Transthoracic fine-needle aspiration biopsy of pulmonary spindle cell and mesenchymal lesions: a study of 61 cases

Cytopathology of solitary fibrous tumor: a series of 34 cases

INTRODUCTION

Solitary fibrous tumor (SFT), a fibroblastic neoplasm characterized by a specific genetic alteration (NAB2-STAT6 fusion) and relatively specific immunohistochemical profile (STAT6/CD34 positivity), is seldom the subject of cytopathology data. We report our experience with scrape smears and fine-needle aspiration (FNA) biopsies of SFT in a large patient cohort.

MATERIALS AND METHODS

A search was made of our cytopathology and surgical pathology databases for cases diagnosed as solitary fibrous tumor (SFT). FNA biopsy smears, imprint smears, and cell blocks were performed and examined using standard technique.

RESULTS

Thirty-four cases from 30 patients (M:F = 1.1:1; age range: 24-86 years, x = 58 years) met inclusion criteria for this study. All patients had prior or subsequent tissue confirmation of SFT. Twenty-seven (79%) specimens were FNAs, and 7 (21%) were scrape smears. Most cases (29, 85%) represented primary tumors, 4 (12%) were metastatic deposits, and 1 (3.5%) was a locally recurrent neoplasm. Sites included: pleura/lung 9 (26%), head/neck 8 (24%), lower extremity 7 (21%), trunk 4 (12%), intra-abdominal 3 (9%), upper extremity 2 (7%), and mediastinum 1 (4%). Mean tumor size was 7.2 cm (range: 1.5-19 cm). Three (9%) cases were diagnosed specifically as SFT. Remaining diagnoses were spindle cell neoplasm/proliferation 14 (41%), nondiagnostic 5 (15%), specific type of sarcoma 3 (9%), malignant round cell tumor 2 (6%), sarcoma 2 (6%), malignant tumor 2 (6%) and single cases of melanoma, pleomorphic adenoma, and mesenchymal tumor. Immunohistochemical (IHC) testing was performed in 7 of 27 (26%) cell blocks.

CONCLUSION

SFT FNA cytopathology is morphologically ambiguous, overlapping with a broad array of other spindle cell proliferations. A specific diagnosis is only possible with added staining of STAT6 coupled with a set of other IHC markers.

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.

Surgical treatment and outcome of pulmonary hamartoma: a retrospective study of 10-year experience

Background

The present retrospective study was designed to review the clinicopathological features and outcome of surgical treatment of pulmonary hamartoma who underwent surgical operation between January 2008 and January 2018.

Methods

The information about the age and gender of patients, symptoms, history of tobacco consumption, the presence of malignancies, radiological and imaging findings, calcification in the hamartoma, location and size of the lesions, findings of preoperative diagnostic investigations, operative procedures, operative time, tube drainage duration, surgical complication, hospital stay after tumor resection, duration of follow-up, and outcome were recorded.

Results

The average size of the neoplasms was 2.72 cm. Five patients (20.8%) had malignancies, which occurred previously in two patients, and concomitantly in three patients. Twenty-four patients underwent surgical treatment which included enucleation in 14 (four cases had thoracoscopic surgery), wedge resection in 8 (six cases had thoracoscopic surgery), and lobectomy in 2 patients. A total of four postoperative complications were noted. The patients were followed up for 2-98 months.

Conclusion

Enucleation was the main choice in our series. The follow-up for a long period revealed no malignant transformation and recurrence. Due to lack of the malignance after operation in our series, we presumed that the enucleation for pulmonary hamartoma was safe enough.

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.

Combined small cell carcinoma with giant cell carcinoma component of the lung: A case successfully diagnosed by computed tomography-guided fine-needle aspiration cytology

Combined small cell lung carcinoma (SCLC) is a rare variant of SCLC and is defined as a mixture of SCLC and non-SCLC components. Although any histopathological subtype may be present as a non-SCLC component, the presence of pleomorphic carcinoma components are extremely rare. The present report describes the first documented cytological features of combined SCLC with a giant cell carcinoma component. A 50-year-old Japanese female with a history of smoking presented with a mass lesion in the left lung. Computed tomography-guided fine-needle aspiration cytology and needle biopsy were performed, followed by a lobectomy. A Papanicolaou smear revealed the presence of two distinct neoplastic components in a necrotic background. One component was SCLC, which comprised small-sized neoplastic cells containing scant cytoplasm and round to oval nuclei with dispersed granular chromatin without nucleoli. The other component was giant cell carcinoma, which was composed of large-sized neoplastic cells containing irregular large hyperchromatic nuclei (approximately 7 to 10 times larger than those of SCLC). SCLC was demonstrated in the biopsy specimen, however no giant cell carcinoma component was present. Histopathological study of the lobectomy specimen verified a diagnosis of combined SCLC with giant cell carcinoma component. Both SCLC and giant cell carcinoma exhibit characteristic cytological features, therefore, albeit extremely rare, careful observation may lead to a correct diagnosis of combined SCLC in the cytological specimen.

The efficacy of transbronchial needle aspiration with endobronchial ultrasonography using a guide sheath for peripheral pulmonary lesions suspected to be lung cancer

BACKGROUND

The efficacy of transbronchial needle aspiration (TBNA) with endobronchial ultrasonography using a guide sheath (EBUS-GS) for cases of peripheral pulmonary lesions (PPLs) has not been well established. The purpose of this study was to evaluate the efficacy of TBNA with EBUS-GS for PPLs.

METHODS

We evaluated 130 patients suspected to have lung cancer who underwent transbronchial brushing (brushing), transbronchial biopsy (TBB), and TBNA with EBUS-GS. The pathological diagnostic yields of TBNA were compared to that of TBB and brushing. The histological diagnosis of TBNA was compared to that of surgical specimens. The results of epidermal growth factor receptor (EGFR) gene mutation in TBNA samples were compared to that in TBB or surgical specimens.

RESULTS

The diagnostic yields of this study were 62.9% for brushing, 80.0% for TBB, and 77.1% for TBNA. Histological diagnosis was 84.8% for TBB and/or TBNA and pathological diagnosis was 86.7% for all the procedures. TBB and TBNA had significance higher than brushing (p < 0.05). TBB and TBNA had a tendency of higher diagnostic yields than brushing if EBUS probe was adjacent to PPLs (p = 0.058). Histological evaluations were obtained from TBNA specimens from 50 of 105 patients (47.6%) and these were identical to those of surgical specimens from 29 of 32 patients (90.6%). The results of EGFR gene mutation in TBNA specimens were identical to the same tissue obtained by surgery or TBB.

CONCLUSIONS

TBNA with EBUS-GS for PPLs was a useful tool for accurate diagnosis and EGFR gene mutation analysis. This method may improve diagnostic accuracy and be useful for molecular testing. This study was approved by the institutional review board (Date of approval: May 27, 2013, approval number: 2816) of Tokyo Women's Medical University Hospital.

Pulmonary hamartoma: Cytological study of a case and literature review

Pulmonary hamartomas are the most common but rare benign tumor-like lesions of the lung arising from the embryonic rest. They are more common in males and in aged. Majority are asymptomatic and seen as coin lesions with popcorn calcification in the chest radiograph. Fine needle aspiration cytology (FNAC) helps to diagnose and distinguish them from the cancerous lesions of the lung. The cytological material is characterized by fibromyxoid stroma, cartilage, bronchial cells, adipose tissue and bone. Bronchial cells with reactive atypia may be a source of false-positive result. Symptomatic cases need surgical intervention such as enucleation or segmental resection. We report a case of a 74-year-old male who had a lung mass that did not progress over 4-year on chest radiograph. The CT-guided FNAC smears showed benign bronchial epithelial cells, fibro-myxoid spindle cell stroma and fat spaces that aided the diagnosis of pulmonary hamartoma avoiding surgical intervention.

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.

A rare case of hypoglycemia in a patient with elevated right hemidiaphragm

A 57-year-old woman was admitted to the emergency department, presenting with episodes of altered consciousness and behaviour which, upon further examination, were linked to periods of recurrent hypoglycaemia. Imaging revealed a large mass in the right thoracic cavity while blood analysis demonstrated diminished C-peptide, (pro-)insulin, insulin-like growth factor 1 (IGF-I) and IGF binding protein 3 levels. Based on these findings, an IGF-II secreting tumour was suspected. Before the excision of the tumour, euglycaemia could only be achieved by means of intravenous glucose administration and the use of oral corticosteroids. Anatomopathologically the diagnosis of a solitary fibrous tumour (SFT) was confirmed. Immunoblot analysis on the serum revealed elevated 'big'-IGF-II levels, confirming our initial diagnosis of Doege-Potter syndrome in SFT.

Respiratory Tract and Mediastinum

Normal cytology, abnormal and atypical cells, non-cellular components, and infectious cell changes are largely described together with benign, malignant, and neuroendocrine lesions regarding exfoliative and aspiration cytology of the lung. A separate section broadly addresses diagnostic findings and differential diagnoses in bronchoalveolar washings.

The section ‘Fine needle aspiration biopsy of mediastinal disorders’ covers in particular biopsy techniques, accuracy of liquid-based cytology, and the complex lesions of the thymus gland. Cytodiagnostic algorithms of the major benign and malignant pulmonary and mediastinal lesions and their respective differential diagnoses are additionally presented in synoptic setups.

Clinicopathological and immunohistochemical analysis of spindle-cell carcinoid tumour of the lung

AIMS

To analyse the clinicopathological features and immunohistchemical profile of spindle-cell carcinoid tumours (SCCT) of the lung.

METHODS AND RESULTS

Using a cut-off value of ≥ 50% spindle cells for defining SCCT, 13 were indentified among 80 consecutively resected carcinoid cases. SCCTs are asymptomatic and are peripherally located, well-demarcated tumours. Tumour cells were composed of elongated spindle cells, with scant to moderate amounts of cytoplasm and uniform nuclei with fine granular chromatin. Immunohistochemical analysis revealed that all 13 cases were positive for three neuroendocrine markers (chromogranin A, synaptophysin and CD56). Four tumours (30.7%) were positive for broad-spectrum cytokeratin (CK) and nine tumours (69.2%) were positive for thyroid transcription factor 1. All epithelial components were negative for vimentin, but 12 tumours (92.3%) were positive for stellate-shaped cells (so-called sustentacular cells).

CONCLUSIONS

SCCTs are clinically asymptomatic, peripherally located, well-demarcated tumours, and patients with SCCTs have a favourable outcome. The immunoreactivity pattern of SCCT (low reactivity of broad-spectrum CK and reactivity for vimentin in intratumoral sustentacular cells) might result in a misdiagnosis of SCCT as mesenchymal tumour; therefore, pathologists need to be familiar with this pattern.

Solitary fibrous tumor of the central nervous system: a 15-year literature survey of 220 cases (August 1996-July 2011)

We reviewed the world literature on solitary fibrous tumors of the central nervous system from August 1996 to July 2011, focusing on both clinicopathological features and diagnostic findings. The anatomical distribution of the 220 cases reported so far reveals that most are intracranial and just over one-fifth are intraspinal. In decreasing frequency, intracranial tumors involve the supratentorial and infratentorial compartments, the pontocerebellar angle, the sellar and parasellar regions, and the cranial nerves. Intraspinal tumors are mainly located in the thoracic and cervical segments. Although most solitary fibrous tumors of the central nervous system are dural based, a small subset presents as subpial, intraparenchymal, intraventricular, or as tumors involving the nerve rootlets with no dural connection. Preoperative imaging and intraoperative findings suggest meningioma, schwannoma or neurofibroma, hemangiopericytoma, or pituitary tumors. Immunohistochemistry is critical to establish a definitive histopathological diagnosis. Vimentin, CD34, BCL2, and CD99 are the most consistently positive markers. The usual histologic type generally behaves in a benign manner if complete removal is achieved. Recurrence is anticipated when resection is subtotal or when the tumor exhibits atypical histology. The proliferative index as assessed by MIB1 labeling is of prognostic significance. Occasionally, tumors featuring conventional morphology may recur, perhaps because of minimal residual disease left behind during surgical extirpation. Rare extracranial metastases and tumor-related deaths are on record. Surgery is the treatment of choice. Stereotactic and external beam radiation therapy may be indicated for postsurgical tumor remnants and for unresectable recurrences. Long-term active surveillance of the patients is mandatory.

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.

Surgical treatment and outcome of pulmonary hamartoma: a retrospective study of 20-year experience

BACKGROUND

Controversy still exists in the indication and timing of surgical treatment of pulmonary hamartoma (PH). The objective of this study is to summarize the experience and the outcome of the surgical treatment for pulmonary hamartomas, and to assess the effectiveness and necessity of surgical therapy administered in patients with pulmonary hamartoma as well as clinical and pathological features and long-term follow-up results.

METHODS

This retrospective report has reviewed a 20-years clinical history of surgical treatment for 39 patients with PH from 1985 to 2006. These thirty-nine patients underwent 40 operations as follows: wedge resection (23), enucleation (10), segmentectomy (3), lobectomy (3), and pneumonectomy (1).

RESULTS

The PH occurred most frequently (78.1%) in the patients aged 40 to 60 years and the sex ratio (male/female) was 2.25/1 in our series. No postoperative death was encountered. One patient with pleural effusion was cured after thoracentesis. All of these 39 patients were proved with pathologic diagnosis of PH and the popcorn calcification was found in 6 cases before operation. In 38 cases having the mean follow-up of 7.3 years, a patient was operated thrice for regional recurrence.

CONCLUSION

Fast frozen section in operation is critical for acquire accurate pathological diagnosis. Due to potential trend of recurrence or malignancy, patients with hamartoma should be submitted to a complete evaluation and a regular follow-up.

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.

Carcinoma pleomórfico do pulmão em doente com síndroma de Mounier-Kuhn

Pleomorphic carcinoma of the lung (PLC) is a rare malignant tumour presenting with a poor clinical outcome. It is included in the group of non-small cell lung carcinomas that contain sarcoma or sarcoma-like components (spindle cells/giant cells). Because of its rarity and diagnostic difficulties, the authors report a case of PLC in a 44 year-old patient, smoker, with the initial clinical presentation of a dorsal tumoural mass. As the time of diagnosis the tumour was in stage IV (TNM), the patient was treated only with supportive therapy and died five months later. During clinical evaluation, a Mounier-Kuhn Syndrome was confirmed. Clinical-imagiological aspects of this situation are reported as well as cytological and immunocytochemical features.

Cytohistologic correlations in schwannomas (neurilemmomas), including "ancient," cellular, and epithelioid variants

Schwannoma accounts for one of the most common benign mesenchymal neoplasms of soft tissues. Although it is well defined in the cytology literature, particular histologic subtypes such as "ancient," cellular and epithelioid variants could be a source of diagnostic difficulties. We have reviewed cytology aspirates and corresponding histologic sections from 34 schwannomas diagnosed at Institut Curie. Histologically, 24 cases were classic, 5 were "ancient," 4 were cellular, and 1 was epithelioid schwannomas. No example of melanotic schwannoma was recorded. Original cytologic diagnosis was schwannoma in 13 (38.2%) cases, benign soft tissue tumor in 11 (32.4%), pleomorphic adenoma in 2 (6%) cases, angioma in 1 (2.9%) case, nodular fasciitis in 1 (2.9%) case, suspicious in 3 (8.8%) cases, and not satisfactory in 3 (8.8%) cases. There were no major differences between classical, "ancient," cellular, and epithelioid variants on cytology smears. Myxoid stroma, mast cells, and intranuclear inclusions were limited to classical subtype. Similarly, cyto-nuclear atypia was more frequent in classical subtype than in other subtypes. Schwannoma should be differentiated from well-differentiated malignant peripheral nerve sheath tumor, neurofibroma, and pleomorphic adenoma, in the last instance particularly for head and neck lesions.

Inflammatory pseudotumor: a diagnostic dilemma in cytopathology

Inflammatory pseudotumor (IPT) is a rare space-occupying lesion of unknown etiology that can mimic malignancy on clinicoradiological and pathological examination. A review of the cytopathology archives at The Johns Hopkins Hospital identified 12 cases from eight patients with histologically proven IPT (lung, seven patients; liver, five patients). There were six men and two women with an age range of 28-84 yr (mean age, 59 yr). Presenting complaints of IPT of the lung included shortness of breath and hemoptysis, and in cases of IPT of the liver complaints included abdominal pain and elevated liver function tests (LFTs). All cases were found to have mass lesions suspicious for a neoplasm on radiographic examination. Cytological specimens consisted of fine-needle aspiration (FNA; seven specimens) and bronchial brush/wash (five specimens). Diagnostic accuracy of cytology for IPT was low (5/12, 42%). IPT showed hypercellular smears (on FNA) with an admixture of various cell types including inflammatory cells with predominance of plasma cells, fibroblastic proliferation, granulation tissue formation, and atypical-appearing histiocytes with enlarged nuclei and intranuclear inclusions. Fibroblastic proliferation with mitoses may mimic mesenchymal neoplasms. Cytomorphology is nonspecific and IPT usually is a diagnosis of exclusion.

Cryptogenic organizing pneumonia

Cryptogenic organizing pneumonia is a rare, distinct disorder that is sufficiently different from the other diseases in the group of idiopathic interstitial pneumonias to be designated as a separate entity. In its most typical presentation, it is characterized by dyspnea and cough, with multiple patchy alveolar opacities on pulmonary imaging. Definite diagnosis is obtained by the finding of buds of granulation tissue in the distal airspaces at lung biopsy. No cause (as infection, drug reaction, or associated disease as connective tissue disease) is found. Corticosteroid treatment is rapidly effective, but relapses are common on reducing or stopping treatment.

Fine-Needle Aspiration of Pulmonary Hamartoma: A Common Source of False-Positive Diagnoses in the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology

Context.—We use data from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology to evaluate the accuracy of fine-needle aspiration (FNA) biopsy for diagnosing pulmonary hamartoma (PH).

Objective.—To use the performance characteristics of the PH cases in the Nongynecologic Cytology Program to determine the accuracy of FNA for identifying these lesions and to determine potential sources of interpretative errors.

Design.—A retrospective review of the College of American Pathologists Nongynecologic Cytology cumulative data from 1997 to 2003 was performed to identify the overall accuracy of FNA for diagnosing PH and to determine the most common interpretative pitfalls. The slides from each of the cases of PH in the Nongynecologic Cytology Program were then reviewed in an effort to identify the cytologic characteristics that contributed to the poor performance of these cases.

Results.—A total of 766 participant responses for 19 PH FNA specimens were reviewed. The specificity of FNA for making the correct general reference interpretation of benign was 78%. The false-positive rate was 22%, with the most common false-positive diagnoses being carcinoid tumor, adenocarcinoma, and small cell carcinoma. The overall accuracy for making the correct specific reference diagnosis of PH was 26%. Microscopic review of the individual cases revealed possible explanations for some of the interpretative errors and the most frequent false-positive interpretations.

Conclusions.—Cytologists should be aware of the potential false-positive interpretations that can occur in FNAs of PH and the potential reasons for these inaccuracies in order to minimize clinically significant diagnostic errors.

Monophasic synovial sarcoma: a cytologic spectrum

Synovial sarcoma (SS) is a high-grade sarcoma that can be diagnosed in cytology with certainty only when it presents with a biphasic pattern. Monophasic SS (MSS), however, is a diagnostic consideration when a uniform spindle cell population is present. The purpose of this study was to evaluate a series of cytologic cases of MSS and its cytologic presentation. Twenty-one FNAs of histologically confirmed MSS were reviewed. Specimens consisted of tissue fragments and single cells containing scant granular cytoplasm, medium-sized nuclei, and coarse chromatin. A monotonous spindle pattern with comma-shaped nuclei was present in 5 cases. Sixteen cases contained oval and spindled nuclei. Eight of these specimens contained round nuclei, and 5 of these cases showed prominent nucleoli and cohesive clusters, reminiscent of biphasic SS. We conclude that a spectrum of cytologic findings can be seen in MSS, including a secondary population of cells with morphology usually typical of biphasic SS.

Metastatic malignant solitary fibrous tumour to the infra-temporal fossa

Malignant solitary fibrous tumours (MSFTs) are rare tumours of fibrous origin, which can occur at all anatomical sites and represent 20% of solitary fibrous tumours. Fine-needle aspiration cytology is not able to distinguish benign from malignant disease, and sufficient tissue has to be obtained for accurate histological diagnosis to be made. Lesions > 10 cm in diameter and incomplete resection or non-resectability are predictive factors for poor long-term survival. We present a 57-year-old patient with a presumably metastatic MSFT from the peritoneal cavity to the skull-base who is in a stable state 17 months after surgical debulking of the skull-base and removal of the peritoneal lesion, followed by post-operative chemotherapy. We suggest the terminology metastatic malignant solitary fibrous tumour for a description of this disease.

Fine-needle aspiration of leiomyosarcoma: a correlative cytohistopathological study of 96 tumors in 68 patients

To better define the cytological features of various leiomyosarcoma (LMS) variants, we reviewed the fine-needle aspiration material and the corresponding histologic sections of 96 tumors in 68 patients. Histological variants of LMS were as follows: 80 (83.3%) were of the classical/usual, seven (7.3%) were epithelioid, and nine (9.4%) were myxoid. Review of original cytology reports showed that 23 (24%) tumors were diagnosed as LMS and 69 (71.8%) as other types of malignancies. Two (2.1%) cases were reported as suspicious and two (2.1%) were unsatisfactory. The classical variants of LMS were characterized cytologically by various proportions of spindle-shaped, cohesive, small- or large-sized cells arranged in parallel alignment. Large spindle, round, binucleated, giant cells with intracytoplasmic granulations were frequently seen. Blunt-ended nuclei, intranuclear inclusions and mitotic figures were occasionally seen, as well as stromal fragments. The epithelioid tumors were composed of an admixture of small and large, spindle-shaped and round cells, also arranged in parallel alignment. Tumor cells with granular cytoplasm, blunt-ended nuclei, intranuclear inclusions, mitotic figures, fibrous or myxoid stroma were not observed. The myxoid tumors disclosed large amounts of background myxoid matrix containing large spindle-shaped and giant cells. Entities such as leiomyoma, malignant peripheral nerve sheath tumor, monophasic synovial sarcoma, and malignant fibrous histiocytoma should be considered in the differential diagnosis of LMS of the classical type. Epithelioid leiomyoma may share similar cytological features with epithelioid LMS. The cytological features of the myxoid variant of LMS can be easily confused with other types of benign and malignant mesenchymal tumors depicting degenerative myxoid changes and/or a myxoid matrix component.

Cytologic analyses of spindle-cell lesions of the thorax and retroperitoneum

Thoracic and retroperitoneal spindle-cell lesions represent a diagnostic challenge in the evaluation of fine-needle aspiration (FNA) specimens. The challenge is due to the morphologic similarities and wide variety of different entities with spindle-cell morphology in these two sites. The purpose of this study was to identify criteria helpful in the classification and differential diagnosis of spindle-cell lesions in these two locations. A set of cytologic features was analyzed in 57 thoracic or retroperitoneal spindle-cell lesions. Our results show that pleomorphism and abundant single cells were parameters associated with high-grade tumors in univariate and multivariate analysis, while coarse chromatin pattern was significant only in a univariate analysis. The combination of absence of pleomorphism, rare single cells, tight cluster arrangement, fine chromatin pattern, and absence of macronucleoli was seen only in benign cases. Assessment of background material was helpful in the differential diagnosis and classification. Necrosis was only found in high-grade cases.

Cytohistologic correlations in 56 synovial sarcomas in 36 patients: the Institut Curie experience

Synovial sarcoma (SS) is a high-grade malignant soft tissue tumor that manifests different phenotypic subtypes that may render their cytologic evaluation challenging. Although several cytologic studies of SS have been published, correlative studies of cytologic and corresponding histologic features are limited. To better define the cytological features of various SS forms, we reviewed the cytologic and the corresponding histologic material of 56 tumors from 36 patients. Classical patterns were defined as dispersed or small clusters of cells with bland chromatin, inconspicuous nucleoli, oval to spindle-shaped cytoplasm and branching tumor tissue fragments, vessel stalks, acinar structures in scant mucin background, seen in all 53 (94.7%) cellular cases. Epithelial, squamous, round cells, mast cells, necrosis, comma-like nuclei, marked nuclear atypia, secretory mucin, and rosette-like structures were also occasionally observed. Comparing the histological subtype we noted that epithelial cells and secretory mucin were restricted to biphasic SS, round cells to poorly differentiated SS, and comma-like nuclei to monophasic fibrous SS. We conclude that the classical pattern is highly suggestive of SS of all three monophasic, biphasic, or poorly differentiated subtypes. These characteristics, along with molecular genetic studies, may improve the cytologic diagnosis of SS.