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。     

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 endodermal tumor resembling fetal lung: a clinicopathologic study of five cases with immunohistochemical and ultrastructural characterization

Pulmonary endodermal tumor resembling fetal lung describes an uncommon neoplasm of the lung which also has been referred to as pulmonary blastoma and adenocarcinoma of fetal lung type. We describe five cases which fall within a narrow band on the spectrum of pulmonary neoplasms with both epithelial and mesenchymal features. These five cases all occurred as well-defined masses visible on chest radiograph in middle-aged females, and were treated by surgical excision. Histopathologically, low and high grades of malignancy are found. Well-formed racimose glands with cytoplasmic vacuolization resemble endometrioid carcinoma. Neoplastic columnar cells have abundant glycogen in the cytoplasm. Morules of cells within the glands have optically clear nuclei. Ultrastructurally, the optically clear nuclei are occupied by a filamentous substructure of chromatin. Multiple neuroendocrine hormones are present in low-grade malignancy. Nuclear pleomorphism, lymphatic invasion, multifocal necrosis, lack of mesenchyme at the pulmonary interface, and restricted neuroendocrine expression suggest high-grade malignancy. A mesenchymal stroma surrounding the glands is an intrinsic part of the neoplasm, but the stroma does not appear malignant, and did not form part of the metastasis in the single case where a metastasis occurred. Stromal cells show fibroblastic and myofibroblastic differentiation. Pulmonary endodermal tumor resembling fetal lung typically is a low-grade malignancy, with a better prognosis than the majority of lesions sometimes described as pulmonary blastoma or adenocarcinoma of fetal lung type.     

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.     

Pulmonary blastomas. Immunohistochemical investigations of three cases

Three cases of pulmonary blastoma (PB) were investigated microscopically with conventional stainings and immunohistochemically with monoclonal antibodies to cytokeratin, vimentin, desmin and neurofilament protein. The tumors differed in terms of morphology as well as of immunohistochemistry. Two were epithelial and mesenchymal mixed tumors, and the remaining one was a monophasic tumor of a typical blastemic character. The two mixed tumors also differed from each other. In one of them, the epithelial and mesenchymal component expressed cytokeratin and vimentin in a clear-cut manner without any transition. The other mixed tumor displayed a gradual epithelial-to-mesenchymal transition accompanied by a switch in the expression of cytokeratin and vimentin. The third tumor was of pure mesenchymal origin, expressing vimentin in the majority of cells and desmin in few cells. It is concluded that the PB is a morphologically and histogenetically heterogeneous tumor. Metaplastic changes may take place within a PB and make the recognition of embryogenesis more difficult.     

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.     

Fine-needle aspiration cytology of pulmonary adenocarcinoma of fetal type: report of a case with immunohistochemical and ultrastructural studies.

This report describes the fine-needle aspiration (FNA) cytology of a case of adenocarcinoma resembling fetal lung in a 53-yr-old male, a very uncommon malignant tumor of the lung that is similar to an early stage of lung differentiation. FNA smears revealed relatively small, fairly uniform tumor cells appearing as cohesive cell groups and scattered, isolated cells, some of them showing a rosette or acinus pattern. In addition, clusters of larger cells with eosinophilic cytoplasm and prominent nucleoli existed contiguously with the small cells or separately. The possibilities of an unusual type of adenocarcinoma, carcinoid tumor, and pulmonary blastoma were suggested by the cytologic findings. Immunohistochemical studies performed on a resected tumor tissue showed immunoreactivity for alpha-fetoprotein, neuron-specific enolase, and somatostatin, and endocrine-type granules were found ultrastructurally. This type of adenocarcinoma is considered to have a histogenesis similar to that of pulmonary blastoma. To our knowledge this is the first reported case in the cytologic literature.     

Laryngeal blastoma. A light and electron microscopic study of a novel entity analogous to pulmonary blastoma

A neoplasm morphologically analogous to pulmonary blastoma, but arising in the pyriform fossa of the larynx, is described and illustrated. The patient, a 65-year-old white man, was treated with laryngectomy and is alive and free of disease 13 months later. Grossly polypoid on a broad stalk, the neoplasm consisted of a mixture of blastematous, mesenchymal, and epithelial elements. Ultrastructural examination showed that the spindle and stellate cells were truly mesenchymal. The name "laryngeal blastoma" is proposed for this novel entity.     

Classic biphasic pulmonary blastoma with brain and axillary metastases: a case report with molecular analysis and review of literature

Pulmonary blastoma is a rare series of malignant lung tumor, which contains three categories: classic biphasic pulmonary blastoma, pluropulmonary blastoma, and well-differentiated fetal adenocarcinoma. In this study, a 19-year old female suffering with classic biphasic pulmonary blastoma and metastases in brain and axilla was presented with special interest in clinicopathological presentations, immunohistochemical features, and molecular characterizations. However, this case was misdiagnosed initially with small biopsy specimen. Comprehensive management should be used for the treatment of this malignancy.     

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. 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.     

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.     

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.     

Combined small cell carcinoma with pulmonary blastoma and adenocarcinoma: case report and clonality analysis

We describe a rare tumor occurring in the left pulmonary lobe of a 71-year-old Japanese man. The tumor, which was resected by left lower lobectomy, measured 65×50×50 mm. Histologic examination revealed papillary adenocarcinoma in small cell carcinoma, and chondrosarcoma. Also, the blastemal cells were located between the small cell carcinoma and the chondrosarcoma, and intermingled with both components. In blastemal cells, some glands resembled a well-differentiated fetal adenocarcinoma. The tumor was diagnosed as combined small cell carcinoma with pulmonary blastoma and papillary adenocarcinoma according to the 2004 WHO classification. Immunohistochemically, the small cell carcinoma expressed TTF-1, pancytokeratin, CD56, synaptophysin, and S100 protein, while blastemal cells expressed vimentin, desmin, smooth muscle actin, CD56, and S100 protein. To investigate whether the tumor was clonal or not, p53 gene mutation of each tumor component was analyzed by laser-captured microdissection, polymerase chain reaction-single-strand conformation polymorphism and direct sequencing. Despite the histologic complexity, all components showed the same mutation at exon5 of the p53 gene. These results indicate that the tumor was clonal and arose from a relatively primitive cell, and that p53 mutation occurred before histologic metamorphosis or differentiation.     

Malignant biphasic tumors of the lungs

Malignant biphasic tumors of the lungs are rare primary tumors of the bronchopulmonary system. These tumors are composed of malignant epithelial and mesenchymal elements and together comprise <2% of all primary pulmonary neoplasms. The tumors belonging to this group include pulmonary blastoma, pleuropulmonary blastoma, and carcinosarcoma. In this study, the clinicopathologic features, immunohistochemical phenotype, molecular biological characteristics, and the differential diagnosis of these uncommon neoplasms are discussed.     

Nasal Blastoma: A Light and Electron Microscopic Study

The first light and electron microscopic study of a nasal blastoma is reported. Analogous to a pulmonary blastoma, the tumor is composed of well-differentiated squamous and glandular epithelial elements surrounded by a spindle cell stroma. The spindle stromal cell is a myofibroblast. Eighteen months after complete surgical removal of the tumor and radiation therapy, the patient is clinically free of disease.     

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.     

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.     

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.     

An unusual embryonal tumor of the nasal cavity in a neonate--a nasal blastoma? A clinical, histologic, and ultrastructural study

We report the clinicopathological and ultrastructural features of a primitive embryonal tumor which occurred as a polypoid mass in the nasal cavity of a newborn infant. Its primitive-appearing, glycogen-rich, small round cells exhibited epithelial characteristics histologically, immunohistochemically, and ultrastructurally. The tumor was initially diagnosed as embryonal carcinoma because of evidence for endodermal differentiation and lack of specific features of other types of small round cell tumors of childhood. However, it did not have the characteristic features of endodermal sinus tumor nor the anaplasia of the adult type of embryonal carcinoma. It had some resemblance to embryonic somatic tissues and the blastemal component of some of the primitive tumors of childhood. Because of its unique morphological appearance, which has never been reported, and its relatively indolent behavior after chemotherapy and radiotherapy, we believe that this is a distinctive primitive teratoid tumor which may be classified as nasal blastoma.