Clinical Features, Dermoscopic Patterns and Histological Diagnostic Model for Melanocytic Tumors of Uncertain Malignant Potential (MELTUMP)

Cutaneous melanocytic lesions with atypical histological features can be difficult to categorize as benign or malignant. In the diagnosis of melanocytic lesions, the melanocytic tumor of uncertain malignant potential (MELTUMP) category has been widely used. Although one may favor a benign or malignant interpretation, a definitive diagnosis is not always possible, and long term clinical follow-up remains the only true evidence of biological behavior. We report 14 cases of MELTUMP with expert second opinion. Clinical pictures were available in 8 cases; dermoscopy was available in 5 cases. Accurate guidelines are delineated in the formulation of the diagnosis. We think that the histological diagnosis should be accompanied by a note in which the pathologist describes the histological pattern that has generated diagnostic uncertainty. Since the MELTUMP term does not exclude the malignant nature of the lesion, all microstaging attributes for melanoma should be added. Moreover, superficial atypical melanocytic proliferation of uncertain significance (SAMPUS) and MELTUMP categories should be included in the WHO classification of melanocytic tumors of the skin. The role of sentinel lymph node biopsy in MELTUMP has not yet been established. Recent studies have looked at concurrent tumor deposits in lymph nodes of MELTUMP, mostly of atypical Spitzoid lesions, and shown that these lesions rarely progress to overt malignancy. In our study, sentinel node metastasis was found in only one case. The follow-up period of this case and of the others has shown that the clinical outcome of MELTUMP tends to be favorable.</p

Clinical Features, Dermoscopic Patterns and Histological Diagnostic Model for Melanocytic Tumors of Uncertain Malignant Potential (MELTUMP)

Cutaneous melanocytic lesions with atypical histological features can be difficult to categorize as benign or malignant. In the diagnosis of melanocytic lesions, the melanocytic tumor of uncertain malignant potential (MELTUMP) category has been widely used. Although one may favor a benign or malignant interpretation, a definitive diagnosis is not always possible, and long term clinical follow-up remains the only true evidence of biological behavior. We report 14 cases of MELTUMP with expert second opinion. Clinical pictures were available in 8 cases; dermoscopy was available in 5 cases. Accurate guidelines are delineated in the formulation of the diagnosis. We think that the histological diagnosis should be accompanied by a note in which the pathologist describes the histological pattern that has generated diagnostic uncertainty. Since the MELTUMP term does not exclude the malignant nature of the lesion, all microstaging attributes for melanoma should be added. Moreover, superficial atypical melanocytic proliferation of uncertain significance (SAMPUS) and MELTUMP categories should be included in the WHO classification of melanocytic tumors of the skin. The role of sentinel lymph node biopsy in MELTUMP has not yet been established. Recent studies have looked at concurrent tumor deposits in lymph nodes of MELTUMP, mostly of atypical Spitzoid lesions, and shown that these lesions rarely progress to overt malignancy. In our study, sentinel node metastasis was found in only one case. The follow-up period of this case and of the others has shown that the clinical outcome of MELTUMP tends to be favorable.</p

A novel technique for very accurate three-dimensional monitoring of structural vibrations and displacement by remote radar sensors

The possibility of remotely sensing vibrations and displacements of industrial and civil infrastructures by exploiting electro-magnetic energy, has received new interest in the last years. In fact, preliminary experiments demonstrate that such a technique, not yet being fully investigated, is quite promising and could provide very accurate results with respect to the system currently being used (e.g. accelerometers). In fact, a radar sensor is able to provide a very accurate estimation of the Line of Sight displacements by continuously monitoring the distance between targets lying on the structures, and radar itself. This paper provides an insight into the potentialities of such a technique for accurate three-dimensional monitoring of structural vibrations and displacements

Instrumentation for gate current noise measurements on sub-100 nm MOS transistors

This work describes a measuring system that was developed to characterize the gate current noise performances of CMOS devices with minimum feature size in the 100 nm span. These devices play an essential role in the design of present day mixed signal integrated circuits, because of the advantages associated with the scaling process. The reduction in the gate oxide thickness brought about by CMOS technology downscaling leads to a non-negligible gate current due to direct tunneling phenomena; this current represents a noise source which requires an accurate characterization for optimum analog design. In this paper, two instruments able to perform measurements in two different ranges of gate current values will be discussed. Some of the results of gate current noise characterization will also be presented

Review of radiation effects leading to noise performance degradation in 100-nm scale microelectronic technologies

Advanced CMOS technologies promise to meet the demanding requirements of mixed-signal integrated circuits for detector readout in future experiments at SLHC, ILC and Super B Factory. In the particle physics community, microelectronics designers are presently evaluating CMOS processes with a minimum feature size in the 100 nm range. One of the key issues is noise performance and its degradation with exposure to high doses of ionizing radiation, as it is expected in the innermost detector layers of SLHC. This paper presents a comprehensive analysis of total dose damage mechanisms in 90 nm and 130 nm CMOS transistors and of their impact on the noise behavior of analog blocks. Modeling of radiation effects in these devices is used to define rad-hard design criteria

Impact of gate-leakage current noise in sub-100 nm CMOS front-end electronics

In future High Energy Physics experiments, readout integrated circuits for charged particle tracking systems will be realized by means of CMOS devices belonging to fabrication processes whose minimum feature size is in the 100 nm span. In nanoscale technologies, the reduction of the gate oxide thickness introduces a non-negligible gate current due to direct tunneling phenomena. This leakage current, being caused by discrete charges randomly crossing a potential barrier, results in an increase of the static power consumption for digital circuits and might degrade noise performances in analog applications. As a consequence, in these advanced CMOS processes an accurate characterization of the gate current noise is mandatory in order to establish design criteria for detector front-ends. This work presents the results of static and noise characterization of the gate-leakage current carried out on NMOS devices belonging to a 90 nm commercial process. Data extracted from the measurements have been used to evaluate the impact of this noise source on the resolution limits achievable for low-noise charge sensitive amplifiers within this technology node

CMOS technologies in the 100 nm range for rad-hard front-end electronics in future collider experiments

130 nm and 90 nm CMOS processes are going to be used in the design of mixed-signal integrated circuits for the readout of detectors in the future generation of HEP experiments. In applications such as inner SLHC detectors, these ultra-deep submicron systems will have to stand total doses of ionizing radiation of the order of 100 Mrad and beyond. While the scaling of the gate oxide thickness to about 2 nm gives a high degree of radiation tolerance, issues such as the gate tunneling current and the sidewall leakage associated to lateral isolation oxides must be investigated. This paper provides an analysis of an extensive set of irradiation tests carried out on 130 nm and 90 nm CMOS transistors belonging to commercial technologies. With special focus on the design of analog front-end circuits for silicon pixel and strip detectors, the impact of ionizing radiation on the noise performance is evaluated and the underlying physical degradation mechanisms are pointed out to provide criteria for improving radiation hardness properties

Noise behavior of a 180 nm CMOS SOI technology for detector front-end electronics

This paper is motivated by the growing interest of the detector and readout electronics community towards silicon-on-insulator CMOS processes. Advanced SOI MOSFETs feature peculiar electrical characteristics impacting their performance with respect to bulk CMOS devices. Here we mainly focus on the study of these effects on the noise parameters of the transistors, using experimental data relevant to 180 nm fully depleted SOI devices as a reference. The comparison in terms of white and 1/f noise components with bulk MOSFETs with the same minimum feature size gives a basis of estimate for the signal-to-noise ratio achievable in detector front-end integrated circuits designed in an SOI technology

Perspectives for low noise detector readout in a sub-quarter-micron CMOS SOI technology

This paper is motivated by the growing interest of the detector and readout electronics community towards silicon-on-insulator CMOS processes. Advanced SOI MOSFETs feature peculiar electrical characteristics impacting their performance with respect to bulk CMOS devices. Here we mainly focus on the study of these effects on the noise parameters of the transistors, using experimental data relevant to 180 nm fully depleted SOI devices as a reference. The comparison in terms of white and 1/f noise components with bulk MOSFETs with the same minimum feature size gives a basis of estimate for the signal-to-noise ratio achievable in detector front-end integrated circuits designed in an SOI technology