Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA): experience of an academic centre in the USA.

OBJECTIVES: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has become widely accepted as an effective modality for obtaining tissue for primary diagnosis and staging. We have been using EUS-FNA since July 2001 and herein we summarize our experience over a 5-year period. METHODS: A computer-based search for in-house EUS-FNA was performed in the pathology database from July 2001 to October 2006. To calculate the sensitivity, specificity and accuracy of EUS-FNA, the cytology diagnosis was compared with the surgical follow-up. RESULTS: A total of 951 EUS-FNAs were performed during the study period and included 279 pancreatic solid lesions, 186 pancreatic cyst lesions, 249 lymph node aspirations, 111 gastrointestinal (GI) tract submucosal lesions, and 126 miscellaneous lesions. EUS-FNA had a very high sensitivity and accuracy for solid pancreatic lesions (94.7 and 97.7%, respectively), low sensitivity and accuracy but high specificity (47, 64.8 and 95%, respectively) for cystic lesions. Cyst fluid carcinoembryonic (CEA) levels were significantly higher in mucinous neoplasms than non-neoplastic cysts. EUS-FNA also had very high sensitivity and specificity for detecting metastatic carcinoma in lymph nodes (95 and 100%, respectively). GI submucosal spindle cell tumours were further classified with immunohistochemical stains performed either on a cell block or a core biopsy obtained via EUS guidance. CONCLUSIONS: EUS-FNA has a very high sensitivity and accuracy for pancreatic solid lesions, but the sensitivity for cystic lesions is generally low. Cyst fluid chemical analysis for CEA is helpful, but the overlap between mucinous neoplasm and non-neoplastic cysts is significant. Recognizing GI contamination is important and immunohistochemical stains are useful for GI submucosal spindle cell lesions.

Hyaline globules in renal cell carcinoma and hepatocellular carcinoma. A clue or a diagnostic pitfall on fine-needle aspiration?

The cytologic similarity to hepatocellular carcinoma (HCC) of 2 cases of granular renal cell carcinoma (RCC) with hyaline globules (HGs) prompted us to evaluate the frequency of HGs in RCC and HCC and the association between cell type, differentiation, and malignant potential of these 2 neoplasms and the presence of HGs. We studied fine-needle aspirates from 23 cases of RCC (primary, 7; metastatic, 16) and 23 cases of primary HCC and noted anatomic site, tumor cell type, and presence, quality, and quantity of HGs. Fuhrman nuclear grade was assigned to RCC and overall differentiation to HCC cases. RCC cell type was granular (7), mixed (4), and clear (12). HCC cases were granular (22) and clear (1). Morphologically similar, predominantly intracytoplasmic HGs were identified in 4 RCCs and 10 HCCs. All 4 RCCs with HGs were at metastatic sites, granular cell type, and high Fuhrman grade. HGs showed no association with differentiation of HCC. While HGs are seen more commonly in HCC than in RCC, their presence in an adenocarcinoma should bring renal origin into consideration. The presence of HGs in metastatic granular RCC, particularly in the liver, can lead to misinterpretation as primary HCC.

Occurrence of intercellular spaces (windows) in metastatic adenocarcinoma in serous fluids: a cytomorphologic, histochemical, and ultrastructural study.

The application of cytomorphologic criteria to the examination of serous effusions allows the reliable diagnosis of malignancy in the majority of cases. One feature observed in tissue fragments previously thought to be indicative of mesothelial origin is the presence of intercellular windows, presumably due to long surface microvilli. In this study, however, we examined cytologic preparations of 143 effusion and body-cavity washing specimens and noted distinct intercellular window formation within tissue fragments of adenocarcinoma in 13% of the cases studied. Stains for mucicarmine, Alcian blue with hyaluronidase pretreatment, and periodic acid-Schiff following diastase digestion on corresponding cell block material demonstrated that intercellular mucin contributes to such window formation in greater than half of these cases. Thus the presence of intercellular windows within tissue fragments does not, in isolation, preclude the diagnosis of malignancy in serous effusions.

PAPNET computer-aided rescreening for detection of benign and malignant glandular elements in cervicovaginal smears: a review of 61 cases.

An increasing proportion of the recent cytodiagnostic literature has focused on automation of the Pap smear screening process in hopes of finding a feasible system to aid in the reduction of the number of reported false-negative cases. In a sense, these systems can be thought of as computer-driven sensitivity enhancers for better detection of abnormalities in smeared cervicovaginal specimens. The PAPNET system (Neuromedical Systems, Inc., Suffern, NY) relies on a neural network of artificial-intelligence technology to recognize the complex cellular arrays present in Pap smears, and was originally intended to aid in the identification of morphologically abnormal cells of squamous origin. Herein, we present the results of 61 smears containing a mixture of known diagnostically important benign, dysplastic, and malignant glandular cellular abnormalities which were reviewed by the PAPNET technology. The PAPNET system detected the diagnostic glandular material in 44 of the 45 benign cases reviewed (98% detection rate). In addition, the PAPNET technology identified abnormal cellular material in 15 of the 16 studied smears from patients with malignant/dysplastic morphology (94% detection rate). These data indicate that the PAPNET neural networks are capable of detecting cells with aberrant glandular cytomorphology. In both cases missed by the PAPNET system, the number of abnormal cells per slide was very low, indicating that as with human screeners, the capabilities of this semiautomated method may be exceeded when an extreme paucity of diagnostic cellular material is present in a given slide. Further and larger reviews of glandular abnormalities by automated technologies are needed to assess these systems for their true efficacy at diminishing false-negative cases.