1/24. Basaloid squamous cell carcinoma of oral cavity and oropharynx.Basaloid squamous cell carcinoma is a variant of squamous cell carcinoma with distinctive histological and immunohistochemical characteristics and aggressive behaviour involving predominantly the upper aerodigestive tract. We describe the clinicopathological findings, along with immunohistochemical investigations, in 5 new cases with carcinoma localized in oral cavity and oropharynx.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
2/24. Pseudovascular squamous cell carcinoma of the skin.The presence of acantholysis in squamous cell carcinomas (SCC) may rarely be so extreme that, histologically, it mimics a vascular tumour. However, careful histological examination and immunohistochemical study usually lead to the correct diagnosis. We describe such a case to highlight the clinico-pathological features of this rare form of cutaneous malignancy and to emphasize the difficulties in establishing the correct diagnosis. We also review similar cases reported in the literature. Pseudovascular SCC shows a higher degree of recurrence and metastasis than other variants of SCC. Acantholytic foci in these tumours may demonstrate changes in keratinocyte differentiation markers, and this may explain the more aggresive biological behaviour in the pseudovascular variant of SCC.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
3/24. Primary squamous cell carcinoma of the thyroid gland: an entity with aggressive clinical behaviour and distinctive cytokeratin expression profiles.AIMS: Primary squamous cell carcinoma of the thyroid gland is uncommon. This study aims to identify the clinicopathological features and the pattern of expression of cytokeratins and oncoproteins in this tumour. methods AND RESULTS: Histological slides from Chinese patients with thyroid cancer treated in our institution from 1980 to 1999 were reviewed. patients with primary squamous cell carcinoma of the thyroid were identified and their clinical records were analysed. The expression of cytokeratins (CKs), p53 and p21 in these cases were also studied by an immunohistochemical method. Four women (mean age 71 years) with squamous cell carcinoma of thyroid were found. The main presenting features were signs and symptoms of airway obstruction in three patients and neck swelling in one. The tumours were located at the right lobe (n=2), left lobe (n=1) or in both lobes of the thyroid (n=1). One patient died shortly after admission and the other three died within 4 months after thyroidectomy. The p53 protein was positive in 50% (2/4) of the tumours and p53 tumours were poorly differentiated. The tumours were negative for p21. CK19 was expressed in all the tumours while CK7 expression was noted in 3/4 of the tumours. One carcinoma showed focal positivity to CK18. The tumours were negative for CKs 1, 4, 6, 10/13 and 20. The pattern of cytokeratin expression in squamous cell carcinoma of the thyroid gland was different from carcinoma showing thymus-like differentiation (CASTLE) of the thyroid gland and oesophageal squamous cell carcinoma. CONCLUSIONS: Squamous cell carcinoma of the thyroid has aggressive clinical behaviour and characteristic CK expression pattern. p53 over-expression in these tumours was associated with tumour differentiation.- - - - - - - - - - ranking = 5keywords = behaviour (Clic here for more details about this article) |
4/24. Lymphoepithelioma-like carcinoma of oral cavity: report of three cases and literature review.Lymphoepithelioma-like carcinoma is a rare tumour in the oral cavity and is characterized histologically by non-keratinizing, undifferentiated squamous cell carcinoma with lymphocytic infiltration. Three consecutive cases of intraoral lymphoepithelioma-like carcinoma are reported. A review of the literature reveals a similar biological behaviour to that of nasopharyngeal lymphoepithelioma: a high incidence of cervical nodal spread and remarkable radiosensitivity. Chemotherapy should be considered when nodal or distant metastases are present. The association of the Epstein-Barr virus with this tumour remains unclear but our experience suggests a positive correlation in Chinese individuals.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
5/24. Accuracy of fine-needle aspiration biopsy for Warthin's tumours.BACKGROUND: Although the overall accuracy of fine-needle aspiration biopsy (FNAB) for salivary gland neoplasms has been well established, definitive results for Warthin's tumour (WT) are lacking. For most salivary gland tumours, surgery is recommended because of progressive enlargement and the risk of malignant transformation. This behaviour is unusual with WT, and surgery is usually advocated for pathologic confirmation. A highly accurate diagnosis of WT by FNAB may justify conservative management for the asymptomatic patient. However, if the reliability of this diagnostic procedure is questionable, there should be little hesitation in recommending parotidectomy. methods: A retrospective study design was used to evaluate the accuracy of FNAB for parotid WTs. All consecutive parotid FNABs and parotidectomy specimens from 1992 to 2000 were reviewed, and cases suggestive of WT were identified. The fine-needle cytology and histopathology results were then correlated. The true-positive, false-positive, and false-negative rates were tabulated to determine the sensitivity and positive predictive value (PPV) of FNAB for WT. RESULTS: A total of 41 patients were included in the study. Of these, 33 patients had FNABs suggestive or diagnostic of WT that were confirmed following parotidectomy (true positives = 33). In 4 patients, the FNAB incorrectly suggested WT, with the surgical histopathology confirming different diagnoses (false positives = 4) (3 acinic cell carcinomas and 1 pleomorphic adenoma). Four patients had surgically confirmed WTs with FNABs suggestive of other diagnoses (false negatives = 4) (1 cystic squamous cell carcinoma, 1 simple cyst, 1 "inflammatory process," and 1 "negative for malignant cells"). The sensitivity and PPV were 89.2% and 89.2%, respectively. CONCLUSION: Although the sensitivity and PPV in this study are high, the false-positive rate is clinically significant given the type of lesions missed. Three acinic cell carcinomas and one pleomorphic adenoma were misdiagnosed as WT on FNAB. One must be cautious in recommending conservative management for parotid tumours even when a WT is suggested by FNAB.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
6/24. Absence of multiple local minima effects in intensity modulated optimization with dose-volume constraints.This paper reports on the analysis of intensity modulated radiation treatment optimization problems in the presence of non-convex feasible parameter spaces caused by the specification of dose-volume constraints for the organs-at-risk (OARs). The main aim was to determine whether the presence of those non-convex spaces affects the optimization of clinical cases in any significant way. This was done in two phases: (1) Using a carefully designed two-dimensional mathematical phantom that exhibits two controllable minima and with randomly initialized beamlet weights, we developed a methodology for exploring the nature of the convergence characteristics of quadratic cost function optimizations (deterministic or stochastic). The methodology is based on observing the statistical behaviour of the residual cost at the end of optimizations in which the stopping criterion is progressively more demanding and carrying out those optimizations to very small error changes per iteration. (2) Seven clinical cases were then analysed with dose-volume constraints that are stronger than originally used in the clinic. The clinical cases are two prostate cases differently posed, a meningioma case, two head-and-neck cases, a spleen case and a spine case. Of the 14 different sets of optimizations (with and without the specification of maximum doses allowed for the OARs), 12 fail to show any effect due to the existence of non-convex feasible spaces. The remaining two sets of optimizations show evidence of multiple minima in the solutions, but those minima are very close to each other in cost and the resulting treatment plans are practically identical, as measured by the quality of the dose-volume histograms (DVHs). We discuss the differences between fluence maps resulting from those similar treatment plans. We provide a possible reason for the observed results and conclude that, although the study is necessarily limited, the annealing characteristics of a simulated annealing method may not be justified in clinical optimization in the presence of dose-volume constraints. The results of optimizations by the Newton gradient (NG) method with a quadratic cost function are reported in detail. An adaptive simulated annealing method, optimizing the same function, and the dynamically penalized likelihood method, optimizing a log likelihood function, have also been used in the study. The results of the latter two methods have only been discussed briefly, as they yielded the same conclusions as the NG method.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
7/24. Primary squamous cell carcinoma of the breast.A patient with pure primary squamous cell carcinoma (SCC) of the breast is reported. The patient was a 72 year old female who presented with a 4 month history of an enlarging left breast mass. Surgery involved a radical mastectomy and this was followed by post-operative radiotherapy and chemotherapy. The patient died of extensive metastatic disease some four months after surgery. The various characteristics of SCC of the breast are briefly discussed. A sub-group of SCC of the breast is identified among reported cases in which the clinical course is characterised by a very rapid growth, extremely aggressive behaviour and early metastasis.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
8/24. Basaloid squamous cell carcinoma report of a case and review of literature.Basaloid squamous cell carcinoma (BSCC) is an aggressive distinct variant of squamous cell carcinoma that mandates recognition as a separate entity owing to the difference in its clinical behaviour. Histologically this tumor can mimic other neoplasms like adenoid cystic carcinoma, neuroendocrine carcinoma and basal cell adenocarcinoma. BSCC occurs most commonly in older men and has a site predilection for the upper aero-digestive tract. We report a case of basaloid squamous cell carcinoma for its relative rarity, which was diagnosed in a 52 year old woman, with a brief review of literature.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
9/24. Squamous cell carcinoma of the rectum: a case report and review of the literature.Squamous cell carcinoma of the colon and rectum are extremely rare neoplasms. Many questions regarding their histogenesis and biological behaviour remain unanswered. Surgery is the most effective therapy, and adjuvant chemotherapy and radiotherapy should be considered, especially for node-positive patients. We present a patient with squamous cell carcinoma of the middle rectum who underwent abdominoperineal resection and postoperative adjuvant chemotherapy. The pertinent literature is reviewed.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
10/24. Scintigraphy for interpretation of malignant tumours of the head and neck: comparison of technetium-99m-hexakis-2-methoxyisobutylisonitrile (Tc-MIBI) and thallium-201-chloride (Tl-201).OBJECTIVES: The purpose of this study was to compare the usefulness of technetium-99m-hexakis-2-methoxyisobutylisonitrile (99Tc(m)-MIBI) and thallium-201-chloride (Tl-201) as scintigraphic agents. methods: Dynamic and static scintigraphic imaging with 99Tc(m)-MIBI and Tl-201 were performed on patients with a variety of malignant and benign tumours. Factors of the grade of the static scan, the blood flow index, the early and delayed retention indexes, and the tumour retention index were obtained from the scintigraphy. In addition to these factors, the grade of tissue differentiation and tumour size were evaluated to clarify the difference between 99Tc(m)-MIBI and Tl-201 for the diagnosis of malignant tumours of the head and neck. RESULTS: 99Tc(m)-MIBI accumulation depended upon the blood flow index in the early static scan, but this accumulation did not correlate with tumour size. The accumulation in most subjects decreased in the delayed static scan, and the tumour retention index had a tendency to decrease with the grade of tissue differentiation. Tl-201 accumulation depended upon the blood flow index in the early static scan similar to 99Tc(m)-MIBI, and the accumulation correlated with tumour size, unlike 99Tc(m)-MIBI. The tumour retention index had a tendency to increase with the grade of tissue differentiation. Thus, the tumour retention indexes showed opposite behaviours between 99Tc(m)-MIBI and Tl-201, but they both accurately determined tumour malignancy. CONCLUSIONS: There was no major difference between 99Tc(m)-MIBI and Tl-201scintigraphy with respect to accuracy of diagnosis of malignant tumours of the head and neck. However, 99Tc(m)-MIBI was superior to Tl-201 for small-size tumours and Tl-201 was useful for large-size tumours.- - - - - - - - - - ranking = 1keywords = behaviour (Clic here for more details about this article) |
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