Ultrasound in dermatology. Part II. Ultrasound of regional lymph node basins and subcutaneous tumours

Ultrasound in dermatology is a non-invasive tool for the detection and verification of tumours in skin, subcutaneous tissues and in lymph node basins. Since the introduction of ultrasound examination in the routine practice of dermatology in the late seventies [1], ultrasound has evolved to become a standard diagnostic method, at least in Europe. Subcutaneous or regional nodal metastases or benign tumours or tissue accumulation may not be palpable due to small size, distance from the skin surface or location in an area of postoperative or radiation fibrosis, which renders a physical examination on its own difficult. Palpation even by an experienced physician is also known to be an inaccurate technique for the assessment of lesions in head and neck cancer [2] as well as in scar tissue. Ultrasound, on the contrary is able to give additional and reliable information about the exact position of a tumour, surrounding anatomical structures, the dimension of the lesion in two perpendicular diameters in mm, its echo pattern as well as the distance from the skin surface. High resolution ultrasound technique is not only able to detect small targets (< 3 mm), but also to predict difficulties in the surgical search for metastases due to a deep subcutaneous or intramuscular position, or a localization near structures (e.g. vessels) which could easily be traumatized. Several invasive and non-invasive staging tools have been developed for the detection of regional disease or tumours in the soft tissue to support the often ineffective physical examination on its own. Among these techniques, ultrasound has been proven to have superior sensitivity to physical examination in the detection of regional metastases in melanoma patients [3-6] as well as in hematology and oncology patients [7] and it even facilitates the surgical management of such patients [8-10]. Based on technical equipment and clinical requirements, ultrasound used in dermatology is performed using frequencies between 7.5 and 15 MHz. Additionally duplex and colour flow analysis may complement grey-scale ultrasound by demonstrating tumour vascularity and characterising masses [11, 12]. In this part of the two CME articles on ultrasound we want to illustrate the most important technical details, procedural steps and the clinical use of high-frequency ultrasound in dermatology.

Ultrasound in dermatology. Part I. High frequency ultrasound

This paper addresses the basic terminology of modern ultrasound equipment for the examination of the skin, the technical limitations of currently available equipment and the normal skin structure. Different applications for dermatosonography are discussed, and the paper summarises current knowledge about common sources of variation in the ultrasound image of the skin, such as skin tumours and selected skin diseases.

Morton's intermetatarsal neuroma: morphology and histological substrate

Twenty-three biopsies from patients with the typical symptoms of intermetatarsal neuroma (so-called Morton's metatarsalgia) were compared histologically and semi-quantitatively with 25 plantar nerves from the intermetatarsal space III/IV gained at autopsies from cases where no problems in the forefoot had been recorded. The histomorphological examination of the nerves from autopsies revealed the same findings as were found in the biopsies. Thus, qualitatively, the nerves from patients could not be distinguished from those gained at autopsy. The only difference was the diameter of the resected nerves: semi-quantitative analysis of the nerves showed that the 17 thinnest ones were all from autopsies and the five thickest ones from biopsies of symptomatic patients. At medium diameters, however, there was wide overlap of the two groups. The study yielded a specificity of the swelling of 80 % and a sensitivity of 78%. From these results it must be concluded that diagnostic MRIs or ultrasonography, are unnecessary for decision-making about operative treatment and are not superior to exploratory local anaesthesia. Since histomorphological findings in intermetatarsal neuroma (so far accepted as the gold standard for confirmation of that diagnosis) were the same as findings in autopsied (normal) specimens, the value of postoperative histological examination is questioned. It merely proved that the nerve has been resected.

[Preoperative sonographic diagnosis of melanoma--comparison of 7.5- and 20-MHz sonography]

AIM

High-frequency sonography has become extremely helpful for the preoperative assessment of malignant melanoma. The purpose of this study was to compare the preoperative vertical tumour thickness as assessed by 7.5 MHz as well as 20 MHz ultrasound probes to the postoperative tumour thickness as determined histomorphometrically.

METHODS

249 patients with malignant melanoma were studied using a conventional 7.5 MHz ultrasound machine (since 1987) or a high-frequency 20 MHz ultrasound imaging system (since 1991).

RESULTS

The correspondence of the sonographically assessed tumour thickness with the thickness assessed by histomorphometry was significantly better for high-frequency sonography (r = 0.94) as compared to conventional sonography (r = 0.76). For stages pT3 and pT4, however, this difference was not significant.

CONCLUSION

Based on these data, high-frequency sonography should be given preference in the preoperative assessment of malignant melanoma over conventional 7.5 MHz ultrasound. However, for stages pT3 and pT4 both methods offer similarly reliable results.

Management of cerebral metastases from malignant melanoma: results of a combined, simultaneous treatment with fotemustine and irradiation

We report results of a conservative treatment for brain metastases from malignant melanoma with a combination of irradiation and chemotherapy (fotemustine and/or DTIC). To date, 12 patients have been treated. There was a complete remission of the brain metastases in four patients. In two patients a partial remission was observed. The mean survival of the responder was 8.2 months (95% confidence interval 3.8-12.6 months). The most common side effects were thrombocytopenia, leukopenia, and alopecia. Altogether, the treatment was well tolerated. As the outcome of patients with brain metastases from malignant melanoma is generally poor, this combined chemo- and radiation therapy may provide improved care for such patients.

Structural heterogeneity of the sialic-acid-containing oligosaccharides from the lipopolysaccharide of Hafnia alvei strain 2 as detected by FABMS studies

The structure of four oligosaccharide fractions from the Hafnia alvei strain 2 lipopolysaccharide (LPS) have been assigned by FABMS. This approach corroborates data previously established by NMR spectroscopy for the major oligosaccharides in these fractions [A. Gamian, E. Romanowska, U. Dabrowski, J. Dabrowski, Biochemistry 30 (1991) 5032-5038; E. Katzenellenbogen, A. Gamian, E. Romanowska, U. Dabrowski, J. Dabrowski, Biochem. Biophys. Res. Commun. 194 (1993) 1058-1064; N. Ravenscroft, A. Gamian, E. Romanowska, Eur. J. Biochem. 227 (1995) 889-896]. In addition, the MS/MS with B/E linked scan technique allowed the detection of an additional oligosaccharide with the structure: [formula: see text] lacking the branched O-6 linked glucopyranose residue at the 3-linked Gal unit, which indicates a structural heterogeneity for the major oligosaccharide fraction.

Does smoking protect from Alzheimer's disease? Alzheimer-type changes in 301 unselected brains from patients with known smoking history

The objective of this report is to investigate whether smoking exerts any influence on the number of senile plaques and Alzheimer neurofibrillary tangles. A retrospective study was based on unselected consecutive autopsy findings on the brains of 301 patients aged 65 years or older examined at the Institute of Pathology, Basel. Brains were investigated according to a fixed protocol. Histological examination was performed on 15 paraffin-embedded tissue blocks per brain using staining with silver impregnation specific for Alzheimer neurofibrillary tangles and for senile plaques, and Alzheimer-type changes were quantified. Retrospective assessment of smoking history was also based on a fixed protocol. Statistical analysis of the relationship between the smoking habits and the amount of Alzheimer-type changes was performed and included analysis of 72 age- and sex-matched smoker-nonsmoker pairs from within the total of 301 cases to compensate for variations in these changes due to age/sex alone. The influence of smoking on the total of 301 cases cannot be proven statistically. But a protective action against senile plaque formation could be demonstrated in 28 age matched pairs of smoking-nonsmoking women. Furthermore a positive correlation between the amount of smoking and the neurofibrillary changes as expressed in Braak stages in smokers of both sexes was present. Thus, there seems to be an influence of nicotine on the structural alterations of Alzheimer's disease which can exert itself in opposite directions.

Argyrophilic grain disease: widespread hyperphosphorylation of tau protein in limbic neurons

Argyrophilic grains (ArG) and coiled bodies of argyrophilic grain disease (AgD) and the neurofibrillary lesions of Alzheimer's disease (AD) share similar antigenic determinants, among them hyperphosphorylated microtubule-associated protein tau. Nothing is known about the mechanisms underlying tau hyperphosphorylation in AgD, the hyperphosphorylated sites or the intracellular distribution of abnormally phosphorylated tau. We have analysed brain tissue sections from 41 subjects with AgD with a panel of phosphorylation-dependent (AT270, AT8, Tau-1, AT180, 12E8, PHF-1 and AT100) and phosphorylation-independent anti-tau antibodies (N-tau 5, 304, 189 and 134). All antibodies labelled ArG, coiled bodies and neurofibrillary lesions, with the exception of antibody 12E8, which stained a subset of neurofibrillary tangles, but no ArG or coiled bodies. Most pyramidal neurons in areas rich in ArG showed diffuse granular tau labelling in cell bodies and dendrites. Only very few tau-positive cells also contained neurofibrillary tangles. Phosphorylation-dependent anti-tau antibodies also stained a felt-like network of Gallyas-negative filiform neurites in layer CA1 of the hippocampus and in layer pre-B of the transentorhinal cortex. These results demonstrate a widespread hyperphosphorylation of tau protein in the somatodendritic domain of neurons in AgD, in addition to silver grains in the neuropil. Unlike in AD, tau hyperphosphorylation in the somatodendritic domain in AgD does not appear to be followed by neurofibrillary tangle formation, even in the presence of widespread ArG in the neuropil. Furthermore, our data suggest that no strict correlation exists between the presence or density of ArG in the limbic area and the occurrence of dementia.

Structural studies of the major glycolipid from Saccharopolyspora genus

A major glycolipid was isolated from the well characterized Saccharopolyspora species, S. hirsuta, S. rectivirgula, S. erythraea and one not completely identified strain (Saccharopolyspora sp.). On the basis of sugar and methylation analysis, specific enzymatic and chemical degradations of the carbohydrate moiety, its FAB mass spectrometry and NMR spectroscopy characterizations, the carbohydrate part was shown to be the glycerol linked dimannoside alpha-D-Manp-(1-->3)-alpha-D-Manp-(1-->1/3)Gro. The internal mannose residue is esterified at C-6 by one fatty acid residue, whereas another fatty acyl chain substitutes the primary methylene position of glycerol. The main fatty acyl residues are anteiso-branched heptadecanoic acid and the iso-branched fatty acids iso-17:0, iso-16:0, and iso-18:0, with the former species being predominant. The major glycolipid has potential value for taxonomic and diagnostic purposes, especially in the specific diagnosis of farmer's lung disease.

Subependymoma of the third ventricle after partial resection of a craniopharyngioma and repeated postoperative irradiation

We present the case of a 28-year-old man who underwent craniotomy and subsequent radiotherapy for a suprasellar craniopharyngioma at the age of 8 years. The patient suffered from a severe pituitary deficiency until his death. The cause of death was a bronchopneumonia. At necropsy epithelial tissue characteristic of craniopharyngioma was no longer found, but instead a subependymoma of the third ventricle. Up to now most reported primary central nervous system tumors associated with subependymomas were ependymomas. However, in 1 case very similar to ours a subependymoma was associated with a craniopharyngioma. Furthermore, only rare examples of subependymomas of the third ventricle have been reported. The growth of a subependymoma might have been induced by intense reactive gliosis as a response of the adjacent brain tissue to the craniopharyngioma. However, in view of the repeated post-operative irradiation in our case the possibility of radiation-induced glioma has also to be considered.