The impact of frozen sections on final surgical margins in squamous cell carcinoma of the oral cavity and lips: a retrospective analysis over an 11 years period

Taking intraoperative frozen sections (FS) is a widely used procedure in oncologic surgery. However so far no evidence of an association of FS analysis and premalignant changes in the surgical margin exists. Therefore, the aim of this study was to evaluate the impact of FS on different categories of the final margins of squamous cell carcinoma (SCC) of the oral cavity and lips.

The examination and identification of bite marks in foods using 3D scanning and 3D comparison methods

Bite mark analysis offers the opportunity to identify the biter based on the individual characteristics of the dentitions. Normally, the main focus is on analysing bite mark injuries on human bodies, but also, bite marks in food may play an important role in the forensic investigation of a crime. This study presents a comparison of simulated bite marks in different kinds of food with the dentitions of the presumed biter. Bite marks were produced by six adults in slices of buttered bread, apples, different kinds of Swiss chocolate and Swiss cheese. The time-lapse influence of the bite mark in food, under room temperature conditions, was also examined. For the documentation of the bite marks and the dentitions of the biters, 3D optical surface scanning technology was used. The comparison was performed using two different software packages: the ATOS modelling and analysing software and the 3D studio max animation software. The ATOS software enables an automatic computation of the deviation between the two meshes. In the present study, the bite marks and the dentitions were compared, as well as the meshes of each bite mark which were recorded in the different stages of time lapse. In the 3D studio max software, the act of biting was animated to compare the dentitions with the bite mark. The examined food recorded the individual characteristics of the dentitions very well. In all cases, the biter could be identified, and the dentitions of the other presumed biters could be excluded. The influence of the time lapse on the food depends on the kind of food and is shown on the diagrams. However, the identification of the biter could still be performed after a period of time, based on the recorded individual characteristics of the dentitions.

Tissue banking in a regional hospital: a promising future concept? First report on fresh frozen tissue banking in a hospital without an integrated institute of pathology

Vital tissue provided by fresh frozen tissue banking is often required for genetic tumor profiling and tailored therapies. However, the potential patient benefits of fresh frozen tissue banking are currently limited to university hospitals. The objective of the present pilot study--the first one in the literature--was to evaluate whether fresh frozen tissue banking is feasible in a regional hospital without an integrated institute of pathology.

Is there an indication for frozen section examination of the ureteral margins during cystectomy for transitional cell carcinoma of the bladder?

PURPOSE: We evaluated the incidence of pathological findings of the ureter at cystectomy for transitional cell carcinoma of the bladder and assessed the usefulness of intraoperative frozen section examination of the ureter. MATERIALS AND METHODS: Histopathological findings of ureteral frozen section examination were compared to the corresponding permanent sections and the diagnostic accuracy of frozen section examination was evaluated. These segments were then compared to the more proximal ureteral segments resected at the level where they cross over the common iliac arteries. The histopathological findings of the ureteral segments were then correlated for upper urinary tract recurrence and overall survival. RESULTS: Transitional cell carcinoma or carcinoma in situ was found on frozen section examination of the distal ureter in 39 of 805 patients (4.8%) and on permanent sections in 29 (3.6%). In 755 patients the false-negative rate of frozen section examination of the ureters was 0.8%. Of the patients with carcinoma in situ diagnosed on the first frozen section examination 80% also had carcinoma in situ in the bladder. Transitional cell carcinoma or carcinoma in situ in the most proximally resected ureteral segments was found in 1.2% of patients. After radical cystectomy there was tumor recurrence in the upper urinary tract in 3% of patients with negative ureteral frozen section examination and in 17% with carcinoma in situ on frozen section examination. CONCLUSIONS: Routine frozen section examination of the ureters at radical cystectomy is only recommended for patients with carcinoma in situ of the bladder, provided the ureters are resected where they cross the common iliac arteries.

Relative sensitivity factors of inorganic cations in frozen-hydrated standards in secondary ion MS analysis

We describe the measurement, at 100 K, of the SIMS relative sensitivity factors (RSFs) of the main physiological cations Na+, K+, Mg2+, and Ca2+ in frozen-hydrated (F-H) ionic solutions. Freezing was performed by either plunge freezing or high-pressure freezing. We also report the measurement of the RSFs in flax fibers, which are a model for ions in the plant cell wall, and in F-H ionic samples, which are a model for ions in the vacuole. RSFs were determined under bombardment with neutral oxygen (FAB) for both the fibers and the F-H samples. We show that referencing to ice-characteristic secondary ions is of little value in determining RSFs and that referencing to K is preferable. The RSFs of Na relative to K and of Ca relative to Mg in F-H samples are similar to their respective values in fiber samples, whereas the RSFs of both Ca and Mg relative to K are lower in fibers than in F-H samples. Our data show that the physical factors important for the determination of the RSFs are not the same in F-H samples and in homogeneous matrixes. Our data show that it is possible to perform a SIMS relative quantification of the cations in frozen-hydrated samples with an accuracy on the order of 15%. Referencing to K permits the quantification of the ionic ratios, even when the absolute concentration of the referencing ion is unknown. This is essential for physiological studies of F-H biological samples.

The frozen elephant trunk: an interesting hybrid endovascular-surgical technique to treat complex pathologies of the thoracic aorta

The treatment of complex aortic pathologies involving the ascending aorta, the aortic arch, and the descending aorta remains a challenging issue in aortic surgery. The frozen elephant trunk procedure effectively combines surgical and interventional technologies in the treatment of extensive aortic aneurysms and dissections. We present two patients with complex aortic lesions involving all three segments of the thoracic aorta. The device used in our series is the new E-vita open hybrid prosthesis consisting of a proximal woven polyester tube and a distal self-expandable nitinol stent graft, which can be delivered antegrade into the descending aorta.

Parotid tumors: fine-needle aspiration and/or frozen section

OBJECTIVE: The purpose of this study was to analyze and compare the value of fine-needle aspiration cytology (FNAC) and frozen section (FS) analysis in the assessment of parotid gland tumors. STUDY DESIGN: Chart review and cross-sectional analysis. SUBJECTS AND METHODS: FNAC and FS analysis of 110 parotid tumors, 68 malignancies and 42 benign tumors, were analyzed and compared with the final histopathologic diagnosis. RESULTS: The accuracy, sensitivity, and specificity of FNAC in detecting malignant tumors were 79 percent, 74 percent, and 88 percent, respectively. On FS analysis, the accuracy, sensitivity, and specificity in detecting malignant tumors were 94 percent, 93 percent, and 95 percent, respectively. The histologic tumor type was correctly diagnosed by FNAC and FS in 27 of 42 (64%) and 39 of 42 (93%) benign tumors, respectively, and in 24 of 68 (35%) and 49 of 68 (72%) malignant neoplasms, respectively. CONCLUSION: The current analysis showed a superiority of FS compared with FNAC regarding the diagnosis of malignancy and tumor typing. FNAC alone is not prone to determine the surgical management of parotid malignancies.

Electron microscopy of high pressure frozen samples: bridging the gap between cellular ultrastructure and atomic resolution

Transmission electron microscopy has provided most of what is known about the ultrastructural organization of tissues, cells, and organelles. Due to tremendous advances in crystallography and magnetic resonance imaging, almost any protein can now be modeled at atomic resolution. To fully understand the workings of biological "nanomachines" it is necessary to obtain images of intact macromolecular assemblies in situ. Although the resolution power of electron microscopes is on the atomic scale, in biological samples artifacts introduced by aldehyde fixation, dehydration and staining, but also section thickness reduces it to some nanometers. Cryofixation by high pressure freezing circumvents many of the artifacts since it allows vitrifying biological samples of about 200 mum in thickness and immobilizes complex macromolecular assemblies in their native state in situ. To exploit the perfect structural preservation of frozen hydrated sections, sophisticated instruments are needed, e.g., high voltage electron microscopes equipped with precise goniometers that work at low temperature and digital cameras of high sensitivity and pixel number. With them, it is possible to generate high resolution tomograms, i.e., 3D views of subcellular structures. This review describes theory and applications of the high pressure cryofixation methodology and compares its results with those of conventional procedures. Moreover, recent findings will be discussed showing that molecular models of proteins can be fitted into depicted organellar ultrastructure of images of frozen hydrated sections. High pressure freezing of tissue is the base which may lead to precise models of macromolecular assemblies in situ, and thus to a better understanding of the function of complex cellular structures.