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Biomedical subjects

J F Southern

Publications and source records attributed to J F Southern.

At least 37 records · Page 2Linked to original sources
PubMed1997

Transcranial Doppler ultrasound criteria for hemodynamically significant internal carotid artery stenosis based on residual lumen diameter calculated from en bloc endarterectomy specimens.

BACKGROUND AND PURPOSE: Transcranial Doppler (TCD) is often used in conjunction with carotid duplex ultrasonography (CDUS) to evaluate the hemodynamic significance of internal carotid artery (ICA) stenosis. We examined the sensitivity and specificity of TCD criteria for detection of a hemodynamically significant stenosis (residual lumen diameter < 1.5 mm) at the origin of the ICA. METHODS: We selected patients who underwent carotid end-arterectomy (CEA) and had preoperative TCD data available. Eighty-one patients underwent transorbital evaluation, 49 of whom also had transtemporal TCD performed. The endarterectomy specimens were removed en bloc and sectioned, and the minimal residual lumen diameter calculated by computer analysis. RESULTS: For the transorbital approach, the strongest indicators of a residual lumen diameter < 1.5 mm were reversed flow in the ipsilateral ophthalmic artery and a > 50% peak systolic velocity difference between the carotid siphons (distal ICAs) in patients with unilateral ICA origin stenosis. They were 100% specific and 31% and 26% sensitive, respectively. For the transtemporal approach in patients with a unilateral stenosis, a > 35% difference in ipsilateral middle cerebral artery (MCA) peak systolic velocity relative to the contralateral MCA or a > 50% difference in contralateral anterior cerebral artery (ACA) peak systolic velocity relative to the ipsilateral ACA were 100% specific for identifying a residual lumen diameter of < 1.5 mm. Sensitivities were 32% and 43%, respectively. Irrespective of contralateral stenosis, a > 35% difference in ipsilateral MCA peak systolic velocity relative to the ipsilateral posterior cerebral artery had a 100% specificity and a 23% sensitivity for detecting a < 1.5 mm minimal residual lumen diameter. CONCLUSIONS: Although the TCD sensitivity for detecting a hemodynamically significant stenosis is relatively low, it can be highly specific (up to 100%). We conclude that TCD enhances the specificity of highly sensitive CDUS criteria for detecting a hemodynamically significant ICA stenosis.

Aged↗
PubMed1997

Optical biopsy in human urologic tissue using optical coherence tomography.

Optical Coherence Tomography (OCT) is a recently developed non-invasive technique for obtaining high resolution, cross-sectional images of human tissue. This work investigated the capability of OCT to differentiate the architectural morphology of urologic tissue with the long term aim of using OCT as an adjunct to endoscopic imaging and to improve the efficiency of interventional procedures such as transurethral prostatectomy (TURP). Urologic tissues were taken postmortem, dissected, and imaged using OCT. Microstructure was delineated in different urologic tissues, including the prostatic urethra, prostate, bladder, and ureter, with an axial resolution of 16 +/- 1 microm., higher than any clinically available endoscopic intraluminal imaging technology. The ability of OCT to provide non-contact high resolution imaging of urologic tissue architectural morphology (i.e. optical biopsy), without the need for excisional biopsy, suggests the potential of using OCT to obtain information on tissue microstructure that could only previously be obtained with conventional biopsy.

Biopsy↗
PubMed1997

Optical biopsy in human gastrointestinal tissue using optical coherence tomography.

OBJECTIVES: Optical coherence tomography (OCT) is a new technique for performing high-resolution, cross-sectional tomographic imaging in human tissue. OCT is somewhat analogous to ultrasound B mode imaging except that it uses light rather than acoustical waves. OCT has over 10 times the resolution of currently available clinical high-resolution imaging technologies. In this work, we investigate the capability of OCT to differentiate the architectural morphology of gastrointestinal tissue with the long-term objective of extending OCT to endoscopic based diagnostics. METHODS: Normal and diseased gastrointestinal tissues were taken postmortem and imaged using OCT. Images were compared with corresponding histology to confirm tissue identity and suggest the mechanisms that produce tissue contrast. RESULTS: Microstructure was delineated in different tissues, including the esophagus and colon, at 16 +/- 1 microns resolution, higher than any clinically available cross-sectional imaging technology. Differentiation of tissue layers, such as the mucosa, submucosa, and muscularis were achieved because of their different optical properties. CONCLUSIONS: The ability of OCT to provide high-resolution in situ imaging of gastrointestinal microstructure, without the need for excisional biopsy, suggests the feasibility of using OCT as a powerful diagnostic imaging technology, which can be integrated with conventional endoscopy.

Biopsy↗
PubMed1996

Magnetic resonance images lipid, fibrous, calcified, hemorrhagic, and thrombotic components of human atherosclerosis in vivo.

BACKGROUND: Although MRI can discriminate the lipid core from the collagenous cap of atherosclerotic lesions in vitro with T2 contrast, it has not yet produced detailed in vivo images of these human plaque components. METHODS AND RESULTS: We imaged seven lesions from six patients who required surgical carotid endarterectomy and calculated T2 in vivo before surgery in various plaque regions. Using the same acquisition parameters, we repeated these measurements in vitro on the resected fragment and compared MR images with histology. T2 values calculated in vivo correlate with in vitro measurements for each plaque component; the in vitro discrimination we demonstrated previously with T2 contrast can therefore be performed similarly in vivo. CONCLUSIONS: MRI is the first noninvasive imaging technique that allows the discrimination of lipid cores, fibrous caps, calcifications, normal media, and adventitia in human atheromatous plaques in vivo. This technique also characterizes intraplaque hemorrhage and acute thrombosis. This result may support further investigations that include MRI of plaque progression, stabilization, and rupture in human atherosclerosis.

Aged↗
PubMed1996

Optical coherence tomography for optical biopsy. Properties and demonstration of vascular pathology.

BACKGROUND: Optical coherence tomography (OCT) is an recently developed medical diagnostic technology that uses back-reflected infrared light to perform in situ micron scale tomographic imaging. In this work, we investigate the ability of OCT to perform micron scale tomographic imaging of the internal microstructure of in vitro atherosclerotic plaques. METHODS AND RESULTS: Aorta and relevant nonvascular tissue were obtained at autopsy. Two-dimensional cross-sectional imaging of the exposed surface of the arterial segments was performed in vitro with OCT. A 1300-nm wavelength, superluminescent diode light source was used that allows an axial spatial resolution of 20 microns. The signal-to-noise ratio was 109 dB. Images were displayed in gray scale or false color, Imaging was performed over 1.5 mm into heavily calcified tissue, and a high contrast was noted between lipid- and water-based constituents, making OCT attractive for intracoronary imaging. The 20-microns axial resolution of OCT allowed small structural details such as the width of intimal caps and the presence of fissures to be determined. The extent of lipid collections, which had a low backscattering intensity, also were well documented. CONCLUSIONS: OCT represents a promising new technology for imaging vascular microstructure with a level of resolution not previously achieved with the use of other imaging modalities. It does not required direct contact with the vessel wall and can be performed with a catheter integrated with a relatively inexpensive optical fiber. The high contrast among tissue constituents, high resolution, and ability to penetrate heavily calcified tissue make OCT an attractive new imaging technology for intracoronary diagnostics.

Arteriosclerosis↗
PubMed1996

DNA ploidy analysis of mucinous cystic tumors of the pancreas. Correlation of aneuploidy with malignancy and poor prognosis.

BACKGROUND: Benign and malignant pancreatic mucinous tumors differ in proliferative activity, production of tumor markers, and expression of growth factors. DNA ploidy is a useful index of aggressiveness and poor survival in ductal adenocarcinoma, but has not been studied in pancreatic cystic tumors. METHODS: The DNA ploidy status of Fuelgen-stained tissue sections of pancreatic mucinous cystic tumors was evaluated by image cytometry and related to clinical outcome obtained by case record review. RESULTS: Ploidy status correlated with malignancy and poor clinical outcome. All benign mucinous cystadenomas (n = 13) were diploid and cured by resection. Patients with diploid cystadenocarcinomas (n = 6) had an 83% survival rate following resection, while patients with aneuploid cystadenocarcinomas (n = 5) all died (four of disease and the fifth of another cause). The difference in survival between the diploid and aneuploid carcinomas was significant (P = 0.04). CONCLUSIONS: DNA ploidy status of pancreatic mucinous tumors by image analysis provides quantifiable information that may be predictive of clinical outcome. DNA aneuploidy appears to be a significant differential factor in pancreatic mucinous tumors and is associated with shortened survival in mucinous cystadenocarcinomas.

Adult↗
PubMed1996

Proliferation tissue polypeptide antigen distinguishes malignant mucinous cystadenocarcinomas from benign cystic tumors and pseudocysts.

BACKGROUND: Cystic lesions of the pancreas include inflammatory pseudocysts, serous cystadenomas, and mucinous cystic tumors, some of which are malignant. Previous studies have shown that malignant mucinous tumors differ from benign pancreatic cysts in proliferative activity, secretion of tumor markers, and expression of growth factor receptors. Analysis of aspirated cyst fluid for tumor markers, viscosity, and cytologic examination has been proposed as an aid to preoperative differential diagnosis. Tissue polypeptide antigen (TPA) is a soluble proliferation antigen produced by rapidly dividing tissues, including conventional ductal pancreatic carcinoma. TPA levels in pancreatic cyst fluids have not been reported. METHODS: Tissue polypeptide antigen levels were determined in 46 pancreatic cyst fluids using a commercial immunoassay technique. RESULTS: Mucinous cystadenocarcinomas exhibited significantly higher levels of cyst fluid TPA than benign cystic lesions, including pseudocysts, serous cystadenomas, and benign mucinous cystadenomas (mean 910,672 U/mL, median 300,900 U/mL, range 16,600 to 4,210,000 U/mL for malignant mucinous cystadenocarcinomas; versus mean 16,082 U/mL, median 2,455 U/mL, range 0 to 155,000 U/mL for benign cystic lesions considered as a group; P < 0.0002). In 75% of the malignant cysts, the TPA values were in excess of 100,000 U/mL. Pseudocysts exhibited the lowest TPA levels (mean 2,108 U/mL, median 604 U/mL, range 0 to 20,240 U/mL) and were significantly lower than the values observed in cystic tumors (P < 0.0005). Serous and benign mucinous tumors had intermediate levels of TPA. CONCLUSIONS: Elevated levels of the proliferation antigen TPA in malignant pancreatic cysts correlate with earlier observations of increased proliferative activity and overexpression of growth factor receptors in these tumors. The TPA measurement may be a useful addition to previously reported cyst fluid markers to aid in preoperative differential diagnosis. Markedly elevated or very low values indicate a malignant or benign cyst, respectively.

Antigens, Neoplasm↗
PubMed1996

Carotid Doppler ultrasound criteria for internal carotid artery stenosis based on residual lumen diameter calculated from en bloc carotid endarterectomy specimens.

BACKGROUND AND PURPOSE: Carotid duplex ultrasound is widely used to screen patients for carotid endarterectomy and if combined with MR angiography and transcranial Doppler may be an alternative to conventional angiography in the preoperative assessment. We have examined the correlation between Doppler velocities and the residual lumen diameters of internal carotid arteries from surgical pathological specimens to establish Doppler criteria for residual lumen diameter independent of percent stenosis. METHODS: Ninety-one patients who underwent 99 carotid endarterectomies for internal carotid artery stenosis within 6 months of their carotid duplex ultrasound evaluation were studied. The endarterectomy specimens were removed en bloc, and the minimal residual lumen diameter was calculated by computer analysis. The sensitivity and specificity of the Doppler criteria for determining high-grade stenosis were calculated and receiver-operator curves generated. RESULTS: Peak systolic velocity (PSV), end-diastolic velocity (EDV),and carotid index (peak internal carotid artery velocity/ common carotid artery velocity) correlated with the residual lumen diameter. PSV > 440 cm/s, EDV > 155 cm/s, or carotid index > 10 indicated a residual lumen diameter of < or = 1.5 mm (specificity of 100% and sensitivity of 58%, 63%, and 30%, respectively). When these criteria were combined, the sensitivity increased to 72%. A PSV > 200 cm/s combined with either an EDV > 140 cm/s or a carotid index > 4.5 has a sensitivity of 96% and a specificity of 61%. CONCLUSIONS: Doppler criteria can be both specific and sensitive for detecting a significant stenosis, defined as a < or = 1.5 mm residual lumen diameter. By adjustment of the velocity criteria, it can be 100% specific or a highly sensitive test (96%).

Blood Flow Velocity↗
PubMed1995

Relation of epidermal growth factor receptor and estrogen receptor-independent pS2 protein to the malignant transformation of mucinous cystic neoplasms of the pancreas.

OBJECTIVE: To evaluate the role of epidermal growth factor receptor (EGF-R) and pS2 protein in the evolution of malignancy in mucinous cystic tumors of the pancreas. BACKGROUND: Mucinous cystic tumors of the pancreas include histologically benign but premalignant mucinous cystic neoplasms and mucinous cystadenocarcinoma. The molecular events leading to transformation from a benign to a malignant mucinous tumor are not known. Overexpression of EGF-R and detection of an estrogen-induced protein (pS2) has been demonstrated in ductal adenocarcinomas of the pancreas, but these factors have not been evaluated in mucinous cystic tumors. DESIGN: Twenty-six mucinous tumors were examined for EGF-R, pS2 protein, and estrogen and progesterone receptors. RESULTS: Eight (61.2%) of 13 malignant tumors exhibited increased expression of EGF-R, whereas EGF-R was not detected in any of the 13 benign tumors (P = .002). The pS2 protein was detected in nine of 11 malignant and 11 of 11 benign tumors (P = .480). Estrogen and progesterone receptors were not detected in the epithelium of either tumor type. The median survival time of the patients with EGF-R-negative tumors was 29.0 months compared with 14.5 months for those with EGF-R-positive tumors, but this difference did not reach significance owing to the small population size. CONCLUSIONS: Overexpression of EGF-R in mucinous cystic tumors, as in ductal adenocarcinomas, may be an important feature associated with malignancy and may have prognostic significance. Failure to detect EGF-R in histologically benign epithelium suggests that the upregulation of EGF-R may be important in the evolution of aggressive behavior. The expression of pS2 protein appears to be independent of estrogen and may play a role in the proliferative activity of mucinous tumors. However, pS2 expression is not a feature associated exclusively with malignancy.

Carcinoma, Ductal, Breast↗
PubMed1995

Intercellular adhesion molecule-1 induction: a sensitive and quantitative marker for cardiac allograft rejection.

OBJECTIVES: Rats with abdominal heterotopic heart transplants were studied to determine whether cardiac allograft rejection could be assessed by immunoscintigraphy targeting intercellular adhesion molecule-1 (ICAM-1), which was induced on allografted organ cells in association with rejection. BACKGROUND: It is important to detect early rejection before development of myocyte necrosis. Although a variety of methods for the detection of cardiac rejection have been investigated, histologic inspection of biopsied samples is still used routinely for clinical diagnosis of rejection. METHODS: DA rat (RT-1a) hearts were transplanted into PVG rats (RT-1c). Immunohistologic examination of the allografts demonstrated that ICAM-1 induction on vascular endothelial cells was observed as early as 4 days after transplantation in this combination. Thirty-nine allografted rats and seven isografted rats were studied. One day after injection of 100 microCi of 111Inlabeled anti-ICAM-1 monoclonal antibody (1A29), planar images were obtained. RESULTS: Rejecting allografts showed increased radiotracer uptake and could be identified on the images as early as 5 days after transplantation. In contrast, nonrejecting cardiac allografts and isografts did not show specific uptake. Mildly rejecting allografts, with mononuclear cell infiltration but without significant myocyte necrosis, could be scintigraphically identified, and the level of radiotracer uptake reflected the histologic severity of rejection. Accumulation of 111In-labeled monoclonal antibody of isotype-matched irrelevant specificity was not detected in the rejecting allografts. CONCLUSIONS: These data indicate that ICAM-1 induction can be assessed quantitatively by radioimmunoscintigraphy. Radioimmunoscitigraphy is a sensitive method for early detection and assessment of cardiac allograft rejection.

Abdomen↗
PubMed1995

Optical biopsy and imaging using optical coherence tomography.

Optical coherence tomography is a new imaging technique that can perform high-resolution, micrometre-scale, cross-sectional imaging in biological systems. The technology has been developed, and reduced to, preliminary clinical practice in ophthalmology. The challenging problem that OCT may address is the development of 'optical biopsy' techniques. These techniques can provide diagnostic imaging of tissue morphology without the need for excision of specimens. Many investigations remain to identify optimal areas for clinical application, and additional engineering must be done to integrate vertically the technology and to reduce it to clinical practice. Nevertheless, preliminary studies indicate the feasibility of developing this technology for a wide range of clinical and research diagnostic imaging applications. The ability to non-excisionally evaluate tissue morphology using a catheter or an endoscope could have a significant impact on the diagnosis and management of a wide range of diseases.

Arteries↗
PubMed1995

SR-Ca2+ ATPase as an autoimmunogen in experimental myocarditis.

The concept of autoimmunity in the pathogenesis of myocarditis or dilated cardiomyopathy is gaining impetus. Since systolic functional impairment and subsequent recovery are frequently observed in myocarditis, we reasoned that the development of autoimmunity to cardiac sarcoplasmic reticulum calcium ATPase (SR-Ca2+ ATPase), which could interfere with intracellular calcium regulation and therefore affect myocardial contractility, should lead to immune-mediated myocarditis in experimental animals. Murine monoclonal antibody 4C11-20.21 (IgM class) generated against canine cardiac SR-Ca2+ ATPase inhibits the cardiac but not the skeletal ATPase activity. Immunization of CAF1/J mice with 4C11-20.21-affinity-column-purified cardiac SR-ATPase produced a time-dependent induction of myocardial injury consistent with the diagnosis of myocarditis. Furthermore, the antibody 4C11-20.21 alone can induce myo-necrosis in severe combined immunodeficiency (SCID) mice indicating a mechanism of cardiomyopathy independent of the cytotoxic T-cell mediated autoimmunopathy. Administration of 4C11-20.21 into immunocompetent CAF1/J mice resulted in minimal myocardial abnormality (40% with perivascular and/or interstitial mononuclear lymphoplasmacytoid aggregates, 10% with borderline myocarditis and 10% with lesions consistent with focal myocarditis). All control animals had normal hearts. Immunoperoxidase electron microscopic examination of the involved cardiac tissues showed antibody localization in the subsarcolemmal myotubular system and focal staining of the immediately adjacent sarcolemma in mice injected with 4C11-20.21 but not with 2C12.1B5. The time-dependent association between cardiac SR-Ca2+ ATPase administration and development of myocardial lesions, as well as potentiated induction of myonecrosis with anti-cardiac SR-Ca2+ ATPase antibody in SCID relative to immunocompetent mice, suggest a potential autoimmunopathogenic role of cardiac SR-Ca2+ ATPase in experimental myocarditis.

Animals↗
PubMed1995

Cyst fluid NB/70K concentration and leukocyte esterase: two new markers for differentiating pancreatic serous tumors from pseudocysts.

Cystic lesions of the pancreas include inflammatory pseudocysts, serous cystadenomas, and mucinous tumors, some of which are malignant. Preoperative clinical and radiological parameters are unreliable and may result in incorrect diagnosis and inappropriate treatment. Cyst fluid analysis for cytology, viscosity, carcino-embryonic antigen, CA 72-4, and CA 15-3 will distinguish mucinous from nonmucinous lesions and usually help in determining malignancy. Currently, there is no reliable method to differentiate inflammatory pseudocysts from serous cystadenomas. This distinction is important because the treatment of these two lesions is different; pseudocysts are either observed or drained, whereas serous tumors are usually resected. The tumor marker NB/70K was measured in aspirated cyst fluid from 13 inflammatory pseudocysts and 11 serous cystadenomas by a commercial immunoassay. Leukocyte esterase was measured using Chemstrip SG urine test strips and amylase and lipase on a routine chemistry analyzer. The cyst fluid NB/70K concentration was significantly higher in pseudocysts (mean, 555 U/ml; range, 42-1,926 U/ml) than in serous cystadenomas (mean, 12 U/ml; range 0-130 U/ml) and this difference was significant (p < 0.0002). Leukocyte esterase was detected in 7 of 11 pseudocysts but was absent in 10 of 10 serous tumors (p = 0.002). Amylase and lipase values were generally higher in pseudocysts but these markers were unreliable due to marked outliers. Cyst fluid NB/70K and leukocyte esterase are promising markers to help differentiate pseudocysts from serous tumors on percutaneous aspirates. When combined with previously reported cyst fluid parameters (amylase, lipase, cytology, and amylase isoenzymes), these two cystic lesions can be reliably distinguished.

Antigens, Neoplasm↗
PubMed1995

T2-weighted contrast for NMR characterization of human atherosclerosis.

We sought to determine whether 1H NMR images without chemical-shift selection can adequately characterize the components of human atheromatous arteries. NMR, as a nondestructive, biochemical imaging tool, has the potential to identify lipids in atherosclerotic plaques but has not yet produced detailed images of atheroma components. Using 1H NMR spectroscopy at 9.4 T, we examined microdissected components of diseased and normal arteries to determine water relaxation constants (T1 and T2) as well as the relative content of mobile lipid. Relaxation times were also measured at 1.5 and 4.7 T. Sections of arteries with atherosclerotic lesions of graded severity were imaged at 1.5 and 9.4 T. The contrast-to-noise ratio (CNR) was used to assess lesion conspicuity. In the atheromatous core, the water NMR signal predominates over that of lipid (lipid-to-water ratio, 0.11). At 9.4 T, T2 is 20.2 ms for the atheromatous core, 30.1 ms for the collagenous cap, and 29.5 ms for normal media. This results in a high CNR on T2-weighted (T2w) images for atheromatous core compared with the collagenous cap and normal media. A similar contrast was measured at lower field strength. Calcifications do not generate appreciable signal due to their low water content but can be detected on T1-weighted (T1w) images. The water T2 contrast allows discrimination of the atheromatous lipid core from collagenous regions. The combination of T1w and T2w sequences permits in vitro identification of the atheromatous core, collagenous cap, calcifications, media, adventitia, and perivascular fat. The discrimination of collagen fibers that overlie lipid deposits permits study of plaque protection and stability at all field strengths and may provide the basis for in vivo microscopy of human atherosclerosis.

Adult↗
PubMed1994

Scintigraphic detection of early cardiac rejection by iodine 123-labeled monoclonal antibody directed against monomorphic determinant of major histocompatibility complex class II antigens.

Although it has been shown that early cardiac rejection can be visualized by radioimmunoscintigraphy targeting major histocompatibility complex class II antigen, the use of antibodies that bind to a polymorphic determinant of class II antigen has certain disadvantages for clinical application. This investigation was designed to examine the feasibility of scintigraphic detection of cardiac allograft rejection by using a monoclonal antibody that reacts with a monomorphic determinant of rat IA antigens. Twenty PVG rats (RT1c) and five DA rats (RT1a) underwent heterotopic transplantation with DA hearts. Two of the 20 allografted rats were treated with FK506 (2 mg/kg/day). Seventeen rats were injected intravenously with 80 microCi of iodine 123-labeled monoclonal antibody reactive with a monomorphic determinant of rat major histocompatibility complex class II antigens (Ox6) 16 hours before scintigraphy, and images were compared with those obtained by injection of 123I-labeled monoclonal antibody against a polymorphic determinant of class II antigens (F17-23-6, anti-RT1a) (n = 8). Background activity was higher in rats injected with Ox6 than in rats injected with F17-23-6. Uptake of labeled Ox6 in the grafts reflected the severity of rejection as determined by histopathologic criteria. Rejecting allografts with lymphocyte infiltration but without myocyte necrosis could be identified by the scintigraphy with use of labeled Ox6.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Cyst fluid cytologic analysis in the differential diagnosis of pancreatic cystic lesions.

Pancreatic cystic lesions include inflammatory pseudocysts, benign serous cystadenomas, and mucinous neoplasms, some of which are malignant. Cytologic analysis of cyst fluid has been proposed to diagnose pancreatic cysts before definitive therapy. The authors report an analysis of 31 pancreatic cyst aspirates: 9 pseudocysts, 5 serous cystadenomas, 8 mucinous cystic neoplasms, 4 mucinous cystadenocarcinomas, 2 papillary cystadenocarcinomas, 1 mucinous ductal adenocarcinoma with cystic degeneration, and 2 cystic islet cell tumors. All pseudocysts were correctly classified as probable inflammatory lesions, because of the presence of abundant acute inflammation and histiocytes and the absence of glandular epithelium. Three of five serous cystadenomas were correctly classified, based on the presence of small cuboidal cells in clusters with microvesicular cytoplasm containing glycogen. Eleven of 12 mucinous tumors contained round cells with large cytoplasmic mucin vacuoles or columnar cells containing cytoplasmic mucin. Malignancy was diagnosed in 5 of 7 carcinomas, 1 case was classified as suspicious for malignancy, and 1 case was nondiagnostic because of the absence of a cellular component. The authors concluded that pancreatic cyst fluid cytologic analysis is useful in differentiating mucinous from nonmucinous pancreatic cysts and may provide definitive evidence of malignancy. In some cases, serous cystadenoma can be diagnosed based on cytologic analysis. An inflammatory smear without epithelial cells suggests a pseudocyst, but these findings are nonspecific, as a similar pattern may occur when a cystic neoplasm undergoes degenerative changes. Therefore, pseudocyst remains a diagnosis of exclusion.

Biopsy, Needle↗