Lymph node fine needle cytology in the staging and follow-up of cutaneous lymphomas.

BACKGROUND: Lymph nodal involvement is an important clinical-pathological sign in primary cutaneous lymphoma (PCL), as it marks the transformation/evolution of the disease from localized to systemic; therefore the surveillance of lymph nodes is important in the staging and follow up of PCL. Fine needle cytology (FNC) is widely used in the diagnosis of lymphadenopathies but has rarely been reported in PCL staging and follow-up. In this study an experience on reactive and neoplastic lymphadenopathies arisen in PCL and investigated by FNC, combined to ancillary techniques, is reported. METHODS: Twenty-one lymph node FNC from as many PCL patients were retrieved; 17 patients had mycosis fungoides (MF) and 4 a primary cutaneous B-cell lymphoma (PBL). In all cases, rapid on site evaluation (ROSE) was performed and additional passes were used to perform flow cytometry (FC), immunocytochemistry (ICC) and/or polymerase chain reaction (PCR) to assess or rule out a possible clonality of the corresponding cell populations. RESULTS: FNC combined with FC, ICC, and PCR identified 12 cases of reactive, non specific, hyperplasia (BRH), 4 dermatopathic lymphadenopathy (DL), 4 lymph nodal involvement by MF and 1 lymph nodal involvement by cutaneous B-cell lymphoma. CONCLUSIONS: FNC coupled with ancillary techniques is an effective tool to evaluate lymph node status in PCL patients, provided that ROSE and a rational usage of ancillary techniques is performed according to the clinical context and the available material. The method can be reasonably used as first line procedure in PCL staging and follow up, avoiding expensive and often ill tolerated biopsies when not strictly needed.

Fine-needle cytology and flow cytometry assessment of reactive and lymphoproliferative processes of the breast.

OBJECTIVE: The breast may be affected by reactive and lymphoproliferative processes such as primary (PBL) or secondary (SBL) lymphoma, reactive intramammary lymph nodes and sclerosing lobulitis; imaging may be not specific and surgical treatment not indicated. We report an experience with fine-needle cytology (FNAC) combined with flow cytometry (FC) and immunocytochemistry (ICC) in the diagnosis of these processes. STUDY DESIGN: Thirty-seven cases comprising intramammary lymph nodes (n = 15), sclerosing lobulitis (n = 2), PBL (n = 11) and SBL (n = 9) are reported. FNAC was used to prepare traditional smears, conventional ICC or FC. Cytological diagnoses were compared to the imaging data, checked by histology or follow-up and statistically evaluated. RESULTS: Imaging was not conclusive in most PBL, SBL, sclerosing lobulitis and some intramammary lymph nodes. FNAC combined with FC and ICC provided a definitive diagnosis of intramammary lymph node, sclerosing lobulitis, PBL and SBL in 18 cases with indication of the specific subtype in 10 cases. Statistical analysis showed 90% sensitivity, 100% specificity, 100% positive predictive value and 89% negative predictive value. CONCLUSIONS: FNAC combined with FC and ICC is a helpful procedure for the diagnosis of reactive and lymphoproliferative processes of the breast. It may prevent unnecessary biopsy and speed up therapeutic procedures.

Cutaneous needle track seeding of mesothelioma diagnosed by fine needle aspiration cytology: a case report.

BACKGROUND: Diagnostic and therapeutic procedures for mesothelioma require surgical biopsy or the usage of different-sized needles. Thoracic wall involvement along the surgical or needle tracks has been reported. CASE: A 57-year-old woman who had suffered from non-Hodgkin's lymphoma complained of dyspnea and left pleural effusion. The patient had been treated with chemotherapy and radiotherapy and was in remission since then. Thoracentesis was performed using a 22-gauge needle; the cytologic diagnosis was malignant pleural mesothelioma. Within 2 weeks from thoracentesis, the patient complained of an erythematous swelling in her left chest wall, in the area of the needle track. Fine needle aspiration cytology (FNAC) of the swelling was performed using a 23-gauge needle; 2 smears and a cell block were prepared. Smears showed neoplastic cells in sheets and papillary configuration with the features of mesothelial lineage. Immunocytochemistry showed positivity for calretinin and vimentin. Cytologic slides of the former effusion showed an overlapping of the cytologic and immunocytochemical features. A diagnosis of chest wall involvement from mesothelioma was established and histologically confirmed. CONCLUSION: Chest wall infiltration is a definite risk in the management of pleural mesothelioma, and FNAC is a useful procedure for a timely diagnosis of this ominous complication.

Fine needle aspiration cytology of a cutaneous metastasis from an extraadrenal paraganglioma: a case report.

BACKGROUND: Pheochromocytomas/paragangliomas are rare tumors originating from neuroectodermic cells, which metastasize in only 10% of cases. CASE: A case of cutaneous metastasis of an extramedullary paraganglioma was diagnosed by fine needle aspiration cytology (FNAC). A 39-year-old woman complained of a recently arisen subcutaneous nodule located on the scalp. Two years before she had suffered from a sporadic extraadrenal paraganglioma located on the sacrum, and it had been evaluated by FNAC. Smears were highly cellular and monomorphous; the cells were uniform and mainly isolated with round or ovoid nuclei, dense chromatin and inconspicuous nucleoli, if any. The cytoplasm was ill defined, clear or granular. Oval-spindle-shaped cells and occasional cells with larger nuclei were also observed. Abundant fibrillar material was present in the background, intermingled with the surrounding cells. The immunocytochemical staining performed on cell block sections showed negativity for CK20, HMB45 and LCA and positivity for chromogranin and S100. The cytologic diagnosis was a neuroendocrine tumor, consistent with a metastasis from the former sacral paraganglioma. CONCLUSION: On conventional samples the cytologic features of paraganglioma are typical enough to allow a cytologic diagnosis of a neuroendocrine tumor; this neoplasm should be considered in the differential diagnosis, even in such unusual locations, because of its unpredictable biologic behavior.

Fine needle cytology and flow cytometry of ectopic cervical thymoma: a case report.

BACKGROUND: A case of ectopic cervical thymoma (ECT) in which fine needle cytology (FNC) and flow cytometry (FC) have orientated the cytologic diagnosis, is described. CASE: A 57-year-old woman underwent FNC of a right latero-cervical nodule. The smear showed a dispersed lymphoid-cell population; therefore, a second FNC was used for FC and to prepare a cell block. Smears were highly cellular. Cells were medium or large sized, with scanty cytoplasm and nuclei with dispersed chromatin; large cells showed evident nucleoli. Immunohistochemistry on additional smears were positive for CD45RO and Ki67 in most of the cells, and negative for CK pan, CD20, thyreoglobulin and calcitonin. FC showed the following phenotype: CD2/CD3/CD7 = 67%, CD10 = 61%, CD4/CD8 = 62%. CD19 and light chains were not expressed. A diagnosis of T-cell lymphoid proliferation was made and ECT was suggested; histological diagnosis was cervical ectopic benign type B1 thymoma. CONCLUSION: FC may support the FNC diagnosis of ECT because of the specific phenotype of lymphoid cells showing the profile of "polyclonal" (CD2/CD3/CD7+) and thymic T-cells (CD10+, CD4/CD6+). FNC and FC may suggest the diagnosis of ECT even in the absence of detectable epithelial cells.

Pulmonary langerhans cell histiocytosis (histiocytosis X) on bronchoalveolar lavage: a report of 2 cases.

BACKGROUND: Pulmonary Langerhans cell histiocytosis (PLCH) is an interstitial lung disease characterized by bilateral nodular and cystic lesions. Clinically it seems to be a reactive process related to cigarette smoking. CASES: In 2 cases of PLCH, cytologic and immunocytochemical evaluation of bronchoalveolar lavage (BAL) fluid was successfully used for the diagnosis of PLCH. Two heavy smokers complained of fever, cough and debilitation. Serologic and hematologic values were normal. In both cases radiography and computed tomography (CT) were similar, showing multiple bilateral nodular or cystic lesions in the middle and upper lung zones. Cytospins obtained from BAL were Papanicolaou and May-Grünwald-Giemsa stained; others were immunostained with cytokeratin cocktail, CD1a and S-100. Cytospins showed a monomorphous and dispersed cell population consisting ofmononucleated or binucleated and occasionally multinucleated histiocytes. Single cells showed wide, well-defined, acidophilic cytoplasm and oval or kidney-shaped, vesicular nuclei with irregular shapes, evident nucleoli and frequent grooves and indentations. Immunocytochemical staining showed diffuse cytoplasmic positivity for S-100 and CD1a and negativity for cytokeratin; only the few cylindrical cells present in the cytospins were positive for cytokeratin. In both cases the cytologic diagnosis of PLCH was confirmed by subsequent CT and clinical follow-up. CONCLUSION: Cytologic and immunocytochemical evaluation of BAL fluid permits a definitive diagnosis of PLCH. This cytologic diagnosis is clinically relevant because it permits surgical biopsy to be bypassed and allows waiting for a possible spontaneous or pharmacologic resolution.

CD10, BCL6, and MUM1 expression in diffuse large B-cell lymphoma on FNA samples.

BACKGROUND: Gene expression profiling has divided diffuse large B-cell lymphoma (DLBCL) into 2 main subgroups: germinal center B (GCB) and non-GCB type. This classification is reproducible by immunohistochemistry using specific antibodies such as CD10, B-cell lymphoma 6 (BCL6), and multiple myeloma oncogene 1 (MUM1). Fine-needle aspiration (FNA) plays an important role in the diagnosis of non-Hodgkin lymphoma, and in some cases FNA may be the only available pathological specimen. The objectives of the current study were to evaluate CD10, BCL6, and MUM1 immunostaining on FNA samples by testing the CD10, BCL6, and MUM1 algorithm on both FNA cell blocks (CB) and conventional smears (CS), evaluating differences in CB and CS immunocytochemical (ICC) performance, and comparing results with histological data. METHODS: Thirty-eight consecutive DLBCL cases diagnosed by FNA were studied. Additional passes were used to prepare CB in 22 cases and CS in 16 cases; the corresponding sections and smears were immunostained using CD10, BCL6, and MUM1 in all cases. The data obtained were compared with histological immunostaining in 24 cases. RESULTS: ICC was successful in 33 cases (18 CB and 15 CS) and not evaluable in 5 cases (4 CB and 1 CS). The CD10-BCL6-MUM1 algorithm subclassified DLBCL as GCB (9 cases) and non-GCB (24 cases). ICC data were confirmed on histologic staining in 24 cases. CONCLUSIONS: CD10, BCL6, and MUM1 ICC staining can be performed on FNA samples. The results herein prove it is reliable both on CB and CS, and is equally effective and comparable to immunohistochemistry data.

Metaplastic breast carcinoma on fine-needle cytology samples: a report of three cases.

Metaplastic breast carcinoma (MBC) may have a varied presentation on fine-needle cytology samples. We herewith describe three cases of MBC found in our series. One of these cases showed a peculiar mixture of malignant ductal, apocrine type, and squamous epithelial cells with fascicles of spindle cells with variable degree of atypia and was diagnosed as metaplastic carcinoma of the carcino-sarcomatous type. The other two lesions were characterized by an abundant chondroid extracellular matrix to which were variably admixed carcinomatous and chondroid-type cells, with variable degree of atypia. Both these latter cases were defined as matrix-producing metaplastic carcinomas. Because of the various presentation of MBC on fine-needle cytology samples and the possible influence of needle "sampling" on the cytological specimen, the spectrum of differential diagnoses to be considered may encompass a number of benign and malignant entities, like keratinous subareolar cysts, malignant fibroepithelial lesions with myxo-chondroid stroma, and true sarcomas of the breast, with cartilaginous metaplasia. It is the Authors' feeling that, with optimal samples, the cytomorphological findings of this rare variant of breast carcinoma permit its accurate pre-operative diagnosis.

Fine needle cytology of endometriosis: experience with 10 cases.

OBJECTIVE: To evaluate whether commonly used cytologic criteria for the diagnosis of endometriosis are sufficiently specific, to assess the possible role of special methods in the differential diagnosis and to assess the clinical meaning and drawbacks of a cytopathologic diagnosis of endometriosis by fine needle aspiration. STUDY DESIGN: We retrieved 10 cases of endometriosis from our files that had been diagnosed primarily by fine needle cytology (FNC) with subsequent tissue study. In some cases additional cytospin preparations and/or smears had been used for cytochemistry (periodic acid-Schiff stain, mucicarmine) or immunocytochemistry (pan-cytokeratin, cytokeratin 7, vimentin, CD10) using a 3-step streptavidin-biotin-immunoperoxidase reaction. RESULTS: The cell pattern and immunocytochemical profile of the cases suggested a diagnosis of endometriosis. All cases were histologically confirmed. CONCLUSION: With optimal preparations a confident cytologic diagnosis of endometriosis may be made with ease, permitting correct treatment of the disease and, in selected cases, planning of preoperative pharmacologic therapy.

Benign chondroblastoma on fine-needle aspiration smears: A seven-case experience and review of the literature.

We report seven cases of chondroblastoma (CB) of bone, diagnosed by Fine-Needle Aspiration Cytology (FNAC), and confirmed by histomorphological examination. The concurrence of some cytomorphologic findings - mononucleated cells, multinucleated cells, and intercellular chondroid substance - unequivocally suggested the cytological diagnosis of CB. We also reviewed the literature on this topic in order to discuss morphological criteria and the importance of needle size. The differential diagnosis between CB, Giant Cell Tumor of Bone, and Eosinophilic Granuloma is further discussed.

Multidisciplinary diagnostic approach combining fine needle aspiration, core needle biopsy and imaging features of a presacral myelolipoma in a patient with concurrent breast cancer.

Myelolipomas are uncommon benign tumors composed of mature adipose tissue mixed with hematopoietic elements; these tumors can occur in both the adrenal glands and extra-adrenal locations, the presacral region being the most frequent extra-adrenal site. We present a case of presacral myelolipoma diagnosed by fine needle aspiration (FNA) and core needle biopsy (CNB) in a 55-year-old woman with concurrent invasive ductal breast cancer. TC and RM imaging were consistent with the diagnosis of presacral myelolipoma. The lesion was discovered incidentally during the staging procedure for breast malignancy. The purpose of our work is to describe the FNA and CNB finding in combination with the imaging features of this uncommon lesion.

Expression of NK-associated antigens in extramedullary lymph nodal blast crisis of chronic myeloid leukemia on fine-needle cytology.

A case is reported of a 62-yr-old male suffering from chronic myelogenous leukemia (CML) who developed an extramedullary, para-orthic lymph-nodal blast crisis without blood or bone marrow involvement and expression of CD56/NK associated marker. The diagnosis was performed on ultrasound-guided fine-needle cytology by an immunocytochemical and flow cytometric analysis. Conventional smears showed a monomorphous population of disperse, undifferentiated cells without cytoplasm. Cells showed fragile nuclei, vesicular chromatin, and evident nucleoli. Immunocytochemistry performed on cytospin slides were negative for cytokeratin, LCA, CD20, CD45Ro, and myeloperoxidase (MPO). Flow cytometry analysis proved the myeloid origin of the tumor by expression of CD13, CD34, and CD38 and showed aberrant expression of CD56. Cytological diagnosis was confirmed by histological examination. CD56 expression is generally an expression of NK lymphoid proliferation and may be observed in acute myelogenous leukemia but has rarely been reported in CML and its related blast crisis. This unusual expression, its possible explanation, the related technical problems, and clinicopathological aspects are discussed.

Aggressive papillary male breast carcinoma on fine-needle cytology sample.

Papillary carcinoma (PC) is a histological variant of breast carcinoma that is more frequently observed in males than in females, showing the same cytological features in both sexes. PC is characterized by a low grade of malignancy and a generally favorable course. We describe a case of male breast PC (MPC) diagnosed by fine-needle cytology (FNC) in which some aggressive morphologically detectable features were associated with bland cytologic features of the tumor. FNC was performed on a 3 cm palpable mass of the left breast of a 55-yr-old male. FNC yielded abundant bloody material. Two smears were Diff-Quik and Papanicolaou stained, others were used for immunocytochemical assessment of estrogen, progesterone, c-erbB-2, and Ki-67; another was Feulgen stained for DNA ploidy. Smears were highly cellular, showing isolated cells and papillary structures. Cells showed tall and well-defined cytoplasm with a columnar aspect, light anisonucleosis, coarse chromatin, and small nucleoli. Immunoperoxidase staining demonstrated positivity for estrogen (50%), negativity for progesterone, intense positivity for c-erbB-2, with specific membrane staining and positivity for Ki-67 in more than 20% of the cells. DNA-ploidy showed an aneuploid histogram with 5c exceeding rate (5cER) of 59% and 2c deviation index (2cDI) of 29%. Subsequent surgical pathology examination confirmed the cytological diagnosis of papillary carcinoma; moreover, it revealed neoplastic endolymphatic thrombi and infiltrative border of the tumor that reached the thoracic wall. Cytological features can suggest diagnosis of MPC on FNC samples. Immunocytochemical evaluation of c-erbB-2 and Ki-67 and DNA ploidy evaluation on cytological smears might reveal a biological aggressiveness of PC despite the bland microscopic features of the tumor and this should influence the therapeutic procedure.

p27(Kip1) expression and grading of breast cancer diagnosed on cytological samples.

The progressive reduction in p27(Kip1) (p27) protein immunohistochemical staining with increasing histological grading is a well-established finding occurring in breast cancer, and its role as diagnostic complement and prognostic marker has been thoroughly evaluated. To clarify whether this test may be applied to breast cytopathology, we performed p27 immunostaining on fresh fine-needle cytology (FNC) samples from 10 benign and 40 malignant breast lesions. On average, p27 immunostaining was significantly lower in carcinomas than in benign lesions (P < 0.005). In particular, among carcinomas, p27 immunostaining progressively reduced from well-to poorly differentiated lesions (G1 vs. G2, P < 0.05; G1 vs. G3, P < 0.001; G2 vs. G3; P < 0.001). A similar trend was noted in a subgroup of 20 matched FNCs and histological samples of breast carcinomas, when p27 immunostaining on FNCs was stratified according to the histological grading (G1 vs. G2, P = 0.18; G1 vs. G3, P < 0.05; G2 vs. G3, P < 0.05). In addition, p27 immunostaining on FNCs showed a good positive correlation with that on histology (Spearman R = 0.58; P < 0.01), with a diagnostic concordance between samples of 85%, by using the standard 50% positive cell cutoff. Taken in concert, our data suggest that p27 immunostaining is a reliable marker of tumor cell differentiation in breast cytopathology as well as in histopathology. Accordingly, staining FNCs for p27 may be an useful complement in addition to cytological grading in the preoperative assessment of breast cancer.

Fine needle aspiration biopsy of hepatic focal fatty change. A report of two cases.

BACKGROUND: In rare instances, hepatic steatosis produces a circumscribed, nodular lesion described as focal fatty liver change (FFLC). The ultrasonographic and computed tomographic patterns are those of an isointense or hyperechoic nodule, sometimes simultating metastasis. CASES: Fine needle aspiration biopsy was performed under ultrasonographic control in two men aged 65 and 67 years who had previously undergone emicolectomy and gastrectomy for adenocarcinoma. Routine hepatic ultrasound showed solitary nodules, of 3 and 4 cm in diameter. The microscopic patterns were similar and highly cellular in both cases. Cells were isolated or organized in sheets and characterized by large, intracytoplasmic, clear vacuoles that displaced nuclei to the periphery of the cells, flattening them against the cytoplasmic membrane and giving these cells a signet-ring appearance. Nuclei were generally round and nucleolated or dense and hyperchromatic when flattened onto the cytoplasmic membrane. Normal hepatocytes were interspersed in the background, and in some areas of the slides hepatocytes with one or more small intracytoplasmic vacuoles with cytologic features intermediate between those of vacuolated cells and normal hepatocytes were present. Digested periodic acid-Schiff staining, performed on destained, fixed smears, gave negative results. The cytologic diagnosis was FFLC. Clinical and echographic follow-up confirmed the cytologic diagnosis. CONCLUSION: The ultrasonographic and microscopic features of FFLC may mimic those of metastasis. A proper cytologic diagnosis may contribute to the diagnostic workup of these rare lesions.

Occult lymph node metastasis from desmoplastic small round cell tumor diagnosed by fine needle aspiration cytology. A case report.

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a rare but well-defined neoplasm generally forming in the abdominal or pelvic cavity of young males and has distinct clinical, immunohistochemical and molecular features. Cytologic features of DSRCT have been described on fine needle aspiration of primary tumors. An occult lymph node metastasis of DSRCT diagnosed through the cytologic features, a basic immunocytochemical panel and DNA ploidy evaluation on cytospins obtained by fine needle aspiration is reported. CASE: Aspiration cytology was performed on an inguinal lymph node from a 20-year-old male. A Diff-Quik-stained smear showed mature lymphocytes and groups of undifferentiated, small cells with scanty cytoplasm, dense and coarse chromatin, and small nucleoli. Basic immunocytochemical stains showed negativity for leukocyte-common antigen and neuron-specific enolase and positivity for cytokeratin cocktail (Cam 5.2), vimentin and desmin, the last with characteristic paranuclear dotlike positivity. DNA ploidy evaluation showed an aneuploid histogram with a low 5c exceeding rate. CONCLUSION: Cytologic and immunocytochemical features suggest the diagnosis of DSRCT on fine needle aspiration cytology samples even in cases of a metastatic, unknown primary tumor. Because of the tumor's aggressiveness, a rapid and accurate diagnosis is required.

Hemophagocytic histiocytosis diagnosed by fine needle aspiration cytology of the spleen. A case report.

BACKGROUND: Hemophagocytic histiocytosis (HPS) is an idiopathic, familial or secondary syndrome characterized by mature histiocytes causing intensive erythrophagocytosis. CASE: A 2-month-old male suffering from autoimmune hemolytic anemia, fever, jaundice and hepatosplenomegalia underwent fine needle aspiration cytology of the spleen. Aspiration was performed using a 23-gauge, short needle with a subcostal approach. The smear showed a monomorphous cell population of mature histiocytes with marginal nuclei and wide, well-defined cytoplasm. The cytoplasm was microvaculated and often contained > or = 1 erythrocytes and occasional lymphocytes. Immunostaining performed on cytospin samples showed diffuse positivity for alpha-1-antichymotrypsin and S-100. Differential diagnosis with malignant histiocytosis, Langerhans histiocytosis and sinus histiocytosis with massive lymphadenopathy was established. HPS was diagnosed because of the cytologic and immunocytochemical features and clinical data. CONCLUSION: HPS may be diagnosed using fine needle aspiration of the spleen when other biopsy samples have been unsuccessful. Cytologic, diagnosis of HPS should always be considered in a specific clinical setting, because early treatment can often save the patient's life.

Lymph node and lymphoid organs fine needle aspiration cytology: historical background.

Lymph node has probably been the first target of Fine Needle Cytology (FNC) and among the latest to be accepted as an affordable diagnostic procedure. In 1912, dr. Hirschfeld performed FNC to diagnose cutaneous lymphomas and other tumours. Subsequently FNC was used to diagnose lymphoblastoma and splenic FNC to diagnose leishmaniasis on Romanowsky-stained smears. One of the first systematic study on lymph node FNC was then performed at John Hopkins Hospital, in Baltimore (USA) using FNC and Romanowsky stain on air-dried smears. In the twenties, two independent groups from Memorial Hospital (New York, USA), worked on FNC of a large scale of different human pathologies. One of this study reported 1,405 diagnoses of cancer and other diseases by means of FNC, mainly performed on lymph nodes (662 cases). In the sixties, at the Karolinska Hospital (Stockholm, Sweden) a group of cytopathologists started a Cytopathology Service available to the whole Institution, which exploited all fields of FNC. Since then, the procedure spread all over the word and nowadays it is routinely used for the diagnosis of different organs and pathologies including lymph node. Distinguished cytopathologists have worked on lymph nodal FNC producing significant advances and highlighting advantages and inevitable limitations of the technique. Despite some persistent criticism, FNC is a generally accepted procedure in the first diagnosis of lymph nodes enlargement. Moreover, numerous studies have demonstrated that vital cells obtained by FNC are excellent samples suitable for molecular evaluation, offering new challenging application to lymph node FNC.

Impact of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in lymph nodal and mediastinal lesions: a multicenter experience.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is an established procedure in lung cancer (LC) staging and in the diagnosis of mediastinal masses. Most of the experiences reported refer to single specialized centers where dedicated teams of endoscopists and pathologists perform the procedure. We report the EUS-FNA experience of a cooperation group involving clinicians and cytopathologists from three hospitals. Fifty-seven consecutive EUS-FNA of mediastinal nodes in LC patients, eight mediastinal and two subdiaphragmatic masses were collected in 3 years. EUS-FNA was performed by two endoscopists and three experienced pathologists. On-site evaluation was performed in all cases by the three cytopathologists. Lymph node negative cases underwent surgery, which confirmed the cytological diagnoses but also detected two false negatives. Four of the 10 EUS cytological diagnoses of mediastinal and subdiaphragmatic masses were histologically confirmed. All EUS diagnoses were blindly reviewed by three pathologists to assess intra and interpersonal reproducibility. FNA-EUS diagnoses were: 10 inadequate (17%), 10 negative (17%), 4 suspicious (7%) and 33 positive (59%). Diagnoses of mediastinal and subdiaphragmatic masses were: relapse of lung carcinoma (3), mesenchimal tumor not otherwise specifiable (3), gastrointestinal stromal tumor (GIST) (1), esophageal carcinoma (2) and paraganglioma (1). The sensitivity attained was 85% and the specificity 100%; revision of the slides demonstrated a significant diagnostic reproducibility of the three cytopathologists (P < 0.5). The sensitivity and specificity attained were similar to those reported in the literature suggesting that experienced cytopathologists and endoscopists from different institutions can employ the same procedure reaching comparable results.