Pulmonary carcinomas with a sarcomatoid element: an immunocytochemical and ultrastructural analysis

Biologics and Non-Biologics Immunosuppressive Treatments for IgA Nephropathy in Both Adults and Children

Immunoglobulin A nephropathy represents the most prevalent cause of glomerulonephritis worldwide and may lead to renal failure in a relevant number of cases in both paediatric and adult subjects. Although their pathogenesis is still largely unclear, evidence of immune abnormalities provides the background for the use of immunosuppressive drugs, such as corticosteroids, calcineurin inhibitors, and antiproliferative and alkylating agents. Unfortunately, these treatments fail to achieve a sustained remission in a significant percentage of affected patients and are burdened by significant toxicities. Recent developments of new biologics, including anti-BAFF/APRIL inhibitors and molecules targeting complement components, offered the opportunity to selectively target immune cell subsets or activation pathways, leading to more effective and safer hypothesis-driven treatments. However, studies testing new biologic agents in IgAN should also consider paediatric populations to address the unique needs of children and close the therapeutic gap between adult and paediatric care.

Duodenal Carcinosarcoma: An Apple-Core Lesion Causing Gastric Outlet Obstruction

We present a case of a 58-year-old male with a rare duodenal carcinosarcoma causing gastric outlet obstruction. Despite its aggressive nature and poor prognosis, with only 12 documented cases in the literature, this report sheds light on the clinical presentation and challenges in diagnosis and treatment. Carcinosarcoma, characterized by both carcinomatous and sarcomatous elements, poses difficulties in management due to its diverse tissue characteristics. Surgical resection remains the primary treatment, although the prognosis remains grim, emphasizing the need for further research into advanced therapeutic strategies to improve patient outcomes. This case underscores the rarity and clinical complexities associated with duodenal carcinosarcomas.

A case of rapidly progressing sarcomatous intrahepatic cholangiocarcinoma with suddenly appearing lymph node metastasis

BACKGROUND

The sarcomatous variant of carcinoma is relatively rare in intrahepatic cholangiocarcinoma (ICC). Sarcomatous ICC (SICC) is associated with a poorer prognosis compared with ICC. SICC is rarely diagnosed before surgery due to non-descriptive findings; it progresses rapidly, resulting in miserable prognosis. Here, we report a case of rapidly progressing SICC that showed a clinically significant tumor growth rate.

CASE PRESENTATION

A 77-year-old woman who had undergone ileocecal resection for cecal cancer 5 years previously was found to have elevated levels of the tumor marker carbohydrate antigen 19-9. Although an abdominal computed tomography (CT) scan did not detect any liver mass lesions until 3 months before this serum examination, the subsequent CT scan revealed a hypodensity 20 mm mass lesion in the right anterior section. Contrast-enhanced CT and magnetic resonance imaging revealed peripheral enhancement in the arterial-to-equilibrium phase. Fluorodeoxyglucose positron emission tomography revealed uptake in the lesion. None of the imaging modalities showed lymph node swelling or distant metastases. She underwent hepatectomy under the diagnosis of ICC or an atypical metastasis from previous cecal cancer. Although preoperative images showed no suspicious lymph node metastasis 3 weeks prior, the hilar lymph node swelled 3 cm and contained adenocarcinoma. Consequently, the patient underwent right anterior sectionectomy and lymph node dissection of the hepatoduodenal ligament. Histopathological examination revealed that the liver tumor was a poorly differentiated adenocarcinoma with sarcomatous pattern. While the patient received adjuvant gemcitabine and S-1 therapy, lymph node metastasis appeared in the mediastinum 13 months after the surgery. She received gemcitabine + cisplatin + S-1 therapy but died 20 months after surgery.

CONCLUSION

SICC and lymph node metastasis clinically appeared within 3 months and 3 weeks, respectively. Suspected ICC that rapidly progresses should be considered SICC and treated with early resection. SICC is often missed in clinical diagnosis and has a poor prognosis, even after curative resection. While an alternative strategy involving preoperative biopsy and neoadjuvant therapy may be beneficial, it should be approached with discretion due to the potential risks of tumor progression and peritoneal dissemination.

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.

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.

Pulmonary Carcinosarcoma: A Rare Disease With Challenging Diagnosis and Treatment

Pulmonary carcinosarcoma (PCS) is a rare type of non-small cell cancer. Overall, middle-aged and older smokers are the most affected age and sex groups. The diagnosis of PCS is difficult due to the absence of characteristic imaging findings. Additionally, preoperative biopsies do not usually reflect the heterologous nature of this tumor. Given the rarity of such tumors and the challenging diagnosis, the prognostic factors have not been established, and the overall prognosis remains poor. The valid therapeutic options are still limited. Here, we report a rare case of metastatic PCS that was accidentally discovered by imaging and properly diagnosed after surgical resection. The clinicopathological features, diagnostic tools, genetic theories, prognosis, and therapeutic options of this rare cancer are also discussed.

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.

An anaplastic lymphoma kinase (ALK) fusion oncogene positive metastatic sarcomatoid carcinoma of the lung with good response to crizotinib

Primary sarcomatoid carcinoma (SC) of the lung is a rare tumor that accounts for less than 1% of all lung cancers and compared to other non-small cell lung cancers (NSCLC) they appear more aggressive with poorer prognosis and response to treatment. Carcinosarcoma is one of the subtypes of SC. We report a case of carcinosarcoma with ALK-EML4 fusion gene in a 50-year-old male patient with a good response to therapy with crizotinib. An ALK rearrangement is a rare finding in SC, but as this case demonstrates, it may occur and it is necessary to perform the ALK testing in these tumors to find possible targeted treatments for better outcomes.

Carcinosarcoma of the ampulla of Vater: a case report and literature review

Background

Carcinosarcoma of the ampulla of Vater is extremely rare, and to the best of our knowledge, this is the third reported study.

Case presentation

The patient was a 73-year-old man, who presented with a chief complaint of dark urine. After a work-up, we suspected duodenal papillary cancer and performed a subtotal stomach-preserving pancreaticoduodenectomy with lymph node dissection. Immunohistochemically, the sarcomatous atypical cells were diffusely positive for cytokeratin AE1&3 and vimentin and focally positive for α-smooth muscle actin; these cells were also negative for desmin, CD34, DOG1, c-kit, and S100. From these findings, we diagnosed the patient with so-called carcinosarcoma. There was no lymph node metastasis.

Conclusions

Carcinosarcoma of the ampulla of Vater has a poor prognosis, and lymph node metastases are often seen. For the complete cure of carcinosarcoma of the ampulla of Vater, resection with the dissection of the lymph nodes may be necessary.

Key Features in the Management of Pulmonary Carcinosarcoma

Pulmonary carcinosarcoma represents a category of extremely rare tumours accounting for 0.1% of all lung malignancies. It is defined as a poorly differentiated non-small-cell carcinoma that contains a component of sarcoma or sarcoma-like elements. These biphasic tumours typically have a poor prognosis due to late diagnosis and early metastases. Preoperative tissue diagnosis is usually difficult due to the heterogeneity of the tumour, with biopsies often just reflecting one element of the tumour. By means of a case illustration and review of the literature, we discuss the optimal management of patients with pulmonary carcinosarcoma.

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.

Evaluation of six patients with pulmonary carcinosarcoma with a literature review

Background. Carcinosarcoma of the lung is a rare malignant neoplasm. We evaluated the diagnosis and treatment of six carcinosarcoma cases, including a synchronous tumour and a solitary pulmonary tumour, along with the clinical and histological features and survival times. Methods. From a retrospective analysis of 1076 non-small-cell lung cancer resections performed between January 1996 and January 2011, six patients (0.5%) with pulmonary carcinosarcoma (all males; mean age 58 years; range 53–66) who underwent surgical treatment were studied. Results. The mean tumour pathological T diameter was 7.2 cm (median 6 cm, range 3–14.5 cm). Only one patient was diagnosed with carcinosarcoma preoperatively. The clinical presentation and tumour localisations differed. The operations performed were a lobectomy (n = 4), pneumonectomy (n = 1), and bilobectomy (n = 1). Histologically, the epithelial characteristics of the tumours were consistent with squamous cell carcinoma in most of the patients. A complete resection was performed in all six patients. No mortality occurred in the early postoperative period. The median survival time was 9 (3–25) months. Conclusion. The preoperative diagnosis of carcinosarcoma of the lung is difficult due to the composition of the different histopathological structures. Complete surgical resection is the treatment of choice for pulmonary carcinosarcoma, although further studies are needed.

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.

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.

Lung carcinosarcoma as a rare biphasic sarcomatoid carcinoma: a case report

INTRODUCTION

A fit, 57-year-old man admitted with chest pain and haemoptysis turned out to have a primary tumour in the left lung.

CASE PRESENTATION

In this 57-year-old Caucasian man, the diagnosis followed a computed tomography scan and histopathological evidence gained post-resection. The biopsy showed a uniform, spindle shape with focal pleomorphism which was suggestive of lung carcinosarcoma.

CONCLUSIONS

The authors report this case in literature and discuss how a rare malignant tumour can be found in those presenting with trivial chest symptoms.

Carcinosarcoma of the gallbladder producing alpha-fetoprotein and manifesting as leukocytosis with elevated serum granulocyte colony-stimulating factor: report of a case

A 69-year-old man was referred to our hospital for investigation of leukocytosis and a persistent fever of 38 degrees C, but we could find no evidence of a specific infection. The leukocyte count was 18,000/mm(3), and the serum granulocyte colony-stimulating factor (G-CSF) and alpha-fetoprotein (AFP) levels were both elevated, at 66.3 pg/ml and 1,495 ng/ml, respectively. Computed tomography (CT) showed a gallbladder tumor and we performed extended cholecystectomy. Postoperatively, the fever subsided and the leukocyte count, serum G-CSF and AFP level normalized. Histologically, the tumor was a carcinosarcoma of the gallbladder. Immunohistochemical staining of the tumor cells was positive for AFP, but negative for G-CSF. This is the first report of a carcinosarcoma of the gallbladder producing AFP. The laboratory findings and clinical course strongly suggested that the tumor produced not only AFP, but also G-CSF.

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.

Pleomorphic carcinoma of the lung: clinicopathologic characteristics of 70 cases

Pleomorphic carcinoma (PC) of the lung is rare, and it is classified as a subtype of sarcomatoid carcinoma of the lung in the World Health Organization histologic classification of lung tumors. In this study, 70 cases of PC surgically resected were reviewed to identify its clinicopathologic characteristics. There were 57 men and 13 women, and their mean age was 66 years (range: 29 to 80 y). Sixty-eight tumors contained identifiable epithelial components, and the other 2 consisted of spindle cells and giant cells alone. An adenocarcinoma component was found in 34 cases, a squamous cell carcinoma component in 13, and a large cell carcinoma component in 40. The overall survival rate and disease-free survival rate were 36.6% and 40.7%, respectively, and both rates were significantly lower than for other nonsmall cell lung carcinomas. When the PC patients were divided into 3 groups according to the predominant epithelial component, an adenocarcinoma group, squamous cell carcinoma group, and large cell carcinoma group, there were no significant differences in the overall survival rate and median survival time between the 3 groups. Univariate analysis revealed that advanced stage (stage III), mediastinal lymph node metastasis, lymphatic permeation, and histologically diagnosed massive coagulation necrosis (>25% of the tumor) predicted poorer disease-free survival. Multivariate analysis showed that massive necrosis alone was an independent prognostic factor. We concluded that PC should be considered as an aggressive disease and massive necrosis should be routinely reported and used as a factor in clinical assessments.

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.

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.

So-called "inflammatory leiomyosarcoma'': a series of 3 cases providing additional insights into a rare entity

Inflammatory leiomyosarcoma, a rare entity first described in 1995, has been characterized by smooth muscle differentiation, a near-haploid karyotype, and a surprisingly good prognosis. The morphology is similar to that of conventional leiomyosarcoma admixed with a chronic inflammatory infiltrate. Thus far, only 15 cases have been reported in the English language literature. We report the clinical and pathological features of 3 additional cases of inflammatory leiomyosarcoma. Two women (ages 64 and 25, respectively) and 1 man (age 32) presented with a thigh, ovary, and lung mass, respectively. Inflammatory symptoms, such as anorexia, fever, night sweats, abdominal pain, and diarrhea, coincided with the thigh and ovarian primaries. Immunohistochemical studies revealed diffuse positivity for desmin and poor expression for other smooth muscle and skeletal muscle markers (muscle-specific actin [0/3], alpha-smooth muscle actin 1/3 [focal], calponin [1/3], caldesmon [0/3], and myogenin [0/3]). CD68 was diffusely positive in both the histiocytes and spindle cell component in all cases. Ultrastructural evaluation of 1 case (lung primary) lacked definitive smooth muscle differentiation. Cytogenetic analysis in 1 of 2 cases that were karyotyped, identified a near-haploid karyotype, which has been reported in other cases of inflammatory leiomyosarcoma. The other case showed 2 clonal populations of cells with interstitial deletions of the short arm of chromosome 8 and the long arm of chromosome 9, respectively. The case without cytogenetic data was intimately associated with an ovarian mature teratoma. These data also suggest that inflammatory leiomyosarcoma may lack smooth muscle differentiation, characterized by diffuse immunoreactivity for desmin but lack of immunoreactivity for alpha-smooth muscle actin, calponin, and caldesmon. In addition, 2 of the 3 cases developed distant metastases to the lungs, which suggests that these lesions may have a worse prognosis than previously believed.

Primary bone carcinosarcoma: Chondrosarcoma and squamous cell carcinoma with keratin pearl formation

Malignant bone tumors with epithelial differentiation are extremely rare. Only one case of primary malignant bone tumor with distinct squamous cell carcinoma and chondrosarcoma has ever been reported. Reported herein is a case of primary malignant bone tumor with distinct squamous cell carcinoma and chondrosarcoma, so-called carcinosarcoma of bone, arising in the femur of a 53-year-old man. The tumor was located within the femur and was diagnosed by curettage as a well-differentiated chondrosarcoma. No primary tumor was detected in any other organ. Within a few months the tumor had rapidly grown toward the soft tissue, and hemipelvectomy was performed. Examination of the surgical specimen revealed that the tumor was mainly composed of undifferentiated spindle sarcoma cells with scattered foci of chondrosarcoma and of squamous cell carcinoma with keratin pearl formation. The patient died approximately 6 months postoperatively. At autopsy multiple metastases were detected in the heart, both lungs, muscles, and lymph nodes. Interestingly, the chondrosarcoma and squamous cell carcinoma components were observed in several metastatic foci. The tumors in both the previously reported case and the present case contained components of chondrosarcoma and squamous cell carcinoma with keratin pearl formation, and this combination of histological features may be a unique characteristic of carcinosarcoma of bone.

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.

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.

Pulmonary pleomorphic (spindle) cell carcinoma: peculiar clinicopathologic manifestations different from ordinary non-small cell carcinoma

Pleomorphic (spindle) cell carcinoma, also known as monophasic sarcomatoid carcinoma, is a rare primary pulmonary malignancy. This type of tumor shows concurrent presence of malignant epithelial and homologous sarcomatoid spindle cell components by co-expressing cytokeratin and vimentin in various degrees. Sixteen cases (four central endobronchial lesions and 12 peripheral parenchymal masses) were studied clinicopathologically. Men were affected far more frequently than women (13:3). The patients were between 56 and 80 years of age. The disease is strongly associated with smoking. Among seven of the patients who underwent surgical resection, four of them had mediastinum, pleura and chest wall invasions, and three of them had regional lymph node metastases. All of the patients succumbed to early distant metastases (range 2 weeks-5 months) in organs including brain, bone, adrenal gland, and unusual sites such as esophagus, jejunum, rectum and kidney. The remaining nine inoperable cases were late stage disease and treated with chemoradiotherapy with little effect. The median duration of survival was 3 months. All parenchymal masses appeared as cavities with marked central necrosis, and only peripheral rim of tumor cells was left. More definite diagnostic results will depend on further tissue sections and can be confirmed by immunohistochemical studies. Significantly fewer Ki-67, p53 and c-erb B-2 oncoprotein expressions were also noted.

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.

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.

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.

Monoclonal origin of an esophageal carcinosarcoma producing granulocyte-colony stimulating factor: a case report

BACKGROUND

Carcinosarcomas are comprised of carcinomatous and sarcomatous elements, and their histogenesis remains unclear. The authors examined the serum concentrations of hematopoietic growth factors and performed immunohistochemical studies on an esophageal carcinosarcoma from a patient with marked granulocytosis to determine its histopathogenesis and clonality.

METHODS

The authors examined the case of a 63-year-old man with a polypoid tumor of the esophagus associated with marked leukocytosis (131 x 10(9) per liter). Immunohistochemical staining of the esophageal tumor was performed using monoclonal antibodies against granulocyte-colony stimulating factor (G-CSF), keratin, epithelial membrane antigen (EMA), and vimentin.

RESULTS

The patient's leukocyte count was increased (124 x 10(9) per liter) on admission. Because mature granulocytes predominantly were increased despite the absence of apparent infection, the patient's serum G-CSF concentration was examined and found to be 286.0 pg/mL and to increase with time. After thoracic esophagectomy was performed, granulocyte count and serum G-CSF concentration rapidly normalized. G-CSF concentration was 50-fold higher in the tumor tissue extract than in the extract from normal esophageal tissue. Microscopic examination of the resected specimens revealed that the tumor was comprised of squamous cell carcinoma (SCC) and spindle-shaped sarcomatous elements, and transitional features were observed within these two components. Immunohistochemical examination disclosed cells that were positive for keratin and EMA in the carcinomatous element and vimentin positive cells in the sarcomatous element. However, both types of tumor cells were positive for G-CSF.

CONCLUSIONS

The presence of G-CSF in both SCC cells and spindle-shaped sarcomatous cells indicated that these two components originated from a single clone.

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.

Sarcomatoid carcinomas: pathological and histopathogenetic considerations

Malignant tumors with a mixed phenotype are a controversial field of pathology. In this article the morphological aspects and the immunohistological characterization of sarcomatoid carcinomas are presented. These uncommon neoplasms show both carcinomatous and sarcomatous features, and have been described in the past under a variety of different names causing great uncertainty about their classification and histogenesis. They can occur in various anatomical sites and exhibit a wide range of microscopic appearances, but some features are quite characteristic and are found in many cases. Morphological "transition" between carcinomatous and sarcomatous tissue, and detection of epithelial characteristics by electron microscopy or immunohistochemistry in the sarcomatous component, are very peculiar features of these neoplasms, providing both helpful clues for pathological diagnosis and important insights into histogenesis. Here a unifying histopathogenetic mechanism based on the phenotypic conversion of carcinoma into sarcomatoid tissue is proposed and supporting literature data from both experimental systems and clinicopathological observations are reviewed and discussed.

Sarcomatoid carcinoma of the small intestine: histologic, immunohistochemical and ultrastructural features of three cases and its differential diagnosis

Three cases of sarcomatoid carcinoma of the small intestine are presented. One of them was found accidentally in the duodenum of a patient with a well differentiated adenocarcinoma and a malignant lymphoma that were limited to the stomach. The other two cases arose from the ileum. All of the tumors were whitish, soft and ulcerated with focal hemorrhage and necrosis and showed expansive growth. Each tumor consisted of a mixture of polygonal and spindle shaped anaplastic neoplastic cells arranged in sheet, short fascicular or haphazard fashion, with no finding suggesting epithelial differentiation. Special stains demonstrated intracellular mucin in only a small number of tumor cells in two cases, but not in the other case. Immunohistochemically, the tumor cells of two cases at both primary and metastatic sites showed a positive immunoreaction for cytokeratin and epithelial membrane antigen. In the other case, only a few tumor cells at the metastatic site, but not at the primary site, showed cytokeratin positivity. Various numbers of tumor cells positive for vimentin, alpha-1-antitrypsin (AAT), alpha-1-antichymotrypsin (ACT) and KP-1 were detected in each case. Ultrastructurally, some populations of tumor cells possessed various amounts of tonofilaments with a few intercellular connections between adjacent tumor cells. These cases should be classified as sarcomatoid carcinoma of the small intestine, despite partial or complete loss of epithelial features, and distinguished from the various sarcomas.

Spindle cell hepatocellular carcinoma. A clinicopathologic and immunohistochemical analysis of 15 cases

BACKGROUND

Spindle cell hepatocellular carcinoma (SpHCC) has rarely been reported, and its clinicopathologic characteristics, histogenesis, and prognosis after hepatic resection have yet to be clarified.

METHODS

Fifteen cases of SpHCC, including 13 surgically resected patients and 2 autopsy cases, were studied clinicopathologically and immunohistochemically.

RESULTS

In 13 resected patients, all except 1 were male and the serum alpha-fetoprotein (AFP) was positive in 6 (46%). Portal venous invasion and intrahepatic metastases were frequent. In an immunohistochemical analysis of 13 SpHCC tumors, cytokeratin CAM 5.2 and AFP were positive in 8 (62%) tumors and 3 (23%) tumors in both ordinary HCC and spindle cell components, respectively. The spindle cell components, but not ordinary HCC components, revealed a positive reaction for vimentin in 8 (62%) tumors, S-100 protein and HAM-56 in 3 (23%) tumors, HHF-35 in 2 (15%) tumors, and alpha-smooth muscle actin, desmin, and KP-1 in 1 (8%) tumor, respectively. p53 overexpression was found in two SpHCC tumors. The survival curve after hepatic resection in the 13 patients with SpHCC was significantly worse than that of the 371 patients with Stage II-IV ordinary HCC (P < 0.001).

CONCLUSIONS

These results suggest that SpHCC represents a sarcomatous transformation of HCC. The spindle cell components revealed an immunohistochemical expression of several markers of mesenchymal cells. In addition, poor survival after hepatic resection was documented.

Alteration of the p53 gene of lung carcinomas with sarcomatous transformation (spindle cell carcinoma): analysis of four cases

Lung carcinoma with sarcomatous transformation (LCST) is highly aggressive and characterized by local invasion and/or distant metastasis, which leads to a shorter survival than ordinary lung carcinomas. Therefore, to elucidate whether the malignant potential of the spindle cell element in LCST is associated with the alteration of the p53 gene, four cases were examined by analyses of overexpression of the p53 oncoprotein, mutation of the p53 gene and loss-of-heterozygosity (LOH) at chromosome 17p. In two cases overexpression of the p53 oncoprotein of the spindle cell component showed a higher degree of staining than that of the carcinoma component; LOH was identified in both carcinoma and sarcomatous components in one case, while in contrast, another case showed LOH in the sarcomatous component only. Mutations were clearly detected in two cases; one showed a CTT to CGT transversion in codon 194 of exon 6 in both components, whereas the other showed a CTG to CAG transversion in codon 265 of exon 8 in the sarcomatous component only. On the basis of these observations, it suggested that the sarcomatous component shows a higher frequency of p53 gene abnormalities in comparison to the carcinoma component. These results also suggested that the acquisition of malignant potential in the sarcomatous component, or the morphological alteration of carcinoma cells, is correlated with abnormalities associated with the p53 gene.

Sarcomatoid carcinoma: an ultrastructural study with light microscopic and immunohistochemical correlation of 10 cases from various anatomic sites

The histogenesis of sarcomatoid carcinoma has been an intriguing topic for pathologists for many years, and considerable evidence has accumulated in the fields of tissue culture, electron microscopy, and immunohistochemistry to support the concept that the sarcomatous cells derive by way of "divergent differentiation" (metaplasia) from the carcinomatous elements. We have studied a group of 10 cases of these tumors from various organs, using detailed ultrastructural analysis as well as light microscopic and immunohistochemical correlation. We found that there is an ultrastructural spectrum of differentiation from epithelial to mesenchymal type features and that the malignant spindle cells may be purely epithelial (3 cases), purely mesenchymal (3 cases), or a mixture of both (4 cases). Furthermore, individual cells may show biphasia, having desmosomes and tonofibrils as well as well developed rough endoplasmic reticulum and filaments with dense bodies. Electron microscopic and immunohistochemical results do not always correlate, illustrating the prudence of using several keratin antibodies, including wide-spectrum ones, and of performing electron microscopic examination on these tumors.

Mixed pulmonary blastoma and carcinosarcoma

Pulmonary blastomas and carcinosarcomas are uncommon tumours, accounting for less than 1% of all lung neoplasms. Three previously described mixed epithelial and mesenchymal tumours having both adult and embryonal elements were termed 'transitional'. We report a similar case and evaluate the application of the term 'transitional tumour'.

Pleomorphic (spindle/giant cell) carcinoma of the lung. A clinicopathologic correlation of 78 cases

BACKGROUND

The authors undertook this study to define the clinical and histologic characteristics of spindle and giant cell carcinomas of the lung and the survival and prognostic features of these tumors.

METHODS

Seventy-eight cases of pleomorphic (spindle and/or giant cell) carcinoma of the lung were studied by light microscopy and immunohistochemistry to establish clinical, gross, and histologic parameters. Follow-up information was obtained from contributing physicians and analyzed by statistical means to determine prognostically significant parameters.

RESULTS

The patient population consisted of 57 men and 21 women (male to female ratio, 2.7 to 1) between the ages of 35 and 83 years (mean, 62 years). Clinically, 58 patients (80%) presented with symptoms including thoracic pain, cough, and hemoptysis, whereas 14 (18%) were asymptomatic. At the time of diagnosis, 41% of the patients had clinical Stage I lesions, 6% Stage II lesions, 39% Stage III lesions, and 12% Stage IV lesions. Histologically, foci of squamous cell carcinoma were present in 8% of the tumors, large cell carcinoma in 25%, and adenocarcinoma in 45%. The remaining 22% of neoplasms were completely spindle and/or giant cell carcinomas. Spindle and giant cell carcinomas were found together in 38% of the patients. In the 69 patients for whom follow-up information was obtained, 53 (77%) died within 7 days to 6 years after diagnosis, with a 23-month mean survival (median, 10 months) (Kaplan-Meier method). There was a significant shortening of survival for patients with tumor size greater than 5 cm, clinical stage greater than 1, and lymph node involvement. The presence of nodal metastases was the most significant single prognostic factor, whereas the presence of squamous or adenocarcinomatous differentiation did not have an impact on length of survival.

CONCLUSIONS

The frequency with which spindle and giant cell carcinomas are found together, their frequent association with other histologic subtypes of lung carcinoma, and the similar clinicopathologic features of these tumors suggest that they are best regarded as one type of lung cancer called pleomorphic carcinoma.

Immunohistochemical profile of synovial sarcoma with emphasis on the epithelial-type differentiation. A study of 49 primary tumours, recurrences and metastases

The relationship between biphasic (BSS) and monophasic (MSS) subtypes of synovial sarcoma (SS) as well as the relationship between cells of solid/glandular areas and the spindle cells of BSS remain controversial. In order to further evaluate the immunohistochemical phenotype of SS we studied 34 primary tumours (15 BSS; 19 MSS), 7 recurrences (4 from primary BSS; 3 from primary MSS) and 8 metastases (7 BSS; one MSS), using several antibodies (EMA, CEA, keratins 1, 4, 5/6, 7, 8, 13, 18, 19, 20, vimentin, collagen IV and laminin) that work in paraffin-embedded material. Spindle cells outside solid/glandular areas of BSS and in MSS showed immunoreactivity for keratins 5/6, 7, 8, 18 and 19. The transition of solid/glandular areas to surrounding spindle cells also showed keratin staining and failed to show a distinct separation regarding the immunoreactivity for laminin and collagen IV. Peripheral cells of solid/glandular areas were immunoreactive for vimentin. No major differences were observed between immunophenotypical cell profiles of BSS and MSS, apart from the exclusive immunostaining of solid/glandular areas of BSS for keratin 13 and CEA. Downgrading of keratin and extracellular matrix antigens immunoreactivity was observed when primary tumours were compared to recurrent and/or metastatic tumours of both subtypes (MSS and BSS). We conclude that SS should be regarded as carcinomas of soft tissues with an immunohistochemical phenotype depending on the degree of epithelial differentiation: spindle cells (MSS and BSS) predominantly expressing simple keratins, and poorly differentiated (solid/glandular) as well as well-differentiated (glandular) areas (BSS) expressing, in addition, complex epithelial-type keratins.

Undifferentiated spindle cell carcinoma of the gallbladder: a clinicopathologic, immunohistochemical, and flow cytometric study of 11 cases

Eleven primary spindle cell carcinomas (SpCCs) of the gallbladder are reported. They occurred in eight women and three men ranging in age from 59 to 80 years (mean age, 66.5 years). Histologically, the tumors showed interlacing bundles of atypical spindle cells with eosinophilic cytoplasm, oval to elongated nuclei, and conspicuous nucleoli. Eight SpCCs contained tiny foci of neoplastic glands similar to those seen in adenocarcinoma, and two of these cases also had small foci of neoplastic squamous epithelium. A gradual transition between the squamous cell carcinoma and the spindle cell component was observed in one tumor. Immunohistochemically, all SpCCs were positive for at least one of the epithelial markers (epithelial membrane antigen, nine cases; AE1/AE3, nine cases; carcinoembryonic antigen, three cases; and EAB 903, one case), and the tumor cells also were immunoreactive to mesenchymal marker (vimentin, eight cases), muscle markers (alpha-smooth muscle actin, one case; desmin, one case), and histiocytic marker (HAM 56, one case). Abnormalities in tumor suppressor gene p53 expression also were found in two of the 11 SpCC cases using monoclonal antibody PAb 1801. In six cases for which data were available flow cytometry revealed aneuploidy in three SpCCs (50%). The survival curve of the SpCC cases (mean survival, 9 months) was less favorable than that of 224 cases of adenocarcinoma of the gallbladder (mean survival, 81 months) (P = .0011). These results indicate that SpCC of the gallbladder is an epithelial tumor with sarcomatoid components and its prognosis is unfavorable.