p53 and K-ras mutational genotyping in pulmonary carcinosarcoma, spindle cell carcinoma, and pulmonary blastoma: implications for histogenesis

Novel model for cancer-specific survival of patients with pulmonary sarcomatoid carcinoma: A population-based analysis and external validation

BACKGROUND/OBJECTIVE

We aimed to develop a comprehensive and effective nomogram for predicting cancer-specific survival (CSS) in patients with pulmonary sarcomatoid carcinoma (PSC).

METHODS

Data for patients diagnosed with PSC between 2004 and 2018 from the Surveillance, Epidemiology, and End Results database were retrospectively collected and randomly divided into training and internal validation sets. We then retrospectively recruited patients diagnosed with PSC to construct an external validation cohort from the Southwest Hospital. A prognostic nomogram for CSS was established using independent prognostic factors that were screened from the multivariate Cox regression analysis. The performance of the nomogram was evaluated using area under the receiver operating characteristic (ROC) curves, Harrell's concordance index (C-index), calibration diagrams, and decision curve analysis (DCA). The clinical value of the nomogram and tumor, nodes, and metastases (TNM) staging system was compared using the C-index and net reclassification index (NRI).

RESULTS

Overall, 1356 patients with PSC were enrolled, including 876, 377, and 103 in the training, internal validation, and external validation sets, respectively. The C-index and ROC curves, calibration, and DCA demonstrated satisfactory nomogram performance for CSS in patients with PSC. In addition, the C-index and NRI of the nomogram suggested a significantly higher nomogram value than that of the TNM staging system. Subsequently, a web-based predictor was developed to help clinicians obtain this model easily.

CONCLUSIONS

The prognostic nomogram developed in this study can conveniently and precisely estimate the prognosis of patients with PSC and individualize treatment, thereby assisting clinicians in their shared decision-making with patients.

Epstein-Barr virus-associated leiomyosarcoma of the larynx in an adult patient with human immunodeficiency virus infection: Case report and review of the literature

We investigated the clinical features, treatment, and prognosis of laryngeal leiomyosarcoma (LLMS) and Epstein-Barr virus-associated (EBV-associated) LMS. We report a case of EBV-associated LLMS in an adult patient with HIV infection. We also conducted a review of the English-language literature on LLMS and EBV-associated leiomyosarcoma. To the best of our knowledge, 62 cases of LLMS and EBV-associated leiomyosarcoma have been reported to date. Of patients with LLS, 18.9% had distant metastases and 17.0% had local recurrence. The overall 5-year survival rate was 64.0%. Distant metastases affected the survival of patients with LLMS (p = 0.04). EBV-positive patients had a low survival rate (p = 0.01). Among patients with EBV-associated LMS, 8.2% had distant metastases and recurrence and the overall 5-year survival rate was 50.0%. EBV-associated LLMS is rare. The EBV infection might be a poor prognostic factor of LLMS.

Clinicopathological and Prognostic Features of 67 Cases with Pulmonary Sarcomatoid Carcinoma: An 18-Year Single-Centre Experience

INTRODUCTION

Pulmonary sarcomatoid carcinoma (PSC) is a very rare subtype of non-small-cell lung cancer (NSCLC). It is frequently diagnosed in the advanced stage and is resistant to conventional chemotherapeutics. Due to the unique nature and rarity, we evaluated the epidemiological, clinicopathological, and survival data of PSC patients treated at our centre.

PATIENTS AND METHODS

We retrospectively collected demographic and clinical data of 67 PSC patients from a single tertiary referral hospital, between the 2000 and 2018. Univariate and multivariate analyses were performed to determine the risk factors affecting survival.

RESULTS

The median age was 61 years, and the percentage of male was 74.6%. Most of the patients had a smoking history (76.9%). The most common PSC subtype was pleomorphic carcinoma (46.3%). The median overall survival (OS) was 55.4 months, and the 5-year OS rate was 47.5%. Advanced stage, T4 tumour, and positive lymph node involvement were associated with poor OS (p < 0.05). The patients with negative epithelial markers had poorer prognosis (p = 0.027) and had more frequently stage IV disease (p = 0.016). Surgical treatment and stage IV disease were determined to be independent prognostic factors.

CONCLUSION

PSC is an extremely rare and aggressive variant of NSCLC. Positive epithelial markers may have favourable prognostic significance in PSC. Resection of the tumour with a negative surgical margin is crucial for better survival. The prognosis of the disease is very poor in the metastatic stage.

A Rare case of Classic Biphasic Pulmonary Blastoma

Biphasic pulmonary blastomas are rare tumors that together with pulmonary carcinosarcomas comprise less than 2 per cent of all lung neoplasms. They can be defined as tumors that are composed of an admixture of immature mesenchyme and epithelium and that recapitulate morphologically the embryonal structure of the lung. First described in 1945 by Barnett and Barnard, their existence is well documented although their occurrence is rare. We present a case of a 40-year-old Hispanic female that presented with a 2-month history of retrosternal and midepigastric pain. A GI etiology was initially treated unsuccessfully with antireflux medications. A chest radiograph showed a 4.6-cm mass in the right upper lobe of the lung, and computed tomography showed right apical bullous formation with no lymphadenopathy. Bronchoscopy revealed no endobronchial lesions, and biopsy was nondiagnostic. The histopathologic and immunophenotypic analysis of a right upper lobectomy specimen was diagnostic of classic biphasic pulmonary blastoma. The rarity of these tumors makes easy identification difficult. Immunohistochemical analysis must be used to arrive at the proper diagnosis. It is imperative that there be good communication between the surgeon and pathologist and that institutions have access to facilities with the ability of identifying these complex tumors.

The characteristic of tumor immune microenvironment in pulmonary carcinosarcoma

Pulmonary carcinosarcoma (PCS) is a rare but aggressive neoplasm, due to late diagnosis and early metastasis. Surgery combined with radiotherapy is a standard treatment. However, PCS features an easy relapse after surgery resection and resistance to chemotherapy and radiotherapy. Tumor immune microenvironment reflects tumor immunophenotyping and affects immunotherapy efficiency. This review summarized current studies on the characteristic of tumor immune microenvironment in PCS and discussed the potential of immunotherapy combined with other regimes strategy as a candidate for treatments in PCS.

Clinicopathologic features and genomic analysis of pulmonary blastomatoid carcinosarcoma

BACKGROUND

This study was designed to investigate the clinicopathologic features of pulmonary blastomatoid carcinosarcoma and explore the genomic profiles of epithelial and mesenchymal components in this tumor.

METHODS

Three cases of pulmonary blastomatoid carcinosarcoma were enrolled in this study. Clinicopathologic information and prognostic data were retrospectively reviewed. Diagnostic immunohistochemistry was performed. The epithelial and mesenchymal components were microdissected to investigate the genomic profiles by performing capture-based targeted next generation sequencing.

RESULTS

The epithelial components in patient one consisted of low-grade and high-grade fetal lung adenocarcinoma. Low-grade epithelial cells showed nuclear expression of β-catenin and missense mutation of CTNNB1. The epithelial components in another two patients consisted of high-grade fetal lung adenocarcinoma/enteric adenocarcinoma. The epithelial cells showed membrane staining of β-catenin and harbored no mutation of CTNNB1. The mesenchymal components in all three tumors were composed of primitive round/spindle cells without definite differentiation and showed cytoplasmic dot positive of β-catenin and no corresponding mutation. Within a tumor, both components exhibited relatively comparable molecular profile. In patient one, 4 mutations: RB1, FAT3, PTCH1 and LRP1B were shared by both epithelial and mesenchymal components. Epithelial component had additional mutations in BCOR, CTNNB1, CTCF, FAT1 and DICER1. In patient two, 12 mutations were shared. The epithelial component had BRCA2 mutation and the mesenchymal had mutations in CREBBP, ALK, DNMT3A, ASXL2, MYCN and RICTOR. Patient three had 6 shared mutations. The epithelial component had an additional mutation in KAT6A and the mesenchymal had an additional mutation in APC. Collectively, we observed heterogeneity between epithelial and mesenchymal components of the same tumor.

CONCLUSIONS

Blastomatoid carcinosarcoma showed characteristic morphology and immunophenotype. Parallel detection of genetic abnormalities in epithelial and mesenchymal components could provide further evidence for tumor differentiation, molecular targeting and differential diagnosis.

The EMT transcription factor, Twist1, as a novel therapeutic target for pulmonary sarcomatoid carcinomas

Pulmonary sarcomatoid carcinomas (PSCs) are a rare subtype of non‑small‑cell lung cancer and are typically biphasic neoplasms. No effective treatment for PSCs is currently available in clinical practice. The expression of the epithelial‑mesenchymal transition (EMT) transcription factors, Twist1, Slug and Snail, as well as the EMT phenotype and vasculogenic mimicry (VM) were analysed in 41 PSC and 79 pulmonary squamous carcinoma (PSCC) samples. Compared with the PSCCs, the PSCs exhibited an EMT phenotype and VM, and they also exhibited an increased expression of the Twist1, Slug, Snail and VM markers. Twist1 expression was associated with metastasis and TNM stage. Twist1‑positive patients exhibited a poorer prognosis for overall survival (OS) than those with Twist1‑negative PSCs. Transforming growth factor β1 (TGFβ1) was used to induce an EMT transition in a PSCC cell line. SK‑MES‑1 cells treated with TGFβ1 exhibited an increased expression of Twist1. The EMT phenotype, VM and increased migratory and invasive abilities were induced following TGFβ1 treatment. Importantly, in cells treated with TGFβ1, the EMT phenotype was reversed, VM marker expression was decreased, and the migratory and invasive ability of the PSCC cell line was decreased following Twist1 knockdown. Collectively, this study provides a new perspective of Twist1 in the aggressiveness of PSCs. The identification of Twist1 as an independent marker of poor prognoses may lead to the development of novel strategies for improving the treatment of patients with PSC.

Approaches to Tumor Classification in Pulmonary Sarcomatoid Carcinoma

Pulmonary sarcomatoid carcinoma (PSC) is a heterogeneous category of primary lung cancer accounting from 0.3% to 3% of all primary lung malignancies. According to the most recent 2015 World Health Organization (WHO) classification, PSC includes several different variants of malignant epithelial tumors (carcinomas) histologically mimicking sarcomas showing or entirely lacking a conventional component of non-small cell lung cancer (NSCLC). Thus, this rare subheading of lung neoplasms includes pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, pulmonary blastoma, and carcinosarcoma. A diagnosis of PSC may be suspected on small biopsy or cytology, but commonly requires a surgical resection to reach a conclusive definition. The majority of patients with PSC consists of elderly, smoking men with a large, peripheral mass characterized by well-defined margins. However, presentation with a central, polypoid endobronchial lesion is well-documented, particularly in pleomorphic carcinoma and carcinosarcoma showing a squamous cell carcinoma component. As expected, PSC may pose diagnostic problems and immunohistochemistry is largely used when pathologists deal these tumors in routine practice. Indeed, PSC tends to overexpress molecules associated with the epithelial-to-mesenchymal transition, such as vimentin, but the panel of immunostains also includes epithelial markers (cytokeratins, EMA), TTF-1, p40 and negative markers (e.g., melanocytic, mesothelial and sarcoma-related primary antibodies). Although rare, PSC has increased their interest among oncologist community for different reasons: a. identification of the epithelial-to-mesenchymal phenomenon as a major mechanism of secondary resistance to tyrosine kinase inhibitors; b. over-expression of PD-L1 and effective treatment with immunotherapy; c. identification of c-MET exon 14 skipping mutation representing an effective target to crizotinib and other specific inhibitors. In this review, the feasibility of the diagnosis of PSC, its differential diagnosis and novel molecular findings characterizing this group of lung tumor are discussed.

Pulmonary Sarcomatoid Carcinomas: A Review

Pulmonary sarcomatoid carcinomas belong to a group of neoplasms that remain incompletely understood. They are rare tumors of the bronchopulmonary system that incorporate a wide range of neoplasms that by definition contain a sarcomatoid component characterized by spindle or giant cells. Such classification has led to a heterogenous tumor category that includes neoplasms with different clinical, morphologic, and prognostic features. To date, the histopathologic diagnosis of pulmonary sarcomatoid carcinomas does not require the use of ancillary testing and is based on light microscopic criteria alone. However, with recent advances in immunohistochemical and molecular methods, it is becoming increasingly clear that pulmonary sarcomatoid carcinomas represent poorly differentiated or "dedifferentiated" variants of conventional non-small cell carcinomas with similar immunophenotype and molecular signatures. This review summarizes the latest insights and concepts of these unusual tumors and outlines future directions with emphasis on tumor classification and patient management.

Immunohistochemical analysis of NANOG expression and epithelial-mesenchymal transition in pulmonary sarcomatoid carcinoma

Pulmonary sarcomatoid carcinomas (PSCs) are defined as a group of poorly differentiated non-small cell lung cancers that demonstrate sarcoma-like differentiation. The mechanism of mesenchymal differentiation in PSC is epithelial-mesenchymal transition (EMT). The expression of homeobox protein NANOG (NANOG), which regulates the pluripotency of embryonic stem cells, is associated with the EMT process. Therefore, the present study aimed to assess the expression level of NANOG and the status of the EMT process in PSC. The data of patients with PSC were retrospectively reviewed and immunohistochemical analyses were performed on patient samples to examine the expression of NANOG and EMT-associated proteins. The comparator group included randomly selected patients with matched clinicopathological characteristics who had pulmonary adenocarcinoma (PA). In the present study, 12 patients with PSC (4 females and 8 males) were enrolled; their median age was 65 years (range, 36-79 years), and the number of patients with stage IB, IIB, IIIA, IIIB and IV disease were 1, 1, 1, 1 and 8, respectively. The immunoreactive score (IRS) for E-cadherin was significantly lower in the PSC group compared with the PA group (P<0.0001), whereas the IRS for vimentin was significantly higher in the PSC group compared with the PA group (P<0.0001). However, the IRS for NANOG was significantly decreased in the PSC group compared with the PA group (P<0.0001), which suggests that NANOG does not serve an essential role in EMT in PSC. In addition, the overall survival of patients with PSC was significantly lower compared with that of patients with PA (median survival time, 7.0 vs. 35.6 months, respectively; P=0.0256). However, no significant difference was observed in the OS of patients who expressed low compared with high levels of NANOG (P=0.4416). In conclusion, it was clearly demonstrated that cytoplasmic NANOG expression was significantly lower in PSC compared with PA, and that the EMT process in PSC was accelerated, compared with that in PA.

The 2015 World Health Organization Classification of Lung Tumors: Impact of Genetic, Clinical and Radiologic Advances Since the 2004 Classification. J Thorac Oncol. 2015;10:1243-1260. [PMID: 26291008 DOI: 10.1097/jto.0000000000000630]

The 2015 World Health Organization (WHO) Classification of Tumors of the Lung, Pleura, Thymus and Heart has just been published with numerous important changes from the 2004 WHO classification. The most significant changes in this edition involve (1) use of immunohistochemistry throughout the classification, (2) a new emphasis on genetic studies, in particular, integration of molecular testing to help personalize treatment strategies for advanced lung cancer patients, (3) a new classification for small biopsies and cytology similar to that proposed in the 2011 Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification, (4) a completely different approach to lung adenocarcinoma as proposed by the 2011 Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification, (5) restricting the diagnosis of large cell carcinoma only to resected tumors that lack any clear morphologic or immunohistochemical differentiation with reclassification of the remaining former large cell carcinoma subtypes into different categories, (6) reclassifying squamous cell carcinomas into keratinizing, nonkeratinizing, and basaloid subtypes with the nonkeratinizing tumors requiring immunohistochemistry proof of squamous differentiation, (7) grouping of neuroendocrine tumors together in one category, (8) adding NUT carcinoma, (9) changing the term sclerosing hemangioma to sclerosing pneumocytoma, (10) changing the name hamartoma to "pulmonary hamartoma," (11) creating a group of PEComatous tumors that include (a) lymphangioleiomyomatosis, (b) PEComa, benign (with clear cell tumor as a variant) and

Wide expression of ZEB1 in sarcomatous component of spindle cell carcinoma of the esophagus

The pathogenesis of sarcomatous component in spindle cell carcinoma (SpCC) of the esophagus is unclear. To investigate the involvement of epithelial-mesenchymal transition (EMT) in sarcomatous differentiation, we performed immunohistochemistry for Slug, Twist, ZEB1, and ZEB2, transcription factors associated with EMT and E-cadherin, in 14 cases of SpCC of the esophagus. In order to verify the neoplastic nature of sarcomatous components, TP53 mutation status and protein expression were examined in each case. Nuclear ZEB1 expression was extensive in the sarcomatous component, greater than invasive front of carcinoma components (P < 0.0001). Membranous E-cadherin expression was mostly lost in sarcomatous cells in all cases (P < 0.0001). The p53 expression pattern was almost concordant between the two areas in all cases. TP53 mutation analysis revealed that seven cases harbored identical mutations in both components. One case had mutations only in the sarcomatous component. It is noteworthy that none of them harbored mutation in exon 5, unlike conventional esophageal squamous cell carcinoma. These findings show that ZEB1 are widely expressed in the sarcomatous area of SpCC of the esophagus, suggesting the involvement of EMT. The avoidance of exon 5 in terms of TP53 mutation may also be a feature of the tumor.

[Sarcomatoid carcinoma of the lung: retrospective study of 28 cases]

INTRODUCTION

Sarcomatoid carcinoma (SC) of the lung is defined by the World Health Organization as poorly differentiated non-small cell carcinoma that contains a component of sarcoma or sarcoma-like elements. It represents an overall continuum of epithelial and mesenchymal differentiation. Five subtypes are recognized: pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. The diagnosis is pathological and requires a good sampling of the tumor.

PATIENTS AND METHODS

Twenty-eight cases of primary sarcomatoid carcinoma, diagnosed between 1993 and 2010, were reviewed retrospectively, noting the clinicopathological characteristics.

RESULTS

The patient population consisted of 25 males and 3 females with mean age of 62.9 years (48-75 years). The symptomatology was dominated by respiratory symptoms. Imaging features showed a pulmonary mass invading pleura or thoracic wall in 5 cases. The diagnosis was made in all cases on histological examination. These 28 tumors were divided as below: into 19 pleomorphic carcinomas, 4 giant cell carcinomas, 1 spindle cell carcinoma and 4 carcinosarcomas. Twenty-seven tumors were treated surgically. Associated treatments were neoadjuvant (3 cases) or adjuvant chemotherapy (1 case) and preoperative radiotherapy (5 cases). Deaths occurred in 7 patients. Twenty-two patients were lost to follow up.

CONCLUSION

These tumors are frequently symptomatic, are locally advanced, and have higher rates of recurrence. Its prognosis is worse than that of other non-small cell lung cancer.

A rare association of leiomyosarcoma with squamous cell carcinoma of the larynx: two cases

OBJECTIVE

To discuss the histopathogenesis and treatment choices for synchronous tumours of the larynx.

CASE REPORTS

We present two cases of synchronous laryngeal leiomyosarcoma and squamous cell carcinoma. The first case was an early-stage tumour and the second an advanced-stage tumour of the larynx. Selection of adequate treatment for synchronous tumours is difficult because of different spreading rates and metastatic patterns. Treatment choices for both the primary tumour site and the neck should be related to the stage of the squamous component of the tumour.

CONCLUSION

In such cases, the tumour location, tumour stage and lymphatic metastases must be carefully evaluated in order to make the optimum treatment choice. Treatment evaluation of the neck should be related to the stage of the squamous component of these synchronous tumours. Partial laryngectomy techniques may be preferred if the extent of the disease permits.

Multiparametric molecular characterization of pulmonary sarcomatoid carcinoma reveals a nonrandom amplification of anaplastic lymphoma kinase (ALK) gene

BACKGROUND

Genetic alterations for targeting therapy are largely unexplored issues in pulmonary sarcomatoid carcinoma (PSC), a life-threatening tumor subset.

METHODS

EGFR, HER2, KRAS, p53, CTNNB1, BRAF and PIK3CA mutations were assessed by direct sequencing, ALK, EGFR and HER2 gene status by fluorescence in situ hybridization (FISH), and ALK protein expression by immunohistochemistry (IHC) in 20 pleomorphic carcinomas (PLC), two pulmonary blastomas (PB) and one carcinosarcoma (CS). Surgical specimens and, in case of positivity, the corresponding preoperative biopsies were analyzed. Furthermore, 51 consecutive metastatic lung adenocarcinomas (MELAD) were used as controls for FISH and IHC assays of ALK gene.

RESULTS

While no rearrangements of ALK were detected in PSC, relevant amplification was identified 5/23 (22%) surgical specimens and paired biopsies (four PLC and one PB, two females and three males, four current and one never smoker, aged 30-83 years). Considering tumor heterogeneity, the percentage of ALK amplified tumor cells ranged from 11% to 43%, with a mean gene copy gain (GCG ± SD) of 6.9 ± 0.8 and no signal differences between the epithelial (6.5 ± 0.9) and the sarcoma-like components (6.8 ± 0.9) of tumors. In the remaining 18 non-amplified PSC, the relevant value was 2.9 ± 0.5 in 1-80% tumor cells (p<0.001). ALK amplification was closely associated with chromosome 7 (EGFR) or 17 (HER2) polysomy (p<0.001). Out of 51 MELAD, 10 were ALK-rearranged (p=0.026) and only one amplified (p=0.009). No amplified tumors, either PSC or MELAD, expressed the relevant protein by IHC, while the 10 ALK-rearranged MELAD were strongly positive. TP53, KRAS and CTNNB1 mutations accounted for 30%, 22%, and 4% of cases, respectively, with no significant relationship with ALK amplification. No mutations for EGFR, HER2, BRAF or PIK3CA gene were observed.

CONCLUSION

ALK gene amplification is a nonrandom and clonally related event in a subset of PSC, but its biologic rationale deserves further investigation. KRAS mutation could represent a novel tool for therapy of such so deadly tumors with MEK inhibitors.

Expression and mutation analysis of EGFR, c-KIT, and β-catenin in pulmonary blastoma

Introduction

Pulmonary blastoma (PB) is a rare malignant lung tumour with an immature mesenchymal and epithelial component resembling fetal lung. In order to define potential therapeutic targets in PB, the authors analysed the status and possible role of EGFR, HER2 and c-KIT in the pathogenesis of this tumour type, and the diagnostic value of β-catenin mutation analysis in PB.

Methods

5 PBs were analysed for EGFR, HER2, c-KIT, and β-catenin expression, as well as for mutations in EGFR, c-KIT, k-ras and the β-catenin gene (CTNNB1).

Results

EGFR expression was observed in all PBs. An EGFR mutation was found in one of the tumours. No overexpression of c-KIT or HER2 was seen. No mutations were found in k-ras or c-KIT. 3 of 5 PBs displayed CTNNB1 mutations. Nuclear translocation of β-catenin was seen in 2 of these tumours.

Conclusions

Detection of EGFR expression and mutation in PB suggest EGFR inhibition as a potential therapeutic option in the treatment of advanced PB. Moreover, the data confirm a crucial role of CTNNB1 mutations in the pathogenesis of PB, and indicate that CTNNB1 gene sequencing may be a useful in distinguishing PB from other types of lung cancer.

Sarcomatoid neoplasms of the lung and pleura

Sarcomatoid neoplasms of the lung and pleura are rare tumors that present a complex differential diagnosis, making them challenging for surgical pathologists. In the lung, the main tumors are the sarcomatoid carcinomas, including pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. They are characterized by histologic heterogeneity; molecular data support their origin from a pluripotent stem cell that undergoes neoplastic transformation with divergent epithelial and sarcomatous differentiation. Diagnosis is difficult in small biopsy specimens and typically requires a resection specimen. Despite the presence of sarcomatoid features, these tumors are classified as lung carcinomas. Pulmonary blastomas must be distinguished from pleuropulmonary blastomas, which are a unique type of thoracic sarcoma typically occurring in young children. In the pleura, the main tumors to consider are the sarcomatoid and desmoplastic types of malignant mesothelioma, solitary fibrous tumor, and desmoid tumor. While light microscopy is sufficient to diagnose most of these tumors, immunohistochemistry can be useful in selected settings. In particular, it can aid to confirm epithelial differentiation in spindle cell carcinomas and the presence of rhabdomyosarcoma in sarcomatoid carcinomas, mesotheliomas, or pleuropulmonary blastomas. For sarcomatoid and desmoplastic mesothelioma, keratin is the most useful stain because it can highlight invasive growth and mesothelial markers are positive in only the minority of cases. Clinical and radiologic correlation is needed to separate some pleomorphic carcinomas with pleural involvement from sarcomatoid malignant mesothelioma, since these poorly differentiated tumors may not express the usual immunohistochemical markers for carcinoma or mesothelioma.

Malignant mixed Mullerian tumors of the uterus: histopathological evaluation of cell cycle and apoptotic regulatory proteins

Aim

The aim of our study was to evaluate survival outcomes in malignant mixed Mullerian tumors (MMMT) of the uterus with respect to the role of cell cycle and apoptotic regulatory proteins in the carcinomatous and sarcomatous components.

Methods

23 cases of uterine MMMT identified from the Saskatchewan Cancer Agency (1970-1999) were evaluated. Immunohistochemical expression of Bad, Mcl-1, bcl-x, bak, mdm2, bax, p16, p21, p53, p27, EMA, Bcl-2, Ki67 and PCNA was correlated with clinico-pathological data including survival outcomes.

Results

Histopathological examination confirmed malignant epithelial component with homologous (12 cases) and heterologous (11 cases) sarcomatous elements. P53 was strongly expressed (70-95%) in 15 cases and negative in 5 cases. The average survival in the p53+ve cases was 3.56 years as opposed to 8.94 years in p53-ve cases. Overexpression of p16 and Mcl-1 were observed in patients with longer survival outcomes (> 2 years). P16 and p21 were overexpressed in the carcinomatous and sarcomatous elements respectively. Cyclin-D1 was focally expressed only in the carcinomatous elements.

Conclusions

Our study supports that a) cell cycle and apoptotic regulatory protein dysregulation is an important pathway for tumorigenesis and b) p53 is an important immunoprognostic marker in MMMT of the uterus.

Pulmonary carcinosarcoma initially presenting as invasive aspergillosis: a case report of previously unreported combination

Carcinosarcoma of the lung is a malignant tumor composed of a mixture of carcinoma and sarcoma elements. The carcinomatous component is most commonly squamous followed by adenocarcinoma. The sarcomatous component commonly comprises the bulk of the tumor and shows poorly differentiated spindle cell features. Foci of differentiated sarcomatous elements such as chondrosarcoma and osteosarcoma may be seen. Aspergillus pneumonia is the most common form of invasive aspergillosis and occurs mainly in patients with malignancy, immunocompromising or debilitating diseases. Patients with Aspergillus pneumonia present with fever, cough, chest pain and occasionally hemoptysis. Tissue examination is the most reliable method for diagnosis, and mortality rate is high.We describe a case of primary carcinosarcoma of the lung concurrently occurring with invasive pulmonary aspergillosis in a 66-year old patient.

Review article: pulmonary sarcomatoid carcinomas: a practical overview

Pulmonary sarcomatoid carcinomas (PSCs) are currently defined as poorly differentiated non-small-cell carcinomas containing a component with sarcoma or sarcoma-like (spindle and/or giant cell) features. They consist of 5 major histological variants, namely pleomorphic carcinoma, spindle cell carcinoma, giant cell carcinoma, carcinosarcoma, and pulmonary blastoma. The segregation of PSCs into a distinct clinicopathologic entity seems justified on the basis of morphologic, behavioral, and genotypic/phenotypic attributes. As a group, PSCs generally run an aggressive clinical course and may cause major difficulties in the differential diagnosis with other primary and secondary malignancies of the lung. At present, PSCs are believed to represent a family of carcinomas "in transition," in which diverse pathways of clonal evolution account for histological differences of a common ancestor lesion. The sarcomatous or sarcomatoid component of these tumors is thought to derive from carcinoma cells during the progression of carcinogenesis through the activation of an epithelial-mesenchymal transition program leading to sarcomatous transformation or metaplasia (conversion paradigm). Conceivably, targeting the epithelial-mesenchymal transition program could become a valid therapeutic strategy for these life-threatening tumors, whose sensitivity to current medical manipulation is disappointing.

Biphasic pulmonary blastoma with germ cell differentiation in a 36-year-old man

We describe the clinical and pathologic findings of a young man with a heterogeneous mediastinal tumor metastatic to both lungs, and containing a predominant pattern of classic biphasic pulmonary blastoma with elements of immature teratoma, seminoma, and embryonal carcinoma. Beta-human chorionic gonadotropin and alpha-fetoprotein were elevated at presentation and responded to four cycles of bleomycin, etoposide, and cisplatin although the tumor did not regress. The patient ultimately progressed through paclitaxel, ifosfamide, and cisplatin and tandem autologous bone marrow transplants. Classic biphasic pulmonary blastoma is a rare tumor of young adults. Surgery is the primary treatment, but prognosis is poor and chemotherapy and radiation have been used for unresectable disease. A discussion of pulmonary blastoma and extragonadal germ cell tumors is presented.

Clonality and heterogeneity of pulmonary blastoma from the viewpoint of genetic alterations: A case report

Biphasic pulmonary blastoma is a rare lung tumor with epithelial and mesenchymal components. Genetic alterations in this tumor are largely unknown, except for the presence of beta-catenin and p53 mutations and the absence of KRAS mutation. To understand the molecular process of histogenesis of this tumor, a whole genome allelic imbalance (AI) scanning using a high-resolution single nucleotide polymorphism array as well as mutational analysis of the p53, EGFR, KRAS and beta-catenin genes were performed against the epithelial and mesenchymal components in the primary tumor and a metastatic tumor in a case of pulmonary blastoma. AI at chromosome regions 14q24-q32 and 17p11-p13 and beta-catenin mutation were commonly detected in all tumors. On the other hand, AI at chromosome regions 3p11-p14 and 9p21-p24 and p53 mutation were detected only in the mesenchymal component in the primary tumor but not in the epithelial component in the primary tumor and the brain metastasis. Likewise, AI at chromosome regions 6p24-p25 and 6q14-q27 was detected in the epithelial component in the primary tumor and the brain metastasis but not in the mesenchymal component in the primary tumor. Furthermore, the genetic alterations detected in the metastatic tumor were completely the same as those in the epithelial component in the primary tumor, indicating that a tumor cell(s) in the epithelial component in the primary tumor selectively metastasized to the brain. These results indicate that this biphasic tumor is of monoclonal origin and the phenotypic heterogeneity of the tumor is due to the differences in the accumulated genetic alterations in each component of the tumor.

Sarcomatoid carcinomas of the lung—are these histogenetically heterogeneous tumors?

Sarcomatoid carcinomas (SC) of the lung are a heterogeneous group of nonsmall cell lung carcinomas (NSCLC) containing a sarcoma or sarcoma-like component. SC may represent an epithelial neoplasm undergoing divergent tissue differentiation originating from a single clone. Epithelial-mesenchymal transition (EMT) best describes the origin of the spindle and giant cells. We aimed to define chromosomal aberrations within the subgroups of SC and if EMT does play a role in SC. Twenty-two SC were investigated by chromosomal comparative genomic hybridization (CGH). Immunohistochemical staining was performed with antibodies for E-cadherin, Vimentin, c-Fos, c-Jun, Snail, TGFbeta1, Notch1, beta-catenin, Glycogen synthase kinase 3beta (GSK3beta), and Fascin. Gains occurred more frequently than losses (70.5 vs 29.5%). The shortest regions of overlap were gains on chromosomes 8q and 7 followed by 1q, 3q, and 19, supporting the common origin of the different subtypes of SC. The immunohistochemical staining suggests that the sarcomatoid components of SC might have undergone EMT, not triggered by the signaling pathways Notch1, Snail, and TGFbeta1, but probably initiated by an upregulation of c-Jun and a consecutive overexpression of Vimentin and Fascin. The Wnt-pathway was not deregulated because combined membrane and cytoplasmic reactivity for beta-catenin and GSK3beta was observed.

Expression of CD99 in pleomorphic carcinomas of the lung

Pleomorphic carcinoma of the lung (PCL) is characterized by a mixture of sarcomatoid and carcinoma components, and a poor prognosis. However, no immunophenotype of tumor markers has been characterized in PCL. To characterize the immunophenotype for CD99 in PCL, we performed an immunohistochemical evaluation of PCLs for thyroid transcription factor-1 (TTF-1), cytokeratin (CK) 7 and 20, and for CD99. CD99 was found to be expressed in both carcinomatous (47%) and sarcomatous components such as spindle cells (92%) and giant cells (57%). In the case of spindle cells, CK7 was expressed in 6 cases (46%) and TTF-1 in 2 cases (15%), whereas for giant cells CK7 was expressed in 8 cases (57%) and TTF-1 in one case (7%). However, CK20 was not expressed in either the carcinomatous or sarcomatous components in any case. Thus, CD99 was found to be widely expressed in both sarcomatous and carcinoma component in PCL. A clinicopathological analysis showed no direct correlation between the expression of CD99 and the clinical indices (stage, survival rate, invasion) of PCL.

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.

K-ras gene mutational analysis supports a monoclonal origin of biphasic pleomorphic carcinoma of the lung

We investigated 27 pleomorphic carcinomas of the lung for exon 1 K-ras gene mutations using polymerase chain reaction-single-strand conformation polymophism analysis and direct sequencing. All pleomorphic carcinomas were biphasic, that is, composed of an adeno-, squamous- or large-cell-carcinomatous component associated with a spindle- and/or giant-cell component. Of 27 cases, six (22%) showed K-ras codon 12 mutations, which is a figure higher than that previously reported on in pure sarcoma-like pleomorphic carcinomas. Five tumors displayed the same mutation in both the epithelial and the sarcomatoid components, whereas in one tumor the mutation was restricted to the epithelial component. All mutations occurred in smokers, and were transversions, including GGT (glycine) to TGT (cysteine) change in two cases, to GCT (alanine) in two and to GTT (valine) in two. No significant relationships were found between the occurrence and type of mutations and patients' survival or any other clinicopathological variable, suggesting that K-ras mutations are early events in the development of these tumors. Our results indicate that most, though not all, biphasic pleomorphic carcinomas of the lung are monoclonal in origin, and that cigarette smoking may have a causative role in the development of K-ras alterations in these tumors, as all mutations are transversions.

Expression of KIT (CD117) in biphasic pulmonary blastoma. Novel data on histogenesis

Biphasic pulmonary blastoma (BPB) is a rare primary neoplasm of the lung and its histogenesis is still uncertain. It has been proposed that BPB is derived from mesoderm or endoderm. Others suggested an origin from a single pluripotential cell. We present a case of a BPB with emphasis on expression of the stem cell factor receptor KIT (CD117). We describe a 61-year-old male patient with a BPB of the upper right lobe. Immunohistochemical analysis was performed using a panel of several antibodies including anti-CD117. Strong cytoplasmic expression of CD117 was found in the epithelium (cytokeratin-positive) as well as in the spindle cells (cytokeratin-negative). Expression of CD117 in both mesenchymal and epithelial cells suggests a single origin and supports the idea that BPB arises from a pluripotential cell that can differentiate into both stromal and epithelial morphologies. The role of CD117 in the pathogenesis of BPB and its possible therapeutic relevance require further investigation.

Pleomorphic carcinomas of the lung show a selective distribution of gene products involved in cell differentiation, cell cycle control, tumor growth, and tumor cell motility: a clinicopathologic and immunohistochemical study of 31 cases

We investigated 31 cases of pleomorphic carcinomas of the lung, with a double component of neoplastic epithelial cells and of spindle and/or giant cells. To correlate the morphologic diversity of these two cell components with their immunophenotype, we evaluated the expression of several gene products involved in cell differentiation (cytokeratins, epithelial membrane antigen, carcinoembryonic antigen, vimentin, S-100 protein, smooth muscle actin, desmin), cell cycle control and apoptosis (p53, p21Waf1, p27Kip1, FHIT), tumor growth (proliferative fraction, assessed by Ki-67 antigen, and microvascular density, assessed by CD34 immunostaining), and tumor cell motility (fascin). We found the epithelial component to be significantly more immunoreactive for cytokeratins, epithelial membrane antigen, carcinoembryonic antigen, cell cycle inhibitors p21Waf1, p27Kip1 and tumor suppressor gene FHIT, whereas the sarcomatoid component, independent of tumor stage and size, was more immunoreactive for vimentin, fascin, and microvascular density. Accordingly, we suggest a model of tumorigenesis whereby the mesenchymal phenotype of pleomorphic cells is likely induced by the selective activation and segregation of several molecules involved in cell differentiation, cell cycle control, and tumor cell growth and motility. Whether pleomorphic carcinomas of the lung are tumors with a dismal prognosis still remains an unsettled issue. In our series, however, stage I pleomorphic carcinomas have the same clinical behavior as ordinary non-small cell lung cancer, and only a high proliferative index (Ki-67 labeling index >35%) is associated with a worse prognosis in these tumors.

Beta-catenin mutations in pulmonary blastomas: association with morule formation

To elucidate the contribution of beta-catenin gene mutation to the development of pulmonary blastomas, we analysed mutations in three well-differentiated fetal adenocarcinomas (WDFAs) and six biphasic pulmonary blastomas (BPBs). For comparison, eight clear-cell adenocarcinomas with fetal lung features were also examined. beta-Catenin gene mutations were found in all three WDFAs, two BPBs, and none of the clear-cell adenocarcinomas with fetal lung features. All tumours with mutations had a common histological feature, namely morule formation, and showed a characteristic heterogeneous beta-catenin expression pattern that was revealed by immunohistochemistry. Strong nuclear/cytoplasmic expression of beta-catenin was seen in clustered cells in the morular areas and in single cells in glands, and was associated with neuroendocrine differentiation. As beta-catenin mutations are rare among lung tumours, this distinctive genetic feature, which is also immunohistochemically detectable as overexpression with a heterogeneous pattern, has diagnostic significance. The presence of this common genetic alteration found in both WDFA and BPB implies a histogenetic linkage between these tumours.

Pulmonary carcinomas with pleomorphic, sarcomatoid, or sarcomatous elements: a clinicopathologic and immunohistochemical study of 75 cases

We collected 75 primary pulmonary carcinomas with pleomorphic, sarcomatoid, or sarcomatous elements to better define their clinical, histologic, and immunohistochemical profile. The patient's age ranged from 42 to 81 years (mean 65 years), and the male-to-female ratio was 9.7:1. Sixty-nine patients (92%) were smokers. Cough and hemoptysis were the most frequent presenting symptoms. Fifty-nine patients (65%) died of disease: only stage significantly predicts overall survival (p = 0.0273). Microscopically, based on the WHO criteria, 58 cases were classified as pleomorphic carcinoma (51 with an epithelial component, 7 composed exclusively of spindle and giant cells), 10 as spindle cell carcinoma, 3 as giant cell carcinoma, 3 as carcinosarcoma, and 1 as pulmonary blastoma. Immunohistochemically, in the tumors composed exclusively of spindle and/or giant cells, thyroid transcription factor-1 (TTF-1) and cytokeratin 7 were positive in 55% and 70% of the cases, respectively, whereas surfactant protein-A was always negative. In pleomorphic carcinomas with an epithelial component, cytokeratin 7, TTF-1, and surfactant protein-A were positive in the sarcomatoid component in 62.7%, 43.1%, and 5.9% of the cases, respectively, whereas they were always negative in the sarcomatous part of carcinosarcomas and blastoma. In the epithelial component of pleomorphic carcinomas, cytokeratin 7, TTF-1, and surfactant protein-A were positive in 76.4%, 58.8%, and 39.2% of the cases, respectively, whereas the same antibodies did not react with the epithelial component of carcinosarcomas; in the case of blastoma, the epithelial part of the tumor was positive for cytokeratin 7 and TTF-1, whereas it was negative for surfactant protein-A. Cytokeratin 20 was always negative. In our opinion, this study: 1) supports the metaplastic histogenetic theory for this group of tumors; 2) shows that cytokeratin 7 and TTF-1, but not surfactant protein-A, are useful immunohistochemical markers in this setting; 3) confirms that stage is at the moment the only significant prognostic parameter, as in conventional non-small cell lung carcinomas; and 4) shows that this group of tumors has a worse prognosis than conventional non-small cell lung carcinoma at surgically curable stages I, justifying their segregation as an independent histologic type in the WHO classification.

Molecular pathogenesis of pulmonary carcinosarcoma as determined by microdissection-based allelotyping

Pulmonary carcinosarcoma is a rare, biphasic tumor composed of malignant epithelial and mesenchymal elements. Its histogenesis is controversial in light of the presence of divergent cell lineages and the clonal nature of malignancy. To address these issues, we performed an extensive comparative genotypic analysis using microdissection to secure representative mesenchymal and epithelial components from each of six cases of pulmonary carcinosarcoma. Loss of heterozygosity was analyzed with a panel of 12 polymorphic microsatellite markers designed to indicate allelic loss and situated in proximity to known tumor suppressor genes located on 1p, 3p, 5q, 9p, 10q, and 17p. In accordance with the relatively greater biologic aggressiveness of this tumor type, both the epithelial and mesenchymal components showed extensive allelic loss, most notably for 3p, 5q, and 17p. More importantly, we found overall equivalent patterns of acquired allelic loss between the two components on an individual case basis, strongly supporting the monoclonal origin of these neoplasms. Minor differences in the allelic fingerprint between the two cell lineages could be explained by progressive accumulation of allelic loss alterations that appear to occur more frequently in the mesenchymal component of the tumor. The data support the efficacy of microdissection-based allelic fingerprinting to delineate the relationship between different morphologic components of a single neoplasm.

Spindle cell squamous carcinoma of the oesophagus: an analysis of 17 cases, with new immunohistochemical evidence for a clonal origin

AIMS

To study the morphological and immunohistochemical characteristics of spindle cell squamous carcinoma of the oesophagus, in order better to understand the histogenesis of this tumour.

METHODS AND RESULTS

In this study we analysed the morphological and immunohistochemical characteristics of 17 cases of spindle cell squamous carcinoma of the oesophagus. Most tumours were polypoid, but tumours with an ulcerated and infiltrative pattern were also observed. Histologically, most tumours were of superficial type, with a characteristic morphological aspect consisting of two types of tumour cells, i.e. differentiated squamous cells, and spindle cells with transition zones between the two components. On immunohistochemistry, the squamous cells were positive for cytokeratin and the spindle cells showed variable expression of cytokeratin, vimentin and smooth muscle actin. p53 protein was over-expressed in 10 cases, both tumour cell types showing strong nuclear positivity. In most tumours, E-cadherin was expressed in the squamous cells and absent in the spindle cells.

CONCLUSIONS

The similar pattern of p53 protein expression in the two tumour cell types of spindle cell squamous carcinoma of the oesophagus suggests their common origin. The change in adhesion molecule expression with loss of E-cadherin expression may be associated with the acquisition of spindle cell morphology by the squamous tumour cells.

Different subtypes of human lung adenocarcinoma caused by different etiological factors. Evidence from p53 mutational spectra

Human lung adenocarcinomas are only relatively weakly associated with tobacco smoke, and other etiological factors need to be clarified. These may also vary with the histopathology. Because the p53 mutation status (frequency and spectrum) of a carcinoma can provide clues to causative agents, we subclassified 113 adenocarcinomas into five cell types: hobnail, columnar/cuboidal, mixed, polygonal, and goblet (54, 23, 18, 13, and 5, respectively) and investigated relationships with p53 mutations and smoking history. In the hobnail cell type, a low mutational frequency (37%) and a high proportion of transitions (65%), especially G:C to A:T transitions at CpG dinucleotides (45%) associated with spontaneous mutations, were found with a weak relation to tobacco smoke. In contrast, a high mutation frequency (70%) with a higher proportion of transversions (50%), especially G:C to T:A (44%) on the nontranscribed DNA strand, caused by exogenous carcinogenic agents like tobacco smoke, were observed for the columnar cell type, as with squamous cell carcinomas. These results indicate that two major subtypes of lung adenocarcinoma exist, one probably caused by tobacco smoke, and the other possibly due to spontaneous mutations. For the prevention of lung adenocarcinomas, in addition to stopping tobacco smoking, the elucidation of endogenous mechanisms is important.

Leiomyosarcoma of the pulmonary vein

A case of a 74-year-old man with leiomyosarcoma of the pulmonary vein is reported. The patient felt transient chest oppression while playing golf 1 week before he visited a clinic with a common cold. He underwent an ultrasonographic examination of the heart, which showed a mass lesion in the left atrium. The preoperative clinical diagnosis was myxoma of the left atrium. Cardiac surgery revealed the mass to be a leiomyosarcoma, probably extending from the left inferior pulmonary vein. The patient underwent a left lower lobectomy of the lung, and the tumor was confirmed to have originated from the wall of the left inferior pulmonary vein. Although the patient had a metastatic lesion in the right axillary lymph node 11 months later, which was excised, he remained free of disease 14 months after the initial operation. Histologically, the tumors were composed of pleomorphic cells with bizarre nuclei and spindle cells with blunt-ended nuclei with 1-4 mitotic figures in 10 high power fields. Immunohistologically, the tumor cells were positive for alpha-smooth muscle actin and desmin. We reviewed 17 cases of leiomyosarcoma of the pulmonary vein (six males and 11 females with a mean age of 50 years in each group). The present case was the oldest in age and to our knowledge was the first reported case with metastasis in a distant lymph node.

Transition from squamous cell carcinoma to adenocarcinoma in adenosquamous carcinoma of the lung

The heterogeneity of tumor cells is frequently observed in lung cancer, but the clonality of these cells has not yet been established. The distinct components of 12 lung adenosquamous carcinomas were compared by genetic alterations of p53 and K-ras, chromosomal abnormalities at 9p21 and 9q31-32, and immunohistochemical reactions. The immunoreactivity of p53 was consistent in both adenocarcinomatous and squamous cell carcinomatous components as well as in the transitional areas, retaining the morphological characteristics of the distinct components. The same p53 mutation was found in both components of each tumor with p53 overexpression. No K-ras mutations were detected in any of the tumors examined. Three of the four tumors with chromosomal abnormalities detected, one at 9p21 and two at 9q31-32, had coincident abnormalities between the distinct components, whereas one tumor deleted homozygously at 9p21 (D9S259) in the adenocarcinomatous component with loss of heterozygosity in the other component. The expression of squamous cell carcinoma-related antigen in adenocarcinomatous components was significantly higher than that of lung adenocarcinomas (57 +/- 5.8% vs. 1.0 +/- 0.5%, P < 0.0001), whereas Mucin 1 expression is less in these components (9.0 +/- 4.9% vs. 55 +/- 8.2%, P = 0.003). These results suggest monoclonal transition from squamous cell carcinoma to adenocarcinoma in lung adenosquamous carcinoma.

Genetic profile of gliosarcomas

There are distinct genetic pathways leading to the glioblastoma, the most malignant astrocytic brain tumor. Primary (de novo) glioblastomas develop in older patients and are characterized by epidermal growth factor (EGF) receptor amplification/overexpression, p16 deletion, and PTEN mutations, whereas secondary glioblastomas that progressed from low-grade or anaplastic astrocytoma develop in younger patients and frequently contain p53 mutations. In this study, we assessed the genetic profile of gliosarcoma, a rare glioblastoma variant characterized by a biphasic tissue pattern with alternating areas displaying glial and mesenchymal differentiation. Single-strand conformation polymorphism followed by direct DNA sequencing revealed p53 mutations in five of 19 gliosarcomas (26%) and PTEN mutations in seven cases (37%). Homozygous p16 deletion was detected by differential polymerase chain reaction in seven (37%) gliosarcomas. The overall incidence of alterations in the Rb pathway (p16 deletion, CDK4 amplification, or loss of pRb immunoreactivity) was 53%, and these changes were mutually exclusive. Coamplification of CDK4 and MDM2 was detected in one gliosarcoma. None of the gliosarcomas showed amplification or overexpression of the EGF receptor. Thus gliosarcomas exhibit a genetic profile similar to that of primary (de novo) glioblastomas, except for the absence of EGFR amplification/overexpression. Identical PTEN mutations in the gliomatous and sarcomatous tumor components were found in two cases. Other biopsies contained p16 deletions, an identical p53 mutation, or coamplification of MDM2 and CDK4 in both tumor areas. This strongly supports the concept of a monoclonal origin of gliosarcomas and an evolution of the sarcomatous component due to aberrant mesenchymal differentiation in a highly malignant astrocytic neoplasm.

Carcinosarcomas of the lung: a clinicopathologic study of 66 patients

Carcinosarcoma is a malignant tumor having a mixture of carcinoma and sarcoma containing differentiated mesenchymal elements, such as malignant cartilage, bone, and skeletal muscle. These tumors have been linked histogenetically to pleomorphic carcinomas; it is unclear whether their clinical behavior is significantly different. To investigate this issue, we studied 66 cases of carcinosarcomas of the lung and compared them with cases from a previously published series of pleomorphic carcinomas. Carcinosarcomas show a male-to-female ratio of 7.25:1, with a mean and median age of 65 years. They most often present as solitary masses in the upper lobes and average 7 cm in diameter. Most (62%) were endobronchial or central tumors, whereas 38% were described as peripheral. The most frequent epithelial component was squamous cell carcinoma (46%), followed by adenocarcinoma (31%) and adenosquamous carcinoma (19%), whereas sarcomatous elements most frequently included rhabdomyosarcoma, chondrosarcoma, osteosarcoma, or combinations of these elements. Survival of patients with carcinosarcomas of lung was poor, with a 5-year survival rate of 21.3%. Of several clinical and pathologic parameters, only increased tumor size (with 6 cm as the optimal cutoff point) appeared to be related to reduced survival (p = 0.0195). In comparison with patients with pleomorphic carcinoma, patients with carcinosarcomas had no significant difference in the size of their tumors (p = 1.0), stage at presentation (p = 0.883), location in the lung (p = 0.073), or their overall survival (21.3% vs 15.0%) (p = 0.1038). A significantly greater proportion of patients with carcinosarcoma had squamous cell (p = 0.004) or adenosquamous (p = 0.016) carcinoma, whereas patients who had pleomorphic carcinoma showed a significantly greater frequency of adenocarcinoma (p = 0.029) and large cell carcinoma. The histologic differences between these two types of tumor suggest that they may be different entities with similar behavior, but additional studies are warranted to investigate this hypothesis.

Pulmonary carcinosarcoma: immunohistochemical and ultrastructural studies

A case of pulmonary carcinosarcoma in a 68-year-old male patient is reported. The tumor in the resected left upper lobe extended mainly endobronchially, invading the normal bronchial lumina and mucosa. The carcinomatous component consisted of poorly differentiated squamous cell carcinoma and was mainly located in the periphery of the tumor nests. The sarcomatous component consisted of chondrosarcoma and was mainly located in the center of the tumor nests. Tumor cells in the sarcomatous component reacted with anti-S-100 protein antibody and were surrounded with abundant homogeneous extracellular matrix staining positively with Alcian blue. The transition from the carcinomatous component to the sarcomatous component appeared to be very smooth. The tumor cells in both the carcinomatous and sarcomatous components reacted with anti-epithelial membrane antigen antibody. Ultrastructurally, the tumor cells with tonofibrils in the carcinomatous component were apposed and connected to each other by desmosomes. By contrast, in the sarcomatous component, the tumor cells had well-developed and dilated rough endoplasmic reticulum and were arranged loosely in a myxomatous matrix. Some tumor cells in the sarcomatous component had occasional tonofibrils, and were apposed and connected to each other by desmosome-like structures. It is shown for the first time, ultrastructurally and immunohistochemically, that the tumor cells in the sarcomatous component of pulmonary carcinosarcomas have features of both epithelial and mesenchymal cells. It is suggested that the sarcomatous component in the present case is derived from the carcinomatous component.

Bronchioloalveolar adenocarcinoma of lung: monoclonal origin for multifocal disease

In an attempt to understand the histogenesis and molecular pathogenesis of multifocal bronchioloalveolar lung carcinoma (BAC) we studied 28 cases of BAC using a topographic genotyping approach for the presence of K-ras exon 1 mutations and p53 loss of heterozygosity (LOH). This analytical approach demonstrated K-ras exon 1 mutations in 12.5% of solitary BACs, 40% of BACs with microscopic or macroscopic satellite lesions, and 60% of BACs with intrathoracic metastases. In all cases with K-ras mutations, the identical point mutation was present in the primary, satellite, and intrathoracic metastatic lesions. When p53 LOH was demonstrated in the primary lesion, it was also detected in the satellites and intrathoracic metastases. No significant association was noted between the presence of K-ras mutations and p53 LOH. The results strongly support a monoclonal origin of multifocal BACs. Furthermore, the findings support the theories explaining the origin of multifocal BAC by intraalveolar route of spread, intrapulmonary lymphatic spread, or aerosolization leading to implantation at different sites. A trend toward an increased frequency of K-ras mutations and p53 LOH in BACs with satellites or metastases compared to solitary BACs was noted.

Pathological-radiological correlations: pathological and radiological correlation of endobronchial neoplasms: part II, malignant tumors

The majority of lung neoplasms are malignant. Many of these are central and have an associated endobronchial component. Most such neoplasms are of surface epithelial origin; however, neoplasms of submucosal gland, mesenchymal, and lymphoreticular origin may also demonstrate an endobronchial component. Because of their endobronchial location and associated symptoms, these patients often present at an earlier stage than purely parenchymal lung malignancies. The radiographic features in such cases may be similar to those associated with benign endobronchial tumors; however, there are certain radiological signs that are more suggestive of a malignant process. Despite these circumstances, conservative management such as endoscopic excision are inappropriate in most instances. The clinicopathologic and radiological features of these lesions are detailed.