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G H Yu

Publications and source records attributed to G H Yu.

At least 37 records · Page 2Linked to original sources
PubMed1999

Difficulties in the fine needle aspiration (FNA) diagnosis of schwannoma.

The results of nine FNAs of eight histologically proven schwannomas are presented. In only one of the aspirates was a diagnosis of schwannoma made; three additional cases were diagnosed as 'spindle cell neoplasm'. Two of the cases were considered to be non-diagnostic due to hypocellularity, while two cases containing cellular material raised the differential diagnosis of granulation tissue and granulomatous inflammation due to the presence of epithelioid cells and an inflammatory infiltrate, and are illustrated here. The remaining FNA was felt suggestive of branchial cleft cyst due to the presence of only cystic fluid in a neck mass. We observe that: (i) the acquisition of an adequate, representative specimen via FNA is often difficult in schwannoma, and (ii) diagnostic difficulties may be encountered in cases in which cellular material is obtained.

Adult↗
PubMed1999

Evaluation of histochemical methods for the detection of intracytoplasmic mucin in serous effusions.

We have studied 25 serous effusions containing definitive morphologic evidence of adenocarcinoma to evaluate the ability of two mucin stains (Mayer's mucicarmine, D-PAS) to detect intracytoplasmic mucin in both cytologic (cytospin) and corresponding histological (cell block) preparations. Mucicarmine stain was positive in six of 25 (24%) cytospins and 13 of 25 (52%) cell blocks. D-PAS was positive in 19 of 25 (76%) cytospins and 20 of 25 (80%) cell blocks. Eight cases were identified which showed mucicarmine positivity in the cell block but not the corresponding cytospin; prolonging incubation time resulted in a positive mucicarmine in cytospin preparations for seven of these cases. We conclude that: (i) D-PAS is a more sensitive stain for the detection of intracytoplasmic mucin in all preparations; (ii) mucicarmine shows preferential staining for cell blocks; (iii) alterations in the staining protocol may permit mucin detection by mucicarmine staining in cytologic preparations in a significant number of cases.

Adenocarcinoma↗
PubMed1999

Follicular variant of papillary carcinoma. Cytologic and histologic correlation.

The cytologic diagnosis of follicular variant of papillary thyroid carcinoma (FVPTC) can be difficult owing to the paucity of nuclear changes of papillary carcinoma and overlapping features with other follicular-derived lesions. We report our fine-needle aspiration (FNA) experience with 17 histologically proved cases of FVPTC with a preceding FNA. All cases showed increased cellularity and a background of moderate to abundant thin watery colloid with variable amounts of thick eosinophilic colloid. The cells were arranged mainly in monolayer sheets and syncytial fragments; occasional microfollicle formation with abundant fine eosinophilic cytoplasm was seen. Nuclear enlargement was a consistent finding in all cases. Only 5 cases showed prominent nuclear features of papillary carcinoma. Histologic examination showed encapsulated follicular-patterned nodules with multifocal random distribution of nuclear features of papillary carcinoma that were more pronounced in the subcapsular locations of the lesions. This morphologic heterogeneity explains the variability seen in FNA specimens of FVPTC and may result in false-negative diagnoses. We believe that these findings should be considered when interpreting follicular lesions; suspicion of an FVPTC should be conveyed in the cytopathology report, which may prompt intraoperative assessment to avoid a second surgical intervention for completion thyroidectomy.

Adult↗
PubMed1999

Characterization of MdMADS2, a member of the SQUAMOSA subfamily of genes, in apple.

A MADS-box gene, MdMADS2, was isolated from the apple (Malus x domestica Borkh.) var Fuji and its developmental expression pattern was studied during flower development. MdMADS2 shares a high degree of amino acid sequence identity with the SQUAMOSA subfamily of genes. RNA blot analysis showed that MdMADS2 is transcribed through all stages of flower development, and its transcription was seen in the four floral organs. RNA in situ hybridization revealed that the MdMADS2 mRNA is expressed both in the inflorescence meristem and in the floral meristem. The MdMADS2 transcript was detected at all stages of flower development. Protein localization analysis showed that MdMADS2 protein was excluded from the stamen and carpel primordia, in which a considerable MdMADS2 mRNA signal was detected. This indicates that posttanscriptional regulation may be involved in the MdMADS2-mediated control of flower development. Transgenic tobacco expressing the MdMADS2 gene from the cauliflower mosaic virus 35S promoter showed early flowering and shorter bolts, but did not show any homeotic changes in the floral organs. These results suggest that MdMADS2 plays an important role during early stages of flower development.

Amino Acid Sequence↗
PubMed1998

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.

Adult↗
PubMed1998

Follow-up of atypical glandular cells in cervical-endocervical smears.

Atypical glandular cells of undetermined significance (AGUS) is a diagnostic category of the Bethesda system encompassing glandular-type cells that show either endometrial or endocervical differentiation and display greater atypia than expected for a reactive process but do not meet the criteria for invasive adenocarcinoma. We investigated AGUS in a follow-up study of cervical-endocervical smears with either histology or repeat cytology follow-up. From the cytology files at Northwestern Memorial Hospital over a 4-year period, 136 cervical-endocervical smears were diagnosed with AGUS, which were further subdivided into atypical glandular cells, unqualified (AGC-U); atypical glandular cells, favor reactive (AGC-FR); or atypical glandular cells, favor neoplasia (AGC-FN). Of 96 cases with either histologic or cytologic (cervical-endocervical smear) follow-up, 39 cases of AGC-U had a variety of diagnoses on follow-up, with mostly benign entities in 72% and squamous intraepithelial lesions in 28%. Follow-up of the 36 cases of AGC-FR also demonstrated mostly benign entities (82%) and five cases of squamous intraepithelial lesions. The largest number of premalignant and malignant diagnoses (48%) was found during follow-up of patients with an initial diagnosis of AGC-FN, including the only two cases of adenocarcinoma in situ in our study. In conclusion, our study confirms that AGUS encompasses a wide spectrum of diagnoses, most of which prove to be benign. Subclassification of these cases into "favor reactive" and "favor neoplasia" was found to be helpful in predicting the follow-up status of these patients. However, the small but distinctive percentage of preneoplastic and neoplastic diagnoses seen on follow-up warrant further diagnostic procedures and/or close monitoring in patients with this diagnosis.

Adenocarcinoma↗
PubMed1998

Fine-needle aspiration of thyroid: an institutional experience.

In this report we describe our institutional experience with fine-needle aspiration (FNA) of the thyroid. Six hundred sixty-two FNAs were performed in 616 patients in a 3 1/2 year period. The cytological diagnoses were categorized as: negative for malignancy, 455 (69%); indeterminate, 30 (4%); neoplasm/malignant, 105 (16%), and nondiagnostic, 72 (11%) including 29 cases from outside institutions. Surgical follow-up was available in 140 (21%) cases, 95 of which had preceding cytological diagnoses of positive or indeterminate for neoplasm/malignancy. For those cases with definite benign or neoplastic/malignant cytodiagnosis, a sensitivity of 92% and specificity of 84% was achieved. The cumulative false-positive and false-negative rates for these categories were 16% and 7.5%, respectively. On comparing discrepant diagnosis between cytological and histological specimens, two major factors were identified as causes for diagnostic misinterpretations: overlapping cytological features among follicular-derived lesions and inadequate/suboptimal specimens. The cytological features of follicular variant of papillary carcinoma were found to overlap those of hyperplastic/adenomatous nodules and follicular neoplasms due to the presence of abundant thin colloid, monolayer sheets of follicular cells and subtle nuclear features of papillary carcinoma. We suggest that awareness of variable cytological features in follicular lesions (especially in follicular variant of papillary carcinoma), following strict criteria of specimen adequacy in thyroid FNA, and clinicopathological correlation can markedly reduce false-negative results.

Adolescent↗
PubMed1998

Tumor cell (dys)cohesion as a prognostic factor in aspirate smears of breast carcinoma.

As the ability of fine-needle aspiration biopsy to separate benign from malignant lesions approaches its limits, the potential to provide additional prognostic information based on these same specimens has received increasing attention. An area we have pursued is based on the recognized finding that many neoplastic cells exhibit altered expression of intercellular adhesion molecules. In this study, we evaluated a large number of preoperative fine-needle aspiration smears (83 cases) of histologically proven primary breast ductal carcinoma in an attempt to correlate the degree of cellular dyscohesion in the aspirate with the presence of local (ipsilateral axillary lymph node) metastases. We found that although the smear pattern of primary tumors greater than 3 cm showed no correlation with the presence of positive axillary nodes, the degree of tumor cell dyscohesion of tumors less than 3 cm (60 cases) as seen in aspirate smears did correlate with the presence of regional metastases. Poorly cohesive primary tumors were always associated with local metastases (4 of 4 cases, 100%) compared with those of intermediate (15 of 37 cases positive, 40%) and high cohesion (5 of 19 cases positive, 26%). Thus, we believe the evaluation of tumor cell (dys)cohesion in cytologic smears shows great promise as a simple, cost-effective technique to predict the biologic behavior of breast carcinoma.

Adenocarcinoma↗
PubMed1998

Diagnostic significance of 'benign pairs' and signet ring cells in fine needle aspirates (FNAs) of the breast.

Most breast mass lesions are readily characterized by FNA with cytodiagnosis. Occasionally, benign but markedly proliferative lesions are diagnostically difficult to separate from well differentiated malignancies. We present information pertaining to the diagnostic significance of two cytologic findings observed in breast aspiration specimens, namely pairs of stripped bipolar nuclei and signet ring cells (SRC). We have evaluated aspirate smears from 219 cases of histologically proven benign (n = 114) and malignant (n = 105) breast lesions. Both singlets and pairs of bipolar nuclei and SRC were enumerated, and their numbers were correlated to histological diagnosis. Closely associated pairs of stripped bipolar nuclei were found in 68% of benign lesions compared with only 3.8% of carcinomas, establishing their presence as a highly specific indicator of a benign process. Large numbers of such 'benign pairs' also favoured the diagnosis of fibroadenoma. SRC were identified in 66% of histologically proven carcinomas (67% of ductal and 70% of lobular). SRC were also present in 10% of histologically benign cases. In the malignant cases, SRC were most frequently noted in a single cell distribution or within small, loosely cohesive tissue fragments. In the benign instances, SRC were most commonly noted within large fragments, and many of these cells were proved by immunohistochemical reactions to be vacuolated myoepithelial cells. We conclude that the presence of bipolar nuclei in closely associated pairs suggests benignity and aids in the subclassification of benign breast masses. In addition, the presence of SRC does not aid in the classification of tumour subtype (ductal vs lobular), and the occurrence of such cells in the proper context should prompt surgical biopsy.

Adenocarcinoma↗
PubMed1997

Fine-needle aspiration of pigmented villonodular synovitis of the temporomandibular joint masquerading as a primary parotid gland lesion.

The fine-needle aspiration findings in a case of pigmented villonodular synovitis of the temporomandibular joint are presented. The characteristic cytomorphologic and clinical features of this uncommon, benign fibrohistiocytic lesion are discussed. In addition, due to the initial clinical impression of a primary parotid gland lesion, the differential diagnosis for the cytomorphologic features observed (histiocytoid cells admixed with osteoclast-like giant cells) are discussed within the context of a primary salivary gland mass.

Biopsy, Needle↗
PubMed1997

Diagnostic significance of signet ring cells in fine-needle aspirates of the breast.

Fine-needle aspiration (FNA) is a reliable and cost-effective procedure in the evaluation and management of breast lesions. One diagnostic dilemma that may sometimes arise is the finding of signet ring cells. The isolated finding of such cells in aspirate smears may be particularly problematic in cases of low cellularity or those with otherwise benign features. Although it is generally held that such cells are almost exclusively associated with carcinoma (particularly the lobular subtype), their significance in FNA smears has never been systematically evaluated. To establish their diagnostic utility, we evaluated aspirate smears from 150 cases of histologically proven benign (77) and malignant (73) breast lesions for the presence of signet ring cells, defined as those containing a prominent intracytoplasmic vacuole with nuclear displacement. Signet ring cells were identified in 71% of malignant cases (75% of ductal carcinomas and 71% of lobular carcinomas), mostly as single cells or within small, loosely cohesive tissue fragments. Such cells also present in 6% of histologically proven benign lesions, most commonly within large tissue fragments. Many of these cells were proven to be vacuolated myoepithelial cells, based on histologic correlation and immunostaining results using anti-muscle-specific actin. On the basis of these findings, we conclude that (1) the presence of signet ring cells within small loose tissue fragments or as single cells in FNA smears should prompt close clinical follow-up (including repeat FNA and perhaps surgical biopsy), regardless of smear cellularity, (2) the presence of signet ring cells in cases of adenocarcinoma does not predict a particular tumor subtype, and (3) rare benign breast lesions may contain signet ring cells, particularly within large tissue fragments, and do not, in isolation, warrant surgical biopsy to exclude malignancy.

Adenocarcinoma↗
PubMed1997

Modified interphase cytogenetics technique as an adjunct in the analysis of atypical cells in body fluids.

Our objective was to determine the value of a modified interphase cytogenetics technique (MICT) by fluorescence in situ hybridization (FISH) in the study of atypical cells in body fluids in previously stained slides, allowing a direct morphologic-cytogenetic correlation. Thirty-five cases (29 bladder washes, four pleural fluids, two ascitic fluids) initially diagnosed as "atypical" with subsequent histologic confirmation were included. Histologically, there were 25 malignant four dysplastic, and six benign lesions. Previously Papanicolaou or Diff-Quick-stained slides were marked to determine the location of the cells of interest prior to FISH analysis. A pretreatment modification using pepsin digestion was utilized. Chromosome-specific probe 8 (Vysis) was used to detect numerical chromosomal abnormalities (NCA) involving chromosome 8. Various NCA (aneuploid) were detected in the atypical cells of histologically proven malignant cases but not in the benign cases. Using histology as a "gold standard," FISH has a sensitivity of 83% and a specificity of 100%. In conclusion this study shows that a MICT by FISH on previously stained slides can serve as an adjunct in the study of atypical cells in body fluids. This technique allows a direct morphologic-cytogenetic correlation which in the future may aid in the better understanding of carcinogenesis.

Body Fluids↗
PubMed1997

Thymic epithelial cells as a diagnostic pitfall in the fine-needle aspiration diagnosis of primary mediastinal lymphoma.

The cytologic diagnosis of primary mediastinal lesions is challenging due to the large number of lesions which may arise (i.e., lymphoma, thymoma, germ cell tumor), often with overlapping cytomorphologic features. We present an instructive case of primary mediastinal non-Hodgkin's large-cell lymphoma with sclerosis, entrapping thymic epithelium. Preoperative fine-needle aspiration yielded predominantly epithelial fragments and few lymphoid cells leading to the cytologic misdiagnosis of thymoma. The entity of primary mediastinal large-cell lymphoma (LCL) is discussed and correlated with the cytologic features seen. In addition, histologic sections from 15 additional cases of primary mediastinal LCL were evaluated to determine the frequency with which significant numbers of epithelial fragments may be observed.

B-Lymphocytes↗
PubMed1996

Cytomorphology of progressive multifocal leukoencephalopathy (PML): review of sixteen cases occurring in HIV-positive patients.

Progressive multifocal leukoencephalopathy (PML) is a fatal demyelinating disorder of the central nervous system (CNS) resulting from infection of oligodendrocytes by JC virus. Although all patients immunocompromised by any congenital, acquired, or iatrogenic condition are at risk, the population which currently accounts for the majority of new cases is that infected with the human immunodeficiency virus (HIV). Though the clinical/radiologic presentation is characteristic, biopsy confirmation is necessary, as these patients are at risk for other primary CNS disorders which may produce similar clinical findings. Immediate assessment of tissue adequacy by cytologic smear is generally preferred in these specimens due to its relative reduced risk of disease transmission when compared to conventional frozen section. We report here the cytologic findings seen in touch imprints and squash preparations of 16 cases of PML, all occurring in HIV-positive patients and obtained by stereotactic guided needle biopsy. Typical cytomorphologic findings are described and correlated with histologic sections. In addition, features useful in the exclusion of other differential diagnostic possibilities are discussed.

Adult↗