Histomorphologic correlation with routine histology and optical coherence tomography

BACKGROUND

Optical coherence tomography (OCT) is a new and promising diagnostic technique for investigation of skin tumours. We describe a method that makes evaluation and definition of specific morphologic structures of skin tumours via OCT more accurate.

MATERIALS AND METHOD

We investigated three patients with basal cell carcinoma and three patients with melanocytic nevi. Three-dimensional (3D) images were obtained from these skin tumours via OCT according to previously applied marks, which were tattooed with special histological marking dye after excision of the tumours. Corresponding to these marks, we investigated serial histological sections (haematoxylin&eosin staining).

RESULTS

We could prove similar morphological structures both in OCT and histology. Due to tissue deformation, the compared measurements of structures like cell nests or epidermal thickness were slightly deviated. However, by this method we could prove similar tissue formations in OCT and histology.

CONCLUSIONS

Due to the deformation by histological processing and slightly different sectioning levels, the comparison of histological pictures and OCT images seems difficult. Nevertheless, in two cases it was possible to demonstrate the same morphological structures with OCT imaging and histological investigation. Our method could play an important role for further evaluation of OCT images. We estimate better evaluation of OCT imaging using a 3D reconstruction method.

Nichtinvasive Diagnostik von Hautfunktionen

Noninvasive investigation of skin functions is increasingly employed in dermatology and cosmetology. It enables one to study aspects of skin functions that cannot always be appreciated by sensory perception. Noninvasive methods permit objective and reproducible investigation of distinct biophysical parameters. In the age of evidence-based medicine this becomes more and more important. Biophysical data can be quantified, analyzed, and stored electronically. In an overview, selected noninvasive techniques of skin function testing are introduced and their relevance in dermatology, dermatopharmacology, and cosmetology is discussed.

Diagnostic and neural analysis of skin cancer (DANAOS). A multicentre study for collection and computer-aided analysis of data from pigmented skin lesions using digital dermoscopy

BACKGROUND

Early detection of melanomas by means of diverse screening campaigns is an important step towards a reduction in mortality. Computer-aided analysis of digital images obtained by dermoscopy has been reported to be an accurate, practical and time-saving tool for the evaluation of pigmented skin lesions (PSLs). A prototype for the computer-aided diagnosis of PSLs using artificial neural networks (NNs) has recently been developed: diagnostic and neural analysis of skin cancer (DANAOS).

OBJECTIVES

To demonstrate the accuracy of PSL diagnosis by the DANAOS expert system, a multicentre study on a diverse multinational population was conducted.

METHODS

A calibrated camera system was developed and used to collect images of PSLs in a multicentre study in 13 dermatology centres in nine European countries. The dataset was used to train an NN expert system for the computer-aided diagnosis of melanoma. We analysed different aspects of the data collection and its influence on the performance of the expert system. The NN expert system was trained with a dataset of 2218 dermoscopic images of PSLs.

RESULTS

The resulting expert system showed a performance similar to that of dermatologists as published in the literature. The performance depended on the size and quality of the database and its selection.

CONCLUSIONS

The need for a large database, the usefulness of multicentre data collection, as well as the benefit of a representative collection of cases from clinical practice, were demonstrated in this trial. Images that were difficult to classify using the NN expert system were not identical to those found difficult to classify by clinicians. We suggest therefore that the combination of clinician and computer may potentially increase the accuracy of PSL diagnosis. This may result in improved detection of melanoma and a reduction in unnecessary excisions.

Caffeine-induced anxiety and increase of kynurenine concentration in plasma of healthy subjects: a pilot study

The concentration of kynurenine, a neuroactive tryptophan metabolite, in blood plasma after pharmacologically induced anxiety was studied. Anxiety was provoked in 15 healthy volunteers by an anxiogenic dose of caffeine. Kynurenine concentration was markedly increased at the peak of anxiety and returned to normal after anxiety had abated. Possible causes responsible for this effect are discussed. There is a correlation between kynurenine concentration in blood plasma and indices of state and trait anxiety (Spielberger-Khanin scale) and anxiety (Hamilton scale) at baseline. The correlation disappears at the peak of anxiety. It is suggested that kynurenine is involved in caffeine-induced anxiety in humans. The absence of correlation at the peak of caffeine-induced anxiety is discussed.