Sarcomatoid carcinoma of the lung. Immunohistochemical and ultrastructural studies of 14 cases

Metastatic sarcomatoid carcinoma to bone

BACKGROUND AND OBJECTIVES

Distinguishing sarcomatoid carcinoma from primary sarcoma is clinically important. We sought to characterize metastatic sarcomatoid bone disease and its management.

METHODS

We analyzed the characteristics of all cases of sarcomatoid carcinoma to bone at a single institution from 2001 to 2021, excluding patients with nonosseous metastases. Survival was evaluated using the Kaplan-Meier method.

RESULTS

We identified 15 cases of metastatic sarcomatoid carcinoma to bone. In seven cases the primary cancer was unknown at presentation. Renal cell carcinoma was suspected or confirmed in nine cases. Nine patients presented with pathologic fracture and two with concomitant visceral metastases. All patients underwent image-guided core needle or open biopsy. Ten required surgery for discrete osseous metastases; in four cases definitive surgery was delayed (median delay, 19 days) due to inability to rule out sarcoma with frozen section. No patients required reoperation or had construct failure. Thirteen died of disease; median survival was 17.5 months (interquartile range, 6.2-25.1).

CONCLUSIONS

Metastatic sarcomatoid carcinoma is a clinically challenging entity. Multidisciplinary input and communication are key to identifying the primary carcinoma, locating osseous metastases, and defining an operative fixation that will survive the remainder of the patient's life.

Primary Pulmonary Carcinomas with Spindle and/or Giant Cell Features: A Review with Emphasis in Classification and Pitfalls in Diagnosis

Primary carcinomas of the lung are vastly represented by the conventional types of adenocarcinomas or squamous cell carcinomas. However, there are other types of non-small cell carcinomas that although uncommon represent a meaningful group that often pose a problem not only in diagnosis but also in classification. Spindle cell and/or giant cell carcinomas, although uncommon represent an important group of primary lung carcinomas. Important to highlight is that current criteria are rather ambiguous and likely not up to date, which renders the classification of these tumors somewhat more obscure. In addition, with the daily use of immunohistochemical stains, the classification of these tumors may also pose a different problem in the proper allocation of these tumors. Proper classification is highly important in the selection process that takes place using such material for molecular analysis. The current molecular characteristics of these tumors are limited and lack more in-depth studies and analyses that can provide specific targets for the treatment of patients with these tumors. The current review attempts to highlight the shortcomings in the current classification and definitions of these neoplasms as well as the more current view regarding these tumors when the use of immunohistochemical stains is employed.

Chemotherapy for advanced pulmonary sarcomatoid carcinoma: a population-based propensity score matching study

OBJECTIVES

Pulmonary sarcomatoid carcinoma (PSC) is a rare histological type of non-small cell lung cancer (NSCLC). There are no specific treatment guidelines for PSC. For advanced PSC (stage II-IV), the role of chemotherapy is still controversial. The purpose of this study was to investigate the effect of chemotherapy on the prognosis of advanced PSC.

METHODS

A total of 960 patients with advanced PSC from the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2019 were enrolled in this study. To investigate the prognostic factors, the Cox proportional hazard regression model was conducted. A total of 642 cases were obtained after propensity score matching (PSM). The Kaplan‒Meier method was applied to compare overall survival (OS) and cancer-specific survival (CSS).

RESULTS

For all 960 cases included in this study, the Cox proportional hazard model was applied for prognostic analysis. Univariate and multivariate analyses showed that stage, T stage, N stage, M stage, surgery, and chemotherapy were prognostic factors for OS and CSS (P < 0.05). A total of 642 cases were obtained after PSM, with no significant difference between the two groups for all variables. Kaplan‒Meier curves indicated that for OS and CSS, the prognosis was significantly better in the chemotherapy group than in the no-chemotherapy group.

CONCLUSIONS

For advanced PSC, chemotherapy can significantly improve the OS and CSS of patients. Chemotherapy should be an important part of PSC treatment.

Primary spindle cell tumor originating from the liver that was difficult to diagnose

Background

It has been reported that hepatocellular carcinoma (HCC) with spindle cell tumor accounts for 1.8% of all HCCs, but spindle cell tumors that do not show an obvious conventional HCC are extremely rare. In this report, we describe a case of resection of a primary spindle cell tumor of the liver that was difficult to diagnose.

Case presentation

A 75-year-old man presented with fever and right chest pain. He was suspected of a giant primary diaphragmatic tumor of extrahepatic origin by imaging studies. The preoperative differential diagnosis included benign masses such as myxoid sarcoma and schwannoma, and we planned a diaphragmatic resection. Intraoperatively, however, dissection of the tumor from the liver was not possible, requiring an extended right posterior segmentectomy with combined resection of the diaphragm. The patient had a good postoperative course and 1 year has passed since the surgery with no recurrence. The pathology showed that the mass was located just below the hepatic capsule/parenchymal region and was adherent to the diaphragm, but there was no continuity. The morphology suggested a low-grade mesenchymal tumor such as a solitary fibrous tumor and perivascular epithelioid cell tumor, but immunostaining was negative, making the diagnosis difficult. Although some areas of high proliferative activity were observed, finally, the diagnosis of primary spindle cell tumor of the liver with smooth muscle differentiation was made based on the positive results of muscle markers such as αSMA, desmin, and h-caldesmon.

Conclusions

Spindle cell tumor arising from the liver is so rare that preoperative and pathological diagnosis is often difficult to reach. Although further studies are needed to elucidate and better understand this uncommon clinical entity, we consider that complete resection is necessary for the above case, which may contribute to long-term survival.

Sarcomatoid carcinoma of the lung

Sarcomatoid carcinoma (SC) of the lung is a rare histological subtype of nonsmall cell lung cancer and comprises a diagnostically and therapeutically challenging group of tumors. We report a patient of SC of the lung in an elderly patient who presented with a lung mass. Computed tomography-guided biopsy of the lung mass was done, which clinched the diagnosis. We present this case because of the rarity of this histological subtype and to expand understanding regarding this rare cancer.

Clinicopathological characteristics and prognostic factors of pulmonary sarcomatoid carcinoma: a large population analysis

Background

This study was conducted to identify the clinicopathological characteristics and survival outcomes of pulmonary sarcomatoid carcinoma (PSC), and to compare prognostic factors between elderly (≥65 years) and non-elderly (<65 years) patients.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients diagnosed with PSC between 2004 and 2016. The Kaplan-Meier method was used for overall survival (OS) and cancer-specific survival (CSS) analysis. The Cox proportional hazards model was used to detect independent prognostic factors. A propensity score matched (PSM) analysis was conducted to compare OS and CSS in elderly versus non-elderly PSC patients.

Results

A total of 1,039 eligible cases were identified, with a median follow-up of 6 months. The 5-year OS and CSS rates were 12.3% and 18.7%, respectively, and the median survival was 6 months. Multivariate analysis revealed that female (HR =0.750, P<0.004), surgery (HR =0.484, P<0.001), chemotherapy (HR =0.504, P<0.001), and radiation (HR =0.801, P=0.041) were independent favorable prognostic factors. There was a significant difference in the OS and CSS rates between elderly and non-elderly patients after PSM (P=0.007 and P=0.017, respectively). In multivariate analysis, the predictors for OS in the elderly patients were gender, tumor stage, and chemotherapy, whereas in the non-elderly patients, the predictors were tumor stage, chemotherapy, and surgery.

Conclusions

The PSC patients in our study had poor survival outcomes. Comprehensive treatment, including surgery, chemotherapy, and radiotherapy, could improve patient prognosis. Elderly patients had different clinicopathological characteristics, compared to non-elderly patients.

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 carcinoma: an analysis of a rare cancer from the Surveillance, Epidemiology, and End Results database

OBJECTIVES

Pulmonary sarcomatoid carcinoma (PSC) is a rare malignant neoplasm that accounts for a small percentage of non-small-cell lung carcinoma (NSCLC). At least 10% of PSCs has a spindle and/or giant cell component, which is often associated with a poor prognosis. We reviewed the Surveillance, Epidemiology, and End Results (SEER) database for the clinicopathological characteristics and surgical outcomes of PSCs.

METHODS

The SEER database (1973-2013) was queried for PSC. A comparison between PSC and other NSCLC patients was performed. Cox regression for overall survival (OS) and logistic regression for node-positive predictors were performed. A propensity-matched (1:2) analysis (including age, gender, grade and stage) among surgically treated cases was done to compare OS in PSC versus other NSCLCs.

RESULTS

A total of 955 899 NSCLC patients were identified; of these, 4987 patients had been diagnosed with PSC (0.52%). Men represented 60.9% of cases, with a median age of 68 years. The median size of the tumour was 5 cm and 3.5 cm in PSCs and NSCLCs, respectively (P < 0.001). PSC patients had significantly less Stage I, more high-grade tumours, advanced T stage, N+ disease and M1 disease (P < 0.001). In the PSC cohort, the most significant predictor of N+ disease on multivariate analysis was advanced T stage (P < 0.001). Predictors of OS in Stages I/II PSC on multivariate analysis were advanced age [P < 0.001, hazard ratio (HR) = 1.03], male gender (P = 0.024, HR = 1.25), carcinosarcoma (P = 0.002, HR = 1.76), grade (P = 0.033, HR = 1.81), T stage (P = 0.003, HR = 1.75), N status (P = 0.001, HR = 1.90) and surgical resection (P < 0.001, HR = 0.58). Among matched surgically resected cohorts, a poorer prognosis for OS was evident in PSCs in early stages (I/II) than in other NSCLCs (P = 0.009).

CONCLUSIONS

PSC patients present with more advanced stage and with worse survival outcomes than other NSCLC patients. While surgical resection conveys a survival advantage in PSC, this group represents a population at a high risk for relapse and should be evaluated for novel adjuvant therapies.

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.

The gastric carcinosarcoma with severe venous invasion: a case report

Background

Gastric carcinosarcoma with severe venous invasion is extremely rare, and to the best of our knowledge, this is the first reported case.

Case presentation

A 79-year-old man visited the Onomichi General Hospital following abnormal upper gastrointestinal series findings. Laboratory data demonstrated no anemia, and the serum carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels were not elevated. Endoscopy identified a Borrmann type III lesion in the cardiac end of the stomach. Abdominal contrast-enhanced computerized tomography (CT) indicated that the lesser curvature of the stomach wall was modestly enhanced with bulky lymph nodes. Pathological biopsy examination identified a group 5, papillary adenocarcinoma. We diagnosed advanced gastric cancer with bulky lymph nodes (cT4aN3M0, cStage IIIC). Following neoadjuvant chemotherapy, the patient underwent open total gastrectomy with D2 lymph node dissection. Histopathologically, the tumor consisted of two components: a tubular adenocarcinoma and a sarcoma. The tumor cells were mainly intravenous and were not detected in the gastric wall stroma; this resulted in a venous invasion. Immunohistochemical analysis revealed that the tumor was positive for vimentin and partly positive for desmin and cytokeratin CAM5.2. We diagnosed a true gastric carcinosarcoma with severe venous invasion. Abdominal CT 2 months after surgery showed a low density area in the liver, suggesting metastasis.

Conclusions

Carcinosarcomas with lymph node metastasis are sometimes reported, but progression into the vasculature is very rare. We present a case of carcinosarcoma with unusual progression characteristics.

Sarcomatoid Carcinoma: A Clinicopathological Profile of Two Cases with Diagnostic Emphasis

Sarcomatoid carcinoma (SC) is an unusual and aggressive variant of squamous cell carcinoma, which frequently recurs and metastasizes, and is associated with poor survival rate. For this reason, its accurate diagnosis is very important. It is considered to be a biphasic tumor made up of epithelial as well as spindle cell component, but of epithelial origin. The diagnosis often represents a clinicopathologic challenge, and immunohistochemistry plays a key role in the histopathological diagnosis. The reported cases in oral cavity are limited. Here, we present two cases of SC where the use of immunohistochemistry allowed us to achieve a conclusive diagnosis.

Treatment of Lung Carcinosarcoma and Other Rare Histologic Subtypes of Non-small Cell Lung Cancer

OPINION STATEMENT

Lung carcinosarcoma (PCS) and other histological subtypes of non-small cell lung cancer, such as primary pulmonary lymphoma (PPL), pulmonary carcinoid (PC), and primary pulmonary lymphoepithelioma-like carcinoma (LELC), are rare. For their low incidence, the diagnosis and treatment are still controversial. Some patients only need surgery, while others may need chemotherapy, radiotherapy, or targeted therapy. In this paper, we retrospectively reviewed the literature of some rare histological subtype of NSCLC for the recent 20 years, and try to get some conclusions.

Characteristics and Prognostic Analysis of 69 Patients With Pulmonary Sarcomatoid Carcinoma

BACKGROUND

Pulmonary sarcomatoid carcinoma (PSC) is a rare malignancy.

METHODS

A total of 69 patients with PSC treated at a single institution in southern China with long-term follow-up were evaluated in this study. We analyzed the clinical characteristics, immunohistochemical profiles, epidermal growth factor receptor mutation status, K-RAS mutation status, treatments, and prognosis.

RESULTS

PSC mainly occurred in young male patients with a history of smoking. Most patients received multimodality treatments and the majority had early-stage disease. The median survival time was 19.1 months, and the 5-year survival rate was 17.4%. The patients without distant metastasis, with normal or higher body mass index (≥18.5), with normal hemoglobin, with smaller tumor size (≤4 cm), and those who received complete resection had significantly better overall survival (P<0.05). The patients with pleomorphic carcinoma had much worse prognosis. In a Cox regression model, M stage, pathology, and having received a complete resection were independent prognostic factors (P<0.05).

CONCLUSIONS

PSC is a unique lung malignancy with poor prognosis. Patients receiving complete resection had better prognosis, likely a reflection of early-stage disease. Neither neoadjuvant nor adjuvant chemotherapy improved patient survival for those with early-stage disease. The retrospective design and small sample size limited the generalizability. Future multicenter collaborations may be necessary to determine the optimal treatment.

A Rare Case of Sarcomatoid Carcinoma of the Lung with Spine Metastasis, Including a Literature Review

BACKGROUND Sarcomatoid carcinoma is a rare, aggressive, malignant cancer composed of sarcoma and sarcoma-like components, and can occur in different organs such as the thyroid gland, bone, skin, breast, pancreas, liver, urinary tract, and lung. Pulmonary sarcomatoid carcinoma accounts for only a small percentage of lung cancers and has histological variants that include pleomorphic carcinoma, giant cell carcinoma, spindle cell carcinoma, carcinosarcoma, and pulmonary blastoma. CASE REPORT Here, we present a case of sarcomatoid carcinoma in a 63-year-old HIV-positive Hispanic male who presented with back pain, dry cough, and weight loss. A CT scan of his chest showed an ovoid mass in the lower lobe of the left lung, and an MRI of the spine showed a left lateral paraspinal soft tissue mass causing central canal stenosis and mild cord compression. The patient underwent laminectomy and resection of the spinal mass. A transthoracic needle biopsy of the lung and spinal masses had similar histopathology, and were indicative of sarcomatoid carcinoma. CONCLUSIONS We report a rare case of sarcomatoid carcinoma involving both the lung and spinal cord in the same patient. Sarcomatoid carcinomas of the lung have poor prognosis and are aggressive cancers. Moreover, our case also had the co-occurrence of HIV and sarcomatoid carcinoma.

Clinical Significance and Next-Generation Sequencing of Chinese Pulmonary Sarcomatoid Carcinoma

Pulmonary Sarcomatoid Carcinoma (PSC) constitutes a heterogeneous group of non-small-cell lung carcinomas (NSCLCs) with a poor prognosis. In this study, a group of 7 patients with PSC was studied. Microscope analysis of all 7 cases revealed a pleomorphic carcinoma subtype. Moreover, 5 cases (71.4%) were composed entirely of malignant sarcomatoid-like elements, and 2 cases (28.6%) were composed of malignant sarcomatoid-like elements and at least 10% adenocarcinoma-like elements. Immunohistochemically, the PSC components of all 7 cases were positive for vimentin and cytokeratins, including cytokeratin (CK) and cytokeratin 7 (CK7). Next-Generation Sequencing (NGS) was performed, and a total of 136 putative somatic variants and one gene fusion were identified, of which 16 variants were considered hot spot mutations, including the genes EGFR, EML4-ALK, MET, BRAF, PIK3CA, and TP53. Of these hot spot mutations, one sample expressing an EML4-ALK fusion was further confirmed by Ventana IHC, and one sample containing an EGFR exon 19 deletion was also confirmed. The NGS results imply that TP53 mutations occur often in PSCs and that EML4-ALK fusion events and EGFR exon deletions also occur in these rare tumors. Molecular targeted therapy may be a useful treatment strategy for these rare lung tumors.

"Sarcomatoid" carcinomas of the lung: a clinicopathological study of 86 cases with a new perspective on tumor classification

Pulmonary sarcomatoid carcinoma includes a heterogenous group of tumors difficult to diagnose and treat. We report the clinicopathological features of 86 such tumors, including 74 pleomorphic and 12 spindle cell carcinomas, and propose a novel approach to the classification of these neoplasms in an attempt to better guide patient management. The patients were 47 men and 39 women aged 36 to 87 years (mean, 63 years) who primarily presented with shortness of breath, cough, and chest pain. Eighty-six percent of patients had a smoking history. Histologically, the pleomorphic carcinomas consisted of spindle and/or giant cells with varying proportions of conventional non-small cell carcinoma in the form of adenocarcinoma (n=29), squamous cell carcinoma (n=10), or large cell carcinoma (n=18); 17 cases contained a mix of spindle and giant cells only. The 12 spindle cell carcinomas consisted of spindle cells only. Based on the combined histopathologic and immunohistochemical features of these tumors, we were able to reanalyze the spectrum of these lesions and reclassify them accordingly. Statistical analysis revealed an overall survival at 3, 5, and 10 years of 42.9%, 34.6%, and 23.5%, respectively, and a median survival of 15 months. Log-rank test showed that in multivariate analysis, only pathological T stage was a factor associated with prognosis. The current classification of pulmonary sarcomatoid carcinomas precludes optimal triaging of these tumors with the risk of denying patients access to novel treatment. Our proposal for a reclassification of these tumors would more accurately guide patient management and facilitate targeted therapies.

The pivotal role of pathology in the management of lung cancer

The last decade has seen significant advances in our understanding of lung cancer biology and management. Identification of key driver events in lung carcinogenesis has contributed to the development of targeted lung cancer therapies, heralding the era of personalised medicine for lung cancer. As a result, histological subtyping and molecular testing has become of paramount importance, placing increasing demands on often small diagnostic specimens. This has triggered the review and development of the first structured classification of lung cancer in small biopsy/cytology specimens and a new classification of lung adenocarcinoma from the IASLC/ATS/ERS. These have enhanced the clinical relevance of pathological diagnosis, and emphasise the role of the modern surgical pathologist as an integral member of the multidisciplinary team, playing a crucial role in clinical trials and determining appropriate and timely management for patients with lung cancer.

Rapidly growing esophageal carcinosarcoma reduced by neoadjuvant radiotherapy alone

Esophageal carcinosarcoma is a rare malignant neoplasm consisting of both carcinomatous and sarcomatous components. It is generally treated by surgery, radiotherapy and chemotherapy according to the protocols used for other esophageal cancers. However, the treatment of esophageal carcinosarcoma by radiotherapy alone before surgery has not been previously described. We report a patient with a rapidly growing esophageal carcinosarcoma that was efficiently reduced by neoadjuvant radiotherapy alone. A previously healthy 69-year-old man was admitted with dysphagia. Initial esophagogastroduodenoscopy (EGD) revealed a small nodular polypoid lesion of about 10 mm in the middle esophagus. A second EGD 1 month later showed that the tumor had expanded into a huge mass. A biopsy specimen revealed that the tumor comprised squamous cell carcinoma with spindle cell components, and the tumor was diagnosed as carcinosarcoma which was diagnosed as stage I (T1bN0M0). Due to renal dysfunction, the patient was treated with neoadjuvant radiotherapy (40 Gy) without chemotherapy. A third EGD 1 month later revealed remarkable tumor reduction. He then underwent total esophagectomy with regional lymph node dissection (pStage 0, pT1aN0M0). After surgical operation, the patient was followed up without adjuvant therapy. Whole body computed tomography revealed lung metastasis 14 months after surgery, and the patient died 2 months later. The neoadjuvant radiotherapy for esophageal carcinosarcoma was considered to have contributed to the subsequent surgery and his prolonged survival time. Thus, radiotherapy alone might be a suitable neoadjuvant therapy for esophageal carcinosarcomas.

Immunohistochemical study of 36 cases of pulmonary sarcomatoid carcinoma--sensitivity of TTF-1 is superior to napsin

Immunohistochemistry is often used to distinguish pulmonary sarcomatoid carcinoma from morphologic mimics. Napsin-A is a pulmonary adenocarcinoma marker, but literature on expression in sarcomatoid carcinoma is limited. Thirty-six cases of sarcomatoid carcinoma were stained for napsin, TTF-1, Oscar, CAM5.2, AE1/AE3, desmin, SMA, S-100, CK5/6, calretinin, D2-40, and WT1. Patients were 24 men and 12 women (mean, 70 years; range, 46-93). There were 27 pleomorphic carcinomas, 5 spindle cell carcinomas, 3 carcinosarcomas, and 1 giant cell carcinoma. Cases were positive for at least 1 keratin: AE1/3 was positive in all 36 cases; Oscar, in 34 cases (94%); and CAM5.2, in 32 cases (89%, weaker/more focal). Napsin was positive in 14 cases (39%): 8 diffuse, 3 focal, and 3 rare cells. TTF-1 was positive in 22 cases (61%): 15 diffuse, 3 focal, and 4 rare cells. No cases were napsin positive and negative for TTF-1. Variable staining for mesothelial markers was observed, including positivity for calretinin (12 cases, 33%), WT1 (6 cases, 17%), D2-40 (5 cases, 14%), and CK5/6 (9 cases, 25%). Mesenchymal markers were also sometimes positive (usually focal), including S-100 (4 cases, 11%), desmin (4 cases, 11%), and SMA (7 cases, 19%, 1 diffuse). In conclusion, TTF-1 is more sensitive than napsin for detection of sarcomatoid carcinoma, and no cases were positive for napsin but negative for TTF-1. CAM5.2 is less sensitive than AE1/AE3 and Oscar. Use of a thoughtful immunohistochemical panel is important in the evaluation of sarcomatoid carcinoma because mesothelial and mesenchymal markers can be expressed.

Fine-needle aspiration cytology of pleomorphic carcinomas of the lung

Background

Pleomorphic carcinoma (PC) is a rare pulmonary malignancy. Because of its rarity and histological heterogeneity, cytopathologists might suspect PC only rarely on the basis of its cytological specimen. In addition, cytological findings from fine needle aspiration (FNA) specimens have rarely been described. Hence, we investigated the cytological features of FNA in the cases of PC.

Methods

We reviewed 7 FNA specimens of PC. The patients had undergone surgical resection at the Korea Cancer Center Hospital between 2007 and 2011. The cytological features of PC were assessed and compared with the histopathological features of the corresponding surgical specimen. Immunocytochemical analysis with cytokeratin and vimentin was performed on the cell blocks.

Results

The tumor cells were either dispersed or arranged in loose aggregates, and generally lacked any glandular or squamous differentiation. Pleomorphic or spindle shape tumor cells were observed, and mono-, bi-, or multi-nucleated giant cells were frequently observed. The background showed necrosis and contained numerous lymphocytes and neutrophils. Immunocytochemically, the tumor cells were positive for cytokeratin and vimentin.

Conclusions

PC displays characteristic cytological features. It might therefore be possible to make an accurate diagnosis of PC by assessing the degree of nuclear atypia.

Multiple carcinosarcomas of the esophagus and stomach

Carcinosarcoma is an uncommon biphasic malignant neoplasm consisting of both carcinomatous and sarcomatous components. We report a case of an 84-year-old male with multiple carcinosarcomas occurring in the esophagus and stomach. Endoscopically, a bulky pedunculated polypoid lesion was observed in the middle of the esophagus and a huge discoid lesion in the lesser curvature. The patient received esophageal endoscopic mucosal resection, and the specimen measured 4×2.5×1.5 cm. Microscopically, the esophageal tumor consisted of several polymorphic spindle cells mixed with squamous cells, while the gastric biopsies revealed carcinomatous cells with evident abnormal karyokinesis and polymorphous spindle cells. Immunohistochemically, the resected tumor stained positively for the epithelial markers, epithelial membrane antigen (EMA) and cytokeratin 19 (CK 19), and the mesenchymal markers, smooth muscle actin (SMA) and vimentin. The gastric lesion stained positively for CK AE1/AE3, actin and vimentin, but was negative for EMA. Both lesions were positive for neuron specific enolase (NSE), demonstrating neuroendocrine differentiation. The patient succumbed seven months after being discharged from hospital. To our knowledge, this is the first case in the literature that describes multiple carcinosarcomas arising from the esophagus and stomach. A review of the available literature is also presented.

The changing pathology of lung cancer

Lung cancer classification is of paramount importance in determining the treatment for oncologic patients. Most lung cancers are non-small cell lung carcinomas (NSCLC), which are further subclassified into squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Lung neuroendocrine tumors are subclassified into typical carcinoid, atypical carcinoid, small cell carcinoma, and large cell neuroendocrine carcinoma. In NSCLC in particular, the histologic classification and tumor mutation analysis are central to today's targeted therapy and personalized treatment. This article discusses the current diagnostic criteria for classification of NSCLC and lung neuroendocrine tumors and implications for oncologic treatment.

Immunohistochemical overexpression of platelet-derived growth factor receptor-beta (PDGFR-β) is associated with PDGFRB gene copy number gain in sarcomatoid non-small-cell lung cancer

Sarcomatoid non-small cell lung cancer (NSCLC) is an uncommon histologic variant that has not been molecularly well-characterized. We conducted immunohistochemical and fluorescence in situ hybridization studies of PDGF-B/PDGFR-b on archived surgically resected specimens and showed high PDGFR-b IHC expression and gene copy number gain. Further studies are warranted to determine whether PDGFR-b is a feasible therapeutic target in this population.

INTRODUCTION

Sarcomatoid non-small cell lung cancer (NSCLC) is an uncommon histologic variant that has not been molecularly well-characterized. We hypothesized that the PDGF-B/PDGF-Rβ pathway may be dysregulated in sarcomatoid lung cancer.

METHODS

We conducted immunohistochemical (IHC) and gene copy number gain studies of PDGF-B/PDGFR-β on archived surgically resected specimens, 43 sarcomatoid NSCLCs and 42 control NSCLCs that were age, gender and stage-matched. Biomarkers were correlated to patient demographics, tumor characteristics, and survival.

RESULTS

Sarcomatoid tumors had higher PDGFR-β IHC expression than control NSCLC (median score 2.69 vs. 1.93; P < 0.0001). No difference was seen between the two groups of PDGF-B IHC expression; and neither PDGF-B nor PDGFR-β IHC levels correlated with gender, age, clinical or pathologic TNM status, or overall survival. PDGFRB gene copy number was evaluated by FISH using three ways: presence of amplification, gene copy number gain, and gene copy ratio between tumor and normal tissue. PDGFRB gene copy number gain was associated with sarcomatoid histology (P = 0.006), lower clinical and pathologic T-stage (P = 0.07, P = 0.048), and higher pathologic N-stage (P = 0.013). Sarcomatoid NSCLC patients (P = 0.006) and female patients (P = 0.03) had higher gene copy ratios above 1.83. Higher PDGFR-β IHC expression in tumor cells was associated with gene copy number gain (P = 0.021) and higher gene copy ratio status (P = 0.005).

CONCLUSION

This is the first study to demonstrate high PDGFR-β IHC expression and gene copy number gain in sarcomatoid NSCLC tumors and suggests that further studies are warranted to determine whether PDGFR-β is a feasible therapeutic target in this population.

The Classification of Lung Carcinoma: Time to Change the Morphology-Based Approach?

Morphology still remains the cornerstone in lung cancer classification and always has been accompanying pathologists in their daily activity, even though several ancillary techniques have been incorporated over time to improve diagnostic, prognostic, and predictive capabilities in lung cancer. Currently, we are also faced with a global rethinking of lung cancer care, especially once novel therapy strategies have been made available on the basis of the diverse characteristics of tumors. Although morphology still remains a not easily replaceable tool for lung cancer classification, we are now challenged by the need of offering clinicians more detailed subtyping of non-small-cell lung cancer especially in event of limited diagnostic material, poorly differentiated tumors, or unresectable lesions. Close integration of improved morphology, immunohistochemistry, and molecular tests will be able to not only sharpen our diagnostic algorithms and prognostic and predictive potentialities but also get insights into several lung cancer biology issues, such as histogenesis and new classification schemes.

Sarcomatoid carcinoma of the lung: histologic criteria and common lesions in the differential diagnosis

CONTEXT

Sarcomatoid carcinoma of the lung is a subset of poorly differentiated non-small cell lung cancers that are diagnostically challenging because they are uncommon, may reveal little of their parent cell of origin, and overlap morphologically with other anaplastic epithelioid and spindle cell tumors that can be primary in, or metastatic to, the lung and pleura.

OBJECTIVE

To review the current histologic classification and diagnostic criteria that identify the 5 subtypes of sarcomatoid carcinoma of the lung and to discuss the most common tumors in the differential diagnosis.

DESIGN

Published classification systems from the World Health Organization and pertinent peer-reviewed articles indexed in PubMed (National Library of Medicine) form the basis of this review.

CONCLUSIONS

Identification of sarcomatoid carcinoma of the lung requires knowledge of specific histologic criteria that define the 5 subgroups, targeted immunohistochemical studies, and correlation with chest imaging to assess distribution of disease and to avoid misdiagnosis.

Sarcomatoid lung carcinomas: a case series

We report on three Caucasian Greeks 2 males and 1 female (67, 54 and 62 years old) that were operated with sarcomatoid carcinoma of the lung, an uncommon tumor that sometimes is referred as pleomorphic carcinoma (spindle and giant cell carcinomas). These tumors are encountered in the thorax far more often than true sarcomas. There are many erroneous reports of pulmonary sarcomas made before the advent of adjunctive pathologic screening, including immunohistochemical studies. Pulmonary Sarcomatoid Carcinomas represent 0.2-1% of all lung cancers in different series and they are considered that they are not significantly aggressive than ordinary lung carcinoma.

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.

Pulmonary Sarcomatous Tumors

Context.—Sarcomatous pulmonary neoplasms are a rare and diagnostically challenging group of tumors. Primary pulmonary sarcomas must be distinguished from the more frequent occurrence of sarcoma metastatic to the lung, primary pulmonary sarcomatoid carcinoma, and diffuse malignant mesothelioma involving the lung. In current practice, the general availability of ancillary diagnostic techniques, such as immunohistochemistry and molecular analysis, can reliably classify many sarcomatoid lesions.

Objective.—To review the literature and report on additional primary material about the application of immunohistochemistry and molecular analysis in the differential diagnosis pulmonary sarcomatous neoplasms.

Data Sources.—Literature review of relevant articles indexed in PubMed (National Library of Medicine) between 1961 and 2007 and primary material from the author's institution.

Conclusions.—This review discusses specific criteria for the diagnosis of primary lung sarcomas and offers a practical approach to excluding other sarcoma-like lesions involving the lung. The pathologist has an essential role in evaluating these tumors and will often be the first to suggest an unusual, alternative diagnosis, which may have significant implications for patient care, therapy, and prognosis.

Palliative chemotherapy for pulmonary pleomorphic carcinoma

Pulmonary pleomorphic carcinoma is a rare tumor of the lung, which is believed to spread at an early stage and to have an aggressive clinical course. The efficacy of chemotherapy for advanced pulmonary pleomorphic carcinoma has not been defined. The objective of this study was to evaluate the efficacy of palliative chemotherapy for pulmonary pleomorphic carcinoma. Thirteen consecutive patients who received palliative chemotherapy for advanced pulmonary pleomorphic carcinoma were investigated. All 13 patients were treated using chemotherapy regimens known to be active for the treatment of advanced non-small cell lung cancer (NSCLC). Eleven patients (85%) had progressive disease and two (15%) had stable disease after first-line chemotherapy. No patient achieved an objective response (objective response rate, 0%; 95% confidence interval, 0-23%). Of the 13, eight were given second-line chemotherapy, and all had progressive disease after second-line chemotherapy (objective response rate, 0%; 95% CI, 0-32%). Median overall survival from the initiation of first-line palliative chemotherapy was only 5 months (range, 2-12) with a median follow-up of 16 months. Advanced pulmonary pleomorphic carcinoma showed poor response to chemotherapy regimens that provide active treatment for NSCLC. Novel treatment approaches are required for pulmonary pleomorphic carcinoma.

Sarcomatoid carcinoma of the lung: a predictor of poor prognosis

BACKGROUND

Sarcomatoid cancer (SARC) of the lung is a rare histologic type of non-small cell lung cancer (NSCLC). Although believed to be associated with poor prognosis, its effect on survival and recurrence has not been well defined. Our goal was to determine the prognostic significance of SARC histology in patients undergoing pulmonary resection.

METHODS

We retrospectively evaluated all patients who underwent pulmonary resection for NSCLC during a 20-year period at the University of Texas MD Anderson Cancer Center and compared recurrence and survival rates of patients with SARC with a cohort of patients with typical NSCLC. To account for known prognostic factors such as smoking status, age, gender, pathologic stage, and adjuvant therapy, we used one-to-one matching based on propensity scores.

RESULTS

The study included 63 SARC patients and 1133 NSCLC patients with complete data. Propensity score matching identified 63 NSCLC patients that were similar to the 63 SARC patients from known clinical factors. The 5-year survival for SARC patients was 24.5% compared with 46.3% for NSCLC patients (p = 0.01); median time to recurrence was 11.3 months and 61.4 months, respectively (p = 0.001).

CONCLUSIONS

Compared with other histologic subtypes, SARC behaves in an aggressive fashion. These tumors are frequently symptomatic, are locally advanced, and have higher rates of recurrence. Future investigation of novel treatment approaches is warranted. Nonsurgical treatment modalities may be appropriate for patients with clinically advanced disease.

Sarcomatoid lung cancer (spindle/giant cells): An aggressive disease?

OBJECTIVE

We investigated the clinical, surgical, and pathologic features of sarcomatoid lung carcinomas with spindle/giant cells, giving special attention to the prognostic behavior of these rare tumors.

METHODS

Surgical specimens from 39 patients (29 men and 10 women; mean age, 61 years) were examined by means of light microscopy. Preoperative and postoperative data were collected, and survival was calculated by using the Kaplan-Meier method.

RESULTS

Nineteen patients were diagnosed with cancer preoperatively. Only one sarcomatoid tumor had been diagnosed. Presenting symptoms were noted in 85% of patients, and complete resection was achieved in 37 tumors. Postoperative pTNM staging: T2/T3/T4, 22/15/2; N0/N1/N2, 28/8/3; 15 stage IB, 14 stage IIB, 7 stage IIIA, 2 stage IIIB, and 1 stage IV. Histopathologic analysis revealed necrosis in 90% of the tumors (34 pleomorphic, 3 spindle cell, and 2 giant cell carcinomas). During follow-up (median, 24 months), 21 patients died of disease recurrence, and 3 died of postoperative complications. The 5-year survival rate (33%; median, 11 months) was negatively influenced by large tumors (7.5% survival for > or =7 cm vs 56% for <7 cm, P = .0026). The disease-free interval was significant for patients who relapsed (0% for disease-free interval <6 months vs 33% for disease-free interval > or =6 months, P = .0019).

CONCLUSIONS

A highly heterogeneous group, spindle/giant cell lung carcinomas tend to be symptomatic, peripheral, and necrotic. Preoperative diagnosis is difficult. Most patients in our study relapsed and died the first year after surgical intervention. Surgical intervention can permit long-term survival, but adjuvant therapy warrants consideration because of the aggressive nature of these tumors.

Cutaneous carcinosarcoma: adnexal vs. epidermal types define high- and low-risk tumors. Results of a meta-analysis

OBJECTIVE

We report four cases of cutaneous carcinosarcoma (CS) and perform a meta-analysis of the cutaneous CS literature.

RESULTS

CS occurred in elderly patients (mean of 80 years) on sun-damaged skin, and were keratotic papules of short duration. They did not recur after excision. CS exhibited basal cell carcinoma mixed with atypical fibroxanthoma cell populations. Immunophenotyping revealed vimentin+/keratin- spindle cells and vimentin-/keratin+ epithelial cells. Three cases exhibited p53 protein expression of both carcinomatous and sarcomatous components. Literature review identified 38 cases of cutaneous CS that could be broadly classified into two distinct groups. Epidermal-derived (basal or squamous cell carcinoma epithelial component) CS arose on the sun-damaged skin of the head and neck of elderly males (mean age 72 years) and had a 70% 5-year disease-free survival. In contrast, adnexal CS (spiradenocarcinoma, porocarcinoma, proliferating tricholemmal cystic carcinoma, or matrical carcinoma) occurred in younger patients (mean age 58 years), showed recent growth in a long-standing nodule and had a 25% 5-year disease-free survival. Age less than 65 years, recent growth, long-standing skin tumor, and tumor size greater than 2 cm significantly correlated with poor outcome.

CONCLUSIONS

Cutaneous CS is an aggressive skin cancer with high risk for advanced disease. Significant risk factors exist whose identification will allow for better management of CS patients.

Localized pleural malignant mesothelioma

The occurrence of pleural malignant mesothelioma (MM) is unusual and the cases that appear as a localized tumor are extremely rare. A case of localized pleural MM including immunohistochemical findings is presented. A 70-year-old man had an abnormal shadow found during a routine roentgenogram at an annual health checkup and was admitted to Toneyama National Hospital (Toyonaka, Osaka, Japan) for detailed examinations. Chest X-rays showed a 2 x 5 cm-sized nodule with relatively smooth margins in the right segment three. Computed tomography (CT) showed an extrapleural mass with a smooth surface and a thickened parietal pleura, and results of a biopsy performed under CT scanning yielded MM. Systematic examinations did not show any metastasis and the patient underwent surgery for removal of the mass. The resected tumor, measuring 3.2 x 3.1 cm, was firm, partially encapsulated, and irregularly shaped. Pathological examinations revealed that it consisted of large polygonal cells, partially showing myxoid patterns, which led to a diagnosis of localized pleural MM. Tumor recurrence was seen, and the duration between initial symptoms and death was 29 months. This case suggests that localized pleural MM has a high proliferative potential and aggressive course, and is considered an early stage of diffuse pleural MM.

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.

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.

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.

Transdifferentiation of neoplastic cells

Transdifferentiation is a process in which a stable cell's phenotype changes to that of a distinctly different cell type. It occurs during certain physiological processes and leads to transition of tumor cell phenotypes. The latter process includes neoplastic epithelial-epithelial transition, neoplastic epithelial-mesenchymal transition, neoplastic mesenchymal-epithelial transition and transition between non-neural and neural neoplastic cell. This phonomenon is exemplified in some origin-debated tumors, such as carcinosarcoma, pleomorphic adenoma, synovial sarcoma, Ewing's/pPNET, and malignant fibrohistiocytoma. We propose that differentiation disturbance of cancer cells should include not only undifferentiation and dedifferentiation, but also transdifferentiation as well. Tumor cell transdifferentiation may be influenced or determined by cellular genetic instabilities, proliferation and apoptosis, as well as by extracellular matrix and growth factors.

Pancreatic mucinous cystic neoplasms with sarcomatous stroma: molecular evidence for monoclonal origin with subsequent divergence of the epithelial and sarcomatous components

Neoplasms with mixed carcinomatous and sarcomatous growth patterns occur in many organs and tissues. The pathogenesis of these cancers is thought to be either the result of two independent neoplastic processes merging to form a single tumor, or a neoplasm of monoclonal origin that develops phenotypic diversity. To address this issue, we characterized molecular alterations in separately microdissected epithelial and sarcomatous areas in three cases of pancreatic mucinous cystic neoplasms with sarcomatous stroma. Using microsatellite markers for six chromosomal loci commonly deleted in infiltrating ductal adenocarcinomas of the pancreas, we found genetic alterations to be virtually identical between the sarcomatous and epithelial components of two of the three neoplasms. In the third neoplasm, we found allelic losses and retentions to be identical at five of the six chromosomal loci, but at a single locus, we noted allelic loss in the neoplastic epithelial component but not the sarcomatous component. The same neoplasms were also analyzed for activating point mutations in codon 12 of the K-ras gene by using mutant-enriched polymerase chain reaction and allele-specific oligonucleotide hybridization. A K-ras mutation was identified in the epithelial component of one of the three neoplasms (the same tumor with an additional allelic loss in the neoplastic epithelial cells), but the sarcomatous component of this tumor was wild-type at codon 12 of K-ras, as were both components of the other two neoplasms. Overall, these results suggest a monoclonal origin with subsequent divergence of the neoplastic epithelial and sarcomatous portions of these neoplasms.

Spindle cell thymic carcinoma: clinicopathologic and immunohistochemical study of a distinctive variant of primary thymic epithelial neoplasm

We report 16 cases of a distinctive variant of primary thymic epithelial neoplasm characterized by prominent spindling of the tumor cells. The patients were seven women and nine men aged 23 to 82 years (mean, 54 years). The lesions presented as anterior mediastinal masses without clinical or radiographic evidence of tumor elsewhere. Most patients had chest pain, dyspnea, and cough; in five patients, the tumors were asymptomatic and were discovered on routine clinical examination. Grossly, the lesions were firm, well-circumscribed, and locally infiltrative, and had a firm cut surface with foci of hemorrhage, necrosis, and cystic changes. Most of the tumors were treated by complete surgical excision. Histologically, they were characterized by a spindle cell proliferation showing varying degrees of atypia and mitotic activity. In 12 cases, transitions could be seen with areas that showed the features of conventional spindle cell thymoma. In two cases, areas showing features of poorly differentiated (lymphoepitheliomalike) carcinoma and anaplastic carcinoma could also be observed. Immunohistochemical studies in 10 cases showed strong positivity of the spindle tumor cells for CAM5.2 cytokeratin, and negative staining for a panel of antibodies including epithelial membrane antigen, carcinoembryonic antigen, actin, desmin, vimentin, S-100 protein, HMB45, CD34, CD5, and CD99. Clinical follow-up of eight patients showed an aggressive biologic behavior with recurrence, metastasis, and death by tumor in five of them 2 to 5 years after diagnosis. Based on these findings, the present tumors are interpreted as an unusual spindle cell variant of thymic carcinoma. The close association of these cases with areas showing the features of spindle cell thymoma within the same tumor mass suggests that some of these lesions may arise as a result of malignant transformation in a preexisting spindle cell thymoma.

A case of synchronous double primary lung cancer with neuroendocrine features

We report a case of unique double primary lung cancers with neuroendocrine features in a 63-year-old male smoker. The mass in the left lower lobe (LLL) was a small cell/large cell carcinoma with spindle cell sarcomatous areas and organoid structure. The mass in the left upper lobe (LUL) was a tubular adenocarcinoma with neuroendocrine features including organoid nests showing occasional rosette formation, nuclear palisading in the periphery of the nests and positive immunoreaction for CD56, chromogranin A and synaptophysin. The difference in histological structures between the two masses led us to diagnose double primary lung cancer. The combination of small cell lung carcinoma and spindle cell carcinoma is very uncommon. The relationship between LLL and LUL tumors remains unclear. Multiple lung cancers with neuroendocrine features have only rarely been reported in the literature. The patient in our case died of widespread cancer 2 years and 4 months after the surgery without adjuvant chemotherapy, a longer postoperative survival time than in cases of ordinary extensive small cell lung cancer. Multiple lung cancers with neuroendocrine features are extremely rare and similar cases have not been reported in the literature. Neuroendocrine differentiation has attracted widespread attention and, therefore, examining neuroendocrine features in lung cancers is important.

Primary lung tumors infiltrated by osteoclast-like giant cells

Six primary lung tumors with numerous multinucleated osteoclast-like giant cells (OLGCs) and no osteogenic component were evaluated histologically and immunohistochemically to examine pulmonary lesions inciting an OLGC response. The patients comprised four women and two men ranging in age from 61 to 80 years (average age, 69 years). The tumors consisted of one adenocarcinoma, two sarcomatoid carcinomas, and three giant cell variants of malignant fibrous histiocytoma. One tumor was endobronchial in location, while five were situated peripherally. Tumor diameter spanned from 1 to 6.5 cm (average, 2.7 cm). In addition to the giant cells, common characteristics included the malignant nature of the neoplasms and, in five of six cases, histologically malignant mesenchyme. This array of cases exemplifies the variability of lung lesions which may elicit an OLGC inflammatory response resulting in areas resembling the giant cell variant of malignant fibrous histiocytoma. The results of this study suggest that OLGCs occur preferentially in malignant rather than benign nonosteogenic lung tumors and that sarcomatoid regions of malignant tumors are more likely to be infiltrated by OLGCs than epithelial regions.