size and shape rather than those of typical blastemal cells. The histologic findings were also distinctive, exhibiting diffuse sheets of poorly differentiated cells without typical blastemal cell component. Diagnosis was confirmed by the support of immunohistochemical and ultrastructural features. The patient underwent a typical aggressive clinical course to death within 8 mo after diagnosis.     

胸膜肺母细胞瘤1例报道及文献复习

目的：阐明胸膜肺母细胞瘤的病理形态特征及鉴别诊断要点。方法：对1例小儿胸膜肺母细胞瘤进行了组织形态学,免疫组织化学分析。结果：胸膜肺母细胞瘤是一种纯间质性恶性肿瘤,好发于12岁以下的儿童及婴幼儿,起源于肺、胸膜或纵隔的原始细胞,镜下可见原始胚胎性的圆形或短梭形细胞,瘤细胞有呈巢趋势,酷似肾母细胞瘤,肝母细胞瘤等肿瘤原始胚基成分,免疫组化未见有上皮细胞及其他间叶成分标志的表达,另一种成分为梭形细胞,除表现为纤维肉瘤特点外,还向横纹肌肉瘤分化,结论：胸膜肺母细胞瘤是一种极为罕见的恶性肿瘤,应与肺母细胞瘤,原始神经外胚叶肿瘤及胚胎性横纹肌肉瘤等鉴别。     

Pulmonary blastoma with malignant melanoma component

Pulmonary blastomas are rare primary tumors that consist of tubular or glandular structures embedded in an undifferentiated mesenchymal stroma. Focal cartilage, bone, and skeletal muscle as well as squamous differentiation have been described in these tumors. We report a unique case of a pulmonary blastoma showing a malignant melanoma component. Immunohistochemical stains for S100 protein and HMB-45 were positive in the areas of melanocytic differentiation.     

Pleuro-pulmonary blastoma in a 45 year-old woman after Hodgkin’s lymphoma: a case report

Pleuro-pulmonary blastoma is a rare and aggressive intrathoracic mesenchymal tumor occurring in childhood. We report the exceptional case of a forty-five year-old woman, presenting with respiratory distress. She had previously been treated with chemotherapy and radiotherapy for Hodgkin lymphoma. Chest X rays and computed tomography scan showed a left lung lower lobe mass and pleural effusion. Biopsy cores revealed a pleura-pulmonary blastoma tumor with mixed components. Neoadjuvant chemotherapy was decided in multidisciplinary round. Because of the rarity of these tumors, no consensus for the treatment exists.     

Pulmonary blastoma, a true congenital neoplasm

An infant, after a difficult delivery, had X-ray shadowing in the right lung. After 32 days sudden death occurred, a pulmonary blastoma being found at autopsy. The controversy over whether this tumour is a blastoma or a carcinosarcoma is discussed and arguments are advanced for acceptance of the designation pulmonary blastoma when the tumour occurs in infancy and childhood. When the equivalent tumour occurs in adults with or without the addition of areas of carcinoma and/or sarcoma, the title 'mixed tumour of lung' should replace the term carcinosarcoma.     

Pulmonary blastoma: a light-microscopic, immunohistochemical and electron-microscopic study of six cases in childhood]

Pulmonary blastoma is a very rare primary tumor of the lung, which mostly occur at a late age in adults. Six cases in children under four years of age are reported in this series. The light-microscopic, immunohistochemical and electron-microscopic characteristics revealed that the elements of P.B. in childhood consist mainly of mesenchymal components, including undifferentiated large cells and small round cells, which tend to differentiate toward rhabdomyosarcoma. The epithelial components comprise only a small portion of the total tumor, and most appear as the well-demarcate branching tubular structures lined with columnar or cubiodal epithelium merging with the stroma. The degree of differentiation of mesenchymal elements is closely related to the prognosis.     

Pulmonary blastoma

Summary A primary pulmonary tumour in a four year old boy arising from the subpleural zone of the lung is described. It contains both stromal and epithelial elements at the primary site and in the bony metastases. The combination of the age of the patient, the site of the tumour, the stromal and epithelial elements present in the tumour suggest that this is a true pulmonary blastoma. Electronmicroscopy showed the presence of intranuclear viral particles.     

Cell‐ and developmental stage‐specific Dicer1 ablation in the lung epithelium models cystic pleuropulmonary blastoma

Inherited syndromes provide unique opportunities to identify key regulatory mechanisms governing human disease. We previously identified germline loss‐of‐function DICER1 mutations in a human syndrome defined by the childhood lung neoplasm pleuropulmonary blastoma (PPB), which arises during lung development. DICER1 regulates many biological processes critical in development and disease pathogenesis. Significant challenges in defining the role of DICER1 in human disease are identifying cause–effect relationships and generating manipulatable systems that model the complexity of organ development and disease pathogenesis. Here we report the generation of a murine model for PPB and demonstrate that precise temporal and cell type‐specific Dicer1 ablation is necessary and sufficient for the development of cystic lungs that histologically and phenotypically model PPB. Dicer1 ablation in the distal airway epithelium during early stages of lung development resulted in a cystic lung phenotype indistinguishable from PPB, whereas DICER1 function was not required for development of the proximal airway epithelium or during later stages of organogenesis. Mechanistic studies demonstrate that Dicer1 loss results in epithelial cell death, followed by cystic airway dilatation accompanied by epithelial and mesenchymal proliferation. These studies define precise temporal and epithelial cell type‐specific DICER1 functions in the developing lung and demonstrate that loss of these DICER1 functions is sufficient for the development of cystic PPB. These results also provide evidence that PPB arise through a novel mechanism of non‐cell‐autonomous tumour initiation, in which the genetic abnormality initiating the neoplasm does not occur in the cells that ultimately transform, but rather occurs in a benign‐appearing epithelial cell component that predisposes underlying mesenchymal cells to malignant transformation. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Pulmonary blastoma

A case of pulmonary blastoma is described in a man dying at the age of 50 from hepatic and cerebral metastases. Eleven previously reported cases are reviewed and the histogenesis is discussed. It is concluded that these rare tumours are a distinct form of pulmonary carcinosarcoma in which the epithelial element is an adenocarcinoma. It is this that gives it its characteristic and probably coincidental histological resemblance to foetal lung and the evidence for a blastomatous origin is regarded as insufficient.     

Pulmonary blastoma in a child: Report of a case with cytological findings

Pulmonary blastoma is an uncommon tumour. It constitutes <0.1% of all resected lung cancers. It is even more rare in children with only a few case reports describing this entity in them. Pulmonary blastoma should not be confused with pleuropulmonary blastoma which is a paediatric lung tumour with different morphology and better outcome. Here we take the opportunity of describing pulmonary blastoma in a 3 years old child along with its cytological findings.     

Pleuropulmonary blastoma in a young adult presenting as a ruptured cystic teratoma in radiology

Pleuropulmonary blastoma (PPB) is a rare malignant dysontogenetic neoplasm primarily affecting children and is characterized histologically by a variably mixed blastematous and sarcomatous patterns. We herein report a very exceptional adult case of PPB. A 21-yr-old male patient presented with a left chest pain of two weeks' duration. A computed tomography scan revealed a large, multicystic tumor occupying the left lower hemithorax, leading to the impression of a ruptured mediastinal cystic teratoma. A thoracotomy for resection of the tumor was performed. On histologic examination, the tumor consisted of cystic walls and associated solid lesions which showed undifferentiated blastemal tissues with focal fibrosarcomatous and rhabdoid features. Immunohistochemically the tumor cells only showed diffuse strong positivity for vimentin. The histologic findings corresponded to a type II PPB. The authors suggest that PPB, especially of type I or II, should be included in the radiologic differential diagnosis of mediastinal cystic neoplasms in a young adult.     

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 cosinophilic 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. Diagn. Cytopathol. 16:336–340, 1997. © 1997 Wiley-Liss, Inc.