2,331 research outputs found
Role of FNAC with Histopathology in Head and Neck Lesions.
Fine Needle Aspiration Cytology as practiced to-day, is still a relatively new
discipline and no single pathologist can lay claim to the vast experience of its every facet.
The numerous case reports of all kinds of rare and exotic tumours and other pathological
processes diagnosed by fine needle aspiration cytology (FNAC) published in the cytology
journals create the impression that nothing is impossible for this technique.
As fine needle aspiration procedure being cost - effective, simple office procedure,
quick diagnosis at the first contact of patient and it can delineate between benign and
malignancy and can be repeated for definite confirmation on doubtful diagnosis.
We have taken up lesions of Head and Neck fine needle aspiration cytology in
comparison with histological correlation for available lesions like thyroid, lymphnode,
salivary glands and soft tissue tumours. Head and neck masses are common and the lesions
are varied, ranging from inflammation to neoplasms. Fine needle aspiration cytology helps
us to catagorise the lesions which require surgical intervention and those which do not.
FNB is of great assistance in the management of patients, since therapeutic decisions
can be made earlier and without the need for further diagnostic surgery. The diagnostic
accuracy of FNAC in suspected and recurrent and metastatic tumours is generally high.
Small nodal metastasis can be missed. By far the most common indication for FNB in the
head and neck is the investigation of suspected local recurrence or nodal metastasis of
previously diagnosed and treated cancer18.
FNAC being a minimally invasive technique is particularly suitable in this sensitive
area where an incisional biopsy may present problems. A preoperative cytological diagnosis
of a primary neoplasm may allow more rational planning of surgery. The anaplastic and
poorly differentiated lesions can be planned for palliative radiotherapy or chemotherapy.
Fine needle aspiration cytology of the thyroid gland is firmly established as a first
line of diagnostic test for the evaluation of pre operative diagnosis of thyroid lesions with
the combination of necessary laboratory tests20. The present study was undertaken to
evaluate the accuracy of FNAC in diagnosing both benign and malignant lesions and also to
correlate the cytologic diagnosis with histopathological findings.
Lymphadenopathy is a sign of inflammation, infection, primary or metastatic
malignant tumours. This is commonly seen involving the head and neck region. Their
persistence for a prolonged period of time, requires further investigation. In recent years
aspiration has become popular for the diagnosis and typing of "Lymphoma"23.
The salivary glands are eminently accessible to FNB and material is easily obtained.
The variety of lesions having diagnostic dilemma in salivary neoplasms are not uncommon.
Problems of pitfalls in FNAC diagnosis of salivary gland lesions have attracted
considerable interest in recent years..
The purpose of FNAC is not a substitute for histology and if it is used in conjunction
with clinical and radiological parameters it will provide the best initial assessment on which
management decisions can be based. It is true that the increasing use of ancillary
techniques such as, immunohistochemistry, electron microscopy, cytogenetics and
molecular biology techniques has significantly enhanced the potential to make precise type
specific diagnosis but they are expensive and not done as a routine, can be applied in
problem cases. Representativeness, adequacy and quality of preparation will always remain
"sine qua non" no matter how sophisticated the supplementary techniques18
Mature Cystic Teratoma with Squamous Cell Carcinoma-Rare Case Presentation
Introduction: Mature cystic teratomas are part of a subclass of ovarian germ-cell tumour believed to arise from the primordial germ cells. Ovarian germ-cell tumours account for around 20–25% of ovarian neoplasms and 5% of ovarian cancers. A secondary malignant transformation of the various tissue components of mature cystic teratoma can occur, typically in postmenopausal women. More than 80% of malignant transformations are squamous-cell carcinomas arising from the ectoderm; the rest are carcinoid tumours or adenocarcinomas. Methods and Methodology, Case Report: A 40-year-old postmenopausal patient came with lower abdominal pain past 2 months. The patient was submitted to a gynecological examination and to transvaginal ultrasound, which confirmed the presence of right adnexal mass measuring 11×8x 2 cm; the mass proved to have cystic features in association with intracystic fat, raising the suspicion of an ovarian teratoma. In addition, areas of acoustic shadowing were discovered, raising the suspicion of a Rokitansky nodule exhibiting solid components such as hair and teeth. Pelvic CT scan demonstrated right adnexal dermoid cyst causing mild hydroureteronephrosis. A total hysterectomy with bilateral adnexectomy was performed, and the specimen was submitted for histopathological examination. Histopathological examination revealed Mature Cystic Teratoma with Squamous Cell Carcinoma. Discussion: Ovarian teratoma develops from germ cells and might present different cellular types originating from one or more of the germ layers, represented by endoderm, ectoderm and mesoderm. Of this malignant transformation is about 1- 2 %. Malignant transformation of ovarian teratoma can arise from any type of germ cell that is present at the level of these tumors; therefore, adenocarcinomas, squamous cell carcinomas, sarcomas, melanomas, adenosquamous carcinomas or even carcinoid tumors might occur. Of this squamous cell carcinoma is common. Conclusion: Although ovarian teratomas are frequently encountered, a small proportion of them will develop further complications, such as infection or malignancy. In cases in which malignant transformation occurs, squamous cell carcinoma is the most commonly encountered type of malignancy. Novelty: Malignant transformation of mature cystic ovarian teratoma is a scarce eventuality, only rare cases being reported so far. Furthermore, the development of this transformation in the setting of an abscessed tumor is even scarcer
An Incidental Case of Neuroendocrine Tumor Case Report
Rectal neuroendocrine tumors (NETs), which have a 0.17% incidence, are rare. Despite the fact that improved detection rates are to blame for the current increase in NET incidence. Furthermore, it has been determined that the following elements significantly influence the tumor's capacity to spread: Proliferative index, depth of infiltration at diagnosis, and tumor size (1). When the tumor is detected at a low-grade proliferation stage, rectal NET offers the best prognosis of any NET type. Modern knowledge of the lesion's morphology, along with the additional use of ancillary studies, help diagnose NET as soon as possible so that the necessary management may be tailored
An Incidental Case of Neuroendocrine Tumor Case Report
Rectal neuroendocrine tumors (NETs), which have a 0.17% incidence, are rare. Despite the fact that improved detection rates are to blame for the current increase in NET incidence. Furthermore, it has been determined that the following elements significantly influence the tumor's capacity to spread: Proliferative index, depth of infiltration at diagnosis, and tumor size (1). When the tumor is detected at a low-grade proliferation stage, rectal NET offers the best prognosis of any NET type. Modern knowledge of the lesion's morphology, along with the additional use of ancillary studies, help diagnose NET as soon as possible so that the necessary management may be tailored
Statistics of leaders and lead changes in growing networks
We investigate various aspects of the statistics of leaders in growing
network models defined by stochastic attachment rules. The leader is the node
with highest degree at a given time (or the node which reached that degree
first if there are co-leaders). This comprehensive study includes the full
distribution of the degree of the leader, its identity, the number of
co-leaders, as well as several observables characterizing the whole history of
lead changes: number of lead changes, number of distinct leaders, lead
persistence probability. We successively consider the following network models:
uniform attachment, linear attachment (the Barabasi-Albert model), and
generalized preferential attachment with initial attractiveness.Comment: 28 pages, 14 figures, 1 tabl
Shaking a Box of Sand
We present a simple model of a vibrated box of sand, and discuss its dynamics
in terms of two parameters reflecting static and dynamic disorder respectively.
The fluidised, intermediate and frozen (`glassy') dynamical regimes are
extensively probed by analysing the response of the packing fraction to steady,
as well as cyclic, shaking, and indicators of the onset of a `glass transition'
are analysed. In the `glassy' regime, our model is exactly solvable, and allows
for the qualitative description of ageing phenomena in terms of two
characteristic lengths; predictions are also made about the influence of grain
shape anisotropy on ageing behaviour.Comment: Revised version. To appear in Europhysics Letter
Rosai Dorfman Disease - A Rare Presentation of Cervical Lymphadenopathy - A Case Report
Rosai Dorfman disease is an uncommon histiocytic disorder presenting as bilateral cervical lymphadenopathy in children and young adults. Under the revised classification of histiocytic disorders, it is classified in the` R’ group of histiocytosis. Cutaneous Rosai -Dorfman disease is regarded as a separate entity which falls under the`C’ group of histiocytosis according to this classification system. We herein report a case of cervical lymphadenopathy who initially developed swelling in the right side of the neck and later developed in the left side of the neck. Patient underwent mantoux test which showed induration of 22mm which was significant. No other symptoms like cough with expectoration, loss of appetite was present.chest x ray was normal. Tuberculous Lymphadenitis was suspected. FNAC was done but confirmatory diagnosis was not obtained, so Excision biopsy was done. Finally, microscopic examination revealed marked emperipolesis with sheets of mature lymphocytes and plasma cells which is pathognomic cytoarchitecture of Rosai Dorfman disease. No evidence of granuloma/ RS cells/ atypia seen. Immunohistochemistry showed S -100 – strong positivity
Problems and possibilities in fine-tuning of the Cepheid P-L relationship
Factors contributing to the scatter around the ridge-line period-luminosity
relationship are listed, followed by a discussion how to eliminate the adverse
effects of these factors (mode of pulsation, crossing number, temperature
range, reddening, binarity, metallicity, non-linearity of the relationship,
blending), in order to reduce the dispersion of the P-L relationship.Comment: 7 pages, 8 figures; accepted for publication in Astrophysics & Space
Scienc
Surface Magnetization of Aperiodic Ising Systems: a Comparative Study of the Bond and Site Problems
We investigate the influence of aperiodic perturbations on the critical
behaviour at a second order phase transition. The bond and site problems are
compared for layered systems and aperiodic sequences generated through
substitution. In the bond problem, the interactions between the layers are
distributed according to an aperiodic sequence whereas in the site problem, the
layers themselves follow the sequence. A relevance-irrelevance criterion
introduced by Luck for the bond problem is extended to discuss the site
problem. It involves a wandering exponent for pairs, which can be larger than
the one considered before in the bond problem. The surface magnetization of the
layered two-dimensional Ising model is obtained, in the extreme anisotropic
limit, for the period-doubling and Thue-Morse sequences.Comment: 19 pages, Plain TeX, IOP macros + epsf, 6 postscript figures, minor
correction
The AMBRE Project: Stellar parameterisation of the ESO:FEROS archived spectra
The AMBRE Project is a collaboration between the European Southern
Observatory (ESO) and the Observatoire de la Cote d'Azur (OCA) that has been
established in order to carry out the determination of stellar atmospheric
parameters for the archived spectra of four ESO spectrographs.
The analysis of the FEROS archived spectra for their stellar parameters
(effective temperatures, surface gravities, global metallicities, alpha element
to iron ratios and radial velocities) has been completed in the first phase of
the AMBRE Project. From the complete ESO:FEROS archive dataset that was
received, a total of 21551 scientific spectra have been identified, covering
the period 2005 to 2010. These spectra correspond to ~6285 stars.
The determination of the stellar parameters was carried out using the stellar
parameterisation algorithm, MATISSE (MATrix Inversion for Spectral SynthEsis),
which has been developed at OCA to be used in the analysis of large scale
spectroscopic studies in galactic archaeology. An analysis pipeline has been
constructed that integrates spectral reduction and radial velocity correction
procedures with MATISSE in order to automatically determine the stellar
parameters of the FEROS spectra.
Stellar atmospheric parameters (Teff, log g, [M/H] and [alpha/Fe]) were
determined for 6508 (30.2%) of the FEROS archived spectra (~3087 stars). Radial
velocities were determined for 11963 (56%) of the archived spectra. 2370 (11%)
spectra could not be analysed within the pipeline. 12673 spectra (58.8%) were
analysed in the pipeline but their parameters were discarded based on quality
criteria and error analysis determined within the automated process. The
majority of these rejected spectra were found to have broad spectral features
indicating that they may be hot and/or fast rotating stars, which are not
considered within the adopted reference synthetic spectra grid of FGKM stars.Comment: 28 pages, 28 figures, 9 table
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