Internal quality assurance in cervical cytology—one laboratory's experience

The results of an internal quality assurance exercise in one cervical cytology laboratory in England are presented, using differing types of partial percentage re-screening of cervical smears. An overall false-negative dyskaryotic rate of up to 4.3% was demonstrated, with the final cytology report diagnosis differing from the primary screening diagnosis in 1.3% of cases. These findings are discussed, with the aim of helping to foster debate on the setting of national laboratory internal quality assurance standards.     

Fine Needle Aspiration Cytology of High Grade T-Cell Lymphomas In Human T-Lymphotropic Virus Type 1 Carriers

We studied the fine needle aspiration (FNA) cytology of high grade peripheral T-cell lymphomas from eight human T-lymphotropic virus-1 (HTLV-1) positive patients. FNA smears from seven lymphomas showed a distinctive cytologic pattern with a dominance of rounded cells with irregular nuclei and a moderately basophilic cytoplasm. Irregular cells with a pale abundant cytoplasm were present in varying amounts. Some smears contained a few giant cells with cerebriform nuclei. In addition, plasma cells and eosinophils were found. Epithelioid cells were an inconstant finding. On histology these seven lymphomas were assigned to the pleomorphic medium-large cell subtype and all but one were of T-helper phenotype with rearrangements of the T-cell receptor. FNA smears from a lymph node in a patient with a previous histological diagnosis of lymphomatoid papulosis of the gingiva showed a monotonous pattern of large immunoblastic cells with some binucleated variants consistent with a diagnosis of high grade immunoblastic lymphoma, which was confirmed histologically. Our results show that peripheral T-cell lymphomas from HTLV-1 positive patients have cytological patterns which are distinctive enough to allow a conclusive diagnosis of high grade T-cell lymphoma. However, we do not think that the cytology of HTLV-1 positive lymphomas can be differentiated from that of virus-unrelated high grade T-cell lymphomas.     

The use of an automated image cytometer for screening and quantitative assessment of cervical lesions in the British Columbia Cervical Smear Screening Programme

The use of an automated image cytometer for screeing and quantitative assessment of cervical lesions in the British Columbia Cervical Smear Screening Programme
The development of an automated device to screen cervical cytology slides for the detection of pre-invasive lesions of the cervix has been the goal of many individuals for over 30 years. The increasing sophistication of the technology of automation and increasingly powerful computer technology have enabled a number of these systems to reach the stage at which they have become a practical reality. The Department of Cancer Imaging at the British Columbia Cancer Agency has developed such a device over the past few years. This study reports the preliminary results of a trial to determine the reliability of the device for the screening and quantitative assessment of cervical cells. A training set of over 1000 cervical slides was used to train the image cytometer. A test set of 1030 slides was screened by the image cytometer and in the Cytology Screening Laboratory. At the 50% sample split the sensitivity of the image cytometer was 95% for severe dysplasia and 90% for moderate dysplasia, compared with a sensitivity of 90% for both of these lesions using conventional screening. A combination of nuclear texture features was found which can be used for the quantitative assessment of both abnormal cells and apparently normal intermediate cells.     

Photopolymerized 2-Hydroxyethylmethacrylate as a mounting medium preserving immunocytochemical reaction and nuclear counterstain

Immunocytochemical or cytoenzymological techniques often make use of coupling reactions between a substituted naphtol and a diazonium salt. A positive reaction results in an azo dye precipitate. Unfortunately, this precipitate is easily soluble in alcohols and organic solvents. Thus, usual mounting media are not usable and permanent preparations cannot be obtained. A stable mounting medium such as Apathy's syrup can be used, but nuclear counter-staining disappears in a few days. We tested the hydrophilic monomer 2-hydroxyethylmethacrylate, containing various photopolymerizing agents, as a permanent mounting medium. 2-2 Dimethoxy 2-phenyl acetophenone proved to be the most useful photopolymerizer. The cytocentrifugation slides must be dried before mounting to avoid recrystallization artifacts. The azo dye precipitate and nuclear counterstaining can be preserved perfectly long-term. The cost of these media is very low.     

Management of Sonographically Suspicious Thyroid Nodules 1 cm or Smaller and Candidacy for Active Surveillance: Experience of a Tertiary Center in China

ObjectiveOur objective was to investigate the management of patients with asymptomatic suspicious thyroid nodules ≤1 cm.MethodsWe retrospectively reviewed medical records of patients with sonographically suspicious thyroid nodules ≤1 cm and without distant metastases, suspicious lymph node metastasis (LNM), or extrathyroidal extension (ETE).ResultsOf the 386 enrolled patients, 174 (45.1%) had immediate surgery (IS), while 212 (54.9%) underwent active surveillance (AS). In the IS group, 166 (95.4%) patients were confirmed as having papillary thyroid microcarcinoma. LNM and ETE were observed in 24.7% and 2.4% cases, respectively. In the AS group, nodule size increased by ≥3 mm in 11 (5.2%) patients and 39 (18.4%) had a >50% increase in nodule volume after a median follow-up of 12 months. Nodules with smaller volume at diagnosis were more likely to increase in volume later. Newly suspicious LNM was detected in 23 (10.8%) patients. Delayed surgery (DS) was performed in 101 patients, with 27 showing disease progression. ETE and LNM were detected in 3% and 36%, respectively, of patients with papillary thyroid microcarcinoma. Compared with IS, tumors in the DS group more frequently showed lateral LNM and capsular invasion (P < .05). No patient had recurrence or died of thyroid cancer during postoperative follow-up (median 26 [4-60] months).ConclusionsIS or DS of patients with asymptomatic suspicious thyroid nodules ≤1 cm was relatively high in China. The inertia of low-risk nodules and the effectiveness of DS for those that progressed make AS a feasible strategy.     

KARYOTYPES AND REPRODUCTIVE SEASONALITY OF THE GENUS BANGIA (RHODOPHYTA) IN BRITISH COLUMBIA,CANADA1

Chromosome number and morphology as well as reproductive seasonally were examined in Bangia populations collected from 88 sites along the British Columbia coasts. Sexual filaments were recorded at 35 sites and asexual filaments at 58. Four different types of Bangia were determined. These were characterized by reproductive state and chromosome number, as well as by their seasonally and range of distribution. A summer-fall three-chromosome sexual type occurred from approximately 50° N northward and a winter-spring four-chromosome sexual type had a northerly limit of approximately 54° N, extending to the southernmost areas of British Columbia. Two asexual types occurred, exhibiting little seasonally, six-chromosome populations throughout the coast and three-chromosome populations at three southerly sites only. Karyograms were prepared for the four chromosomal types, assigning tentative centromere locations. Somatic chromosome pairing was reported for the first time in the Rhodophyta.     

Karyomorphology of Taiwanese Begonia (Begoniaceae): taxonomic implications

 The karyomorphology of all 14 species of Taiwanese Begonia was investigated to elucidate their chromosome features and chromosomal evolution. Among all species investigated, differences in chromosome features are found in: (1) chromosome number 2n = 22, 26, 36, 38, 52, 60, 64, 82, and (2) frequencies of chromosomes with secondary, tertiary, and/or small constrictions of polyploids, ranging from 23% to 63%, which is higher than the expected value of about 9%. It is suggested that after polyploidization from the diploid species (i.e., 2n = 22 and frequencies of chromosomes with secondary, tertiary, and/or small constrictions of polyploids of about 9%), chromosome translocations occurred, followed by a decrease in chromosome number, and subsequently stabilized genomes were formed in various species in Taiwan. The karyomorphological evidence also suggested that the chromosome morphology has evolved in parallel in the begonias belonging to different sections in Taiwan. The variation in chromosomal features is more complex than the variation in floral and fruit morphologies. Karyomorphological data also supports the recognition of five new species in Taiwan: Begonia bouffordii, B. chuyunshanensis, B. pinglinensis, B. tengchiana, and B. wutaiana. Based on detailed karyomorphological analyses, the taxonomic implications, speciation, and chromosomal evolution in Taiwanese Begonia are discussed. Received: January 22, 2002 / Accepted: March 4, 2002     

Functional morphology of the midgut of a sandfly as compared to other hematophagous nematocera

The midgut epithelium of female Lutzomyia longipalpis was investigated by means of electron microscopic morphometry before and during blood digestion. Ultrastructure and cytological changes of the stomach cells upon blood feeding were generally similar to the ones described for Phlebotomus longipes (Gemetchu, 1974) and for mosquitoes (Hecker, 1977), In addition, the quantitative composition of the cells resembled the one of mosquitoes in many respects. Despite some morphological differences in the functional gut cytology, it can be admitted that, in general, digestive processes may run similarly in the midguts of sandflies and mosquitoes.     

The location of parasites within their hosts: Site selection by Trichuris muris in the laboratory mouse

Panesar T. S. and Croll N. A. 1930. The location of parasites within their hosts: site selection by Trichuris muris in the laboratory mouse. International Journal for Parasitology10: 261–273. This paper examines those factors which determine the location of T. muris in the caecum and colon of DBA-2 male mice. In caecectomized mice, infected post-operatively, T. muris established in the ileum. Despite the very different surface architecture of the ileum T. muris thrived within the epithelium lining the villi, comparable to their cytological microhabitat in the caecum. Unembryonated eggs of T. muris collected passively in the caecum, and embryonated eggs hatched readily in vitro when placed in caecal contents. These factors, together with the transit time of eggs which reached the caecum in 1 to 6 h, probably account for this being the major location for this nematode. T. muris could be successfully transplanted from caecum to caecum at 5 and 10 days post-emergence but not afterwards. This has been interpreted to result from the inability of the older worms to re-establish the intimate intra-epithelial association and to re-excavate their characteristic tunnels. T. muris caused a significant increase in the pH of luminal environment of the caecum and the colon of infected mice. The influence of post-operative changes in the gastrointestinal tract of mice causing compensatory anatomical changes is reviewed but considered to be insignificant in the present study.     

Conjunctival impression cytology in contact lens wearers

The upper tarsal conjunctiva is in constant friction with the surface of the contact lens. The conjunctival surfaces of 80 soft and gas-permeable contact lens wearers (40 each) and 20 controls were studied using biomicroscopy and impression cytology. A filter dissolution technique was used to process the conjunctival imprints. Biomicroscopic and cytologic grading of the conjunctivae was performed using four-tier grading systems. Impression cytology is a non-invasive, painless procedure. The altered technique of processing yielded better cellularity and excellent cellular detail. On biomicroscopy and cytology, all controls showed Grade 1 appearances. Soft lens wearers who were symptomatic were found to have a significant increase in both biomicroscopic and cytologic grades, when compared with their asymptomatic counterparts. No correlation was found between duration of lens use and biomicroscopic or cytologic grades. All changes were found to be more severe in soft lens wearers.