Diagnostic accuracy of high-frequency ultrasound for cutaneous neoplasms: a narrative review of the literature

High-frequency ultrasound has been used to visualize depth and vascularization of cutaneous neoplasms, but little has been synthesized as a review for a robust level of evidence about the diagnostic accuracy of high-frequency ultrasound in dermatology. A narrative review of the PubMed database was performed to establish the correlation between ultrasound findings and histopathologic/dermoscopic findings for cutaneous neoplasms. Articles were divided into the following four categories: melanocytic, keratinocytic/epidermal, appendageal, and soft tissue/neural neoplasms. Review of the literature revealed that ultrasound findings and histopathology findings were strongly correlated regarding the depth of a cutaneous neoplasm. Morphological characteristics were correlated primarily in soft tissue/neural neoplasms. Overall, there is a paucity of literature on the correlation between high-frequency ultrasound and histopathology of cutaneous neoplasms. Further studies are needed to investigate this correlation in various dermatologic conditions.

Interventional Ultrasound in Dermatology: A Pictorial Overview Focusing on Cutaneous Melanoma Patients

Cutaneous melanoma incidence is increasing worldwide, representing an aggressive tumor when evolving to the metastatic phase. High-resolution ultrasound (US) is playing a growing role in the assessment of newly diagnosed melanoma cases, in the locoregional staging prior to the sentinel lymph-node biopsy procedure, and in the melanoma patient follow-up. Additionally, US may guide a number of percutaneous procedures in the melanoma patients, encompassing diagnostic and therapeutic modalities. These include fine needle cytology, core biopsy, placement of presurgical guidewires, aspiration of lymphoceles and seromas, and electrochemotherapy.

Imaging Assessment of Interval Metastasis from Melanoma

Interval metastasis is a particular metastatic category of metastatic localizations in the lymph nodes in patients with melanoma. Interval nodes are generally located at nonregional lymphatic stations placed along the pathway of the spread of melanoma, such as the epitrochlear lymph node station, the popliteal fossa, and the retroareolar station. Imaging techniques for evaluation of patients with interval metastasis from melanoma diseases include ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), lymphoscintigraphy (LS), and positron emission tomography (PET). A literature review was conducted through a methodical search on the Pubmed and Embase databases. The evaluation of lymph node metastases represents a critical phase in the staging and follow-up of melanoma patients. Therefore, a thorough knowledge of the imaging methods available and the interactions between the clinician and the radiologist are essential for making the correct choice for individual patients, for a better management, and to improve treatment and survival.

Effectiveness of preoperative ultrasound-guided charcoal tattooing for localization of metastatic melanoma

Purpose

Excision of metastatic lesions is an important treatment strategy in patients with malignant melanoma, both at the initial diagnosis and upon recurrence. Since nonpalpable lesions cannot be easily visualized in the surgical field, we evaluated the effectiveness of ultrasound (US)-guided tattooing using a charcoal suspension for the localization of nonpalpable metastatic lesions of malignant melanoma.

Methods

Between November 2009 and June 2019, we retrospectively reviewed 65 nonpalpable lesions in 29 patients with malignant melanoma who underwent preoperative US-guided tattooing using a charcoal suspension for histologically confirmed or suspected metastases. The characteristics of the tattooed lesions were analyzed. The effectiveness of the procedure was evaluated based on the detection rate in the surgical field and the presence or absence of residua on postoperative follow-up US. Procedure-related complications were also analyzed.

Results

Of 65 lesions, 33 (50.8%) were histologically confirmed as metastases before the tattooing procedure, while the other 32 were suspected of being metastases based on imaging studies. The mean lesion size was 9.8 mm (range, 1.3 to 24.4 mm). The final pathology revealed metastases in 59 lesions (90.8%), including lymph node (n=51), muscle (n=5), and in-transit (n=3) metastases. Sixty-one lesions (93.8%) were successfully detected intraoperatively and removed without residua on follow-up US. Four residual lesions were removed after repeated localization (n=2) or by intraoperative US (n=2). No relevant complications were noted.

Conclusion

Preoperative US-guided tattooing localization can safely and effectively delineate nonpalpable metastatic melanoma lesions to aid in successful surgical excision.

Ultrasound, CT, MRI, or PET-CT for staging and re-staging of adults with cutaneous melanoma

BACKGROUND

Melanoma is one of the most aggressive forms of skin cancer, with the potential to metastasise to other parts of the body via the lymphatic system and the bloodstream. Melanoma accounts for a small percentage of skin cancer cases but is responsible for the majority of skin cancer deaths. Various imaging tests can be used with the aim of detecting metastatic spread of disease following a primary diagnosis of melanoma (primary staging) or on clinical suspicion of disease recurrence (re-staging). Accurate staging is crucial to ensuring that patients are directed to the most appropriate and effective treatment at different points on the clinical pathway. Establishing the comparative accuracy of ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET)-CT imaging for detection of nodal or distant metastases, or both, is critical to understanding if, how, and where on the pathway these tests might be used.

OBJECTIVES

Primary objectivesWe estimated accuracy separately according to the point in the clinical pathway at which imaging tests were used. Our objectives were:• to determine the diagnostic accuracy of ultrasound or PET-CT for detection of nodal metastases before sentinel lymph node biopsy in adults with confirmed cutaneous invasive melanoma; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging in adults with cutaneous invasive melanoma:○ for detection of any metastasis in adults with a primary diagnosis of melanoma (i.e. primary staging at presentation); and○ for detection of any metastasis in adults undergoing staging of recurrence of melanoma (i.e. re-staging prompted by findings on routine follow-up).We undertook separate analyses according to whether accuracy data were reported per patient or per lesion.Secondary objectivesWe sought to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for whole body imaging (detection of any metastasis) in mixed or not clearly described populations of adults with cutaneous invasive melanoma.For study participants undergoing primary staging or re-staging (for possible recurrence), and for mixed or unclear populations, our objectives were:• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of nodal metastases;• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases; and• to determine the diagnostic accuracy of ultrasound, CT, MRI, or PET-CT for detection of distant metastases according to metastatic site.

SEARCH METHODS

We undertook a comprehensive search of the following databases from inception up to August 2016: Cochrane Central Register of Controlled Trials; MEDLINE; Embase; CINAHL; CPCI; Zetoc; Science Citation Index; US National Institutes of Health Ongoing Trials Register; NIHR Clinical Research Network Portfolio Database; and the World Health Organization International Clinical Trials Registry Platform. We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included studies of any design that evaluated ultrasound (with or without the use of fine needle aspiration cytology (FNAC)), CT, MRI, or PET-CT for staging of cutaneous melanoma in adults, compared with a reference standard of histological confirmation or imaging with clinical follow-up of at least three months' duration. We excluded studies reporting multiple applications of the same test in more than 10% of study participants.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted all data using a standardised data extraction and quality assessment form (based on the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2)). We estimated accuracy using the bivariate hierarchical method to produce summary sensitivities and specificities with 95% confidence and prediction regions. We undertook analysis of studies allowing direct and indirect comparison between tests. We examined heterogeneity between studies by visually inspecting the forest plots of sensitivity and specificity and summary receiver operating characteristic (ROC) plots. Numbers of identified studies were insufficient to allow formal investigation of potential sources of heterogeneity.

MAIN RESULTS

We included a total of 39 publications reporting on 5204 study participants; 34 studies reporting data per patient included 4980 study participants with 1265 cases of metastatic disease, and seven studies reporting data per lesion included 417 study participants with 1846 potentially metastatic lesions, 1061 of which were confirmed metastases. The risk of bias was low or unclear for all domains apart from participant flow. Concerns regarding applicability of the evidence were high or unclear for almost all domains. Participant selection from mixed or not clearly defined populations and poorly described application and interpretation of index tests were particularly problematic.The accuracy of imaging for detection of regional nodal metastases before sentinel lymph node biopsy (SLNB) was evaluated in 18 studies. In 11 studies (2614 participants; 542 cases), the summary sensitivity of ultrasound alone was 35.4% (95% confidence interval (CI) 17.0% to 59.4%) and specificity was 93.9% (95% CI 86.1% to 97.5%). Combining pre-SLNB ultrasound with FNAC revealed summary sensitivity of 18.0% (95% CI 3.58% to 56.5%) and specificity of 99.8% (95% CI 99.1% to 99.9%) (1164 participants; 259 cases). Four studies demonstrated lower sensitivity (10.2%, 95% CI 4.31% to 22.3%) and specificity (96.5%,95% CI 87.1% to 99.1%) for PET-CT before SLNB (170 participants, 49 cases). When these data are translated to a hypothetical cohort of 1000 people eligible for SLNB, 237 of whom have nodal metastases (median prevalence), the combination of ultrasound with FNAC potentially allows 43 people with nodal metastases to be triaged directly to adjuvant therapy rather than having SLNB first, at a cost of two people with false positive results (who are incorrectly managed). Those with a false negative ultrasound will be identified on subsequent SLNB.Limited test accuracy data were available for whole body imaging via PET-CT for primary staging or re-staging for disease recurrence, and none evaluated MRI. Twenty-four studies evaluated whole body imaging. Six of these studies explored primary staging following a confirmed diagnosis of melanoma (492 participants), three evaluated re-staging of disease following some clinical indication of recurrence (589 participants), and 15 included mixed or not clearly described population groups comprising participants at a number of different points on the clinical pathway and at varying stages of disease (1265 participants). Results for whole body imaging could not be translated to a hypothetical cohort of people due to paucity of data.Most of the studies (6/9) of primary disease or re-staging of disease considered PET-CT, two in comparison to CT alone, and three studies examined the use of ultrasound. No eligible evaluations of MRI in these groups were identified. All studies used histological reference standards combined with follow-up, and two included FNAC for some participants. Observed accuracy for detection of any metastases for PET-CT was higher for re-staging of disease (summary sensitivity from two studies: 92.6%, 95% CI 85.3% to 96.4%; specificity: 89.7%, 95% CI 78.8% to 95.3%; 153 participants; 95 cases) compared to primary staging (sensitivities from individual studies ranged from 30% to 47% and specificities from 73% to 88%), and was more sensitive than CT alone in both population groups, but participant numbers were very small.No conclusions can be drawn regarding routine imaging of the brain via MRI or CT.

AUTHORS' CONCLUSIONS

Review authors found a disappointing lack of evidence on the accuracy of imaging in people with a diagnosis of melanoma at different points on the clinical pathway. Studies were small and often reported data according to the number of lesions rather than the number of study participants. Imaging with ultrasound combined with FNAC before SLNB may identify around one-fifth of those with nodal disease, but confidence intervals are wide and further work is needed to establish cost-effectiveness. Much of the evidence for whole body imaging for primary staging or re-staging of disease is focused on PET-CT, and comparative data with CT or MRI are lacking. Future studies should go beyond diagnostic accuracy and consider the effects of different imaging tests on disease management. The increasing availability of adjuvant therapies for people with melanoma at high risk of disease spread at presentation will have a considerable impact on imaging services, yet evidence for the relative diagnostic accuracy of available tests is limited.

Skin cancer detection using non-invasive techniques

Skin cancer is the most common form of cancer and is globally rising. Historically, the diagnosis of skin cancers has depended on various conventional techniques which are of an invasive manner. A variety of commercial diagnostic tools and auxiliary techniques are available to detect skin cancer. This article explains in detail the principles and approaches involved for non-invasive skin cancer diagnostic methods such as photography, dermoscopy, sonography, confocal microscopy, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, optical coherence tomography, the multispectral imaging technique, thermography, electrical bio-impedance, tape stripping and computer-aided analysis. The characteristics of an ideal screening test are outlined, and the authors pose several points for clinicians and scientists to consider in the evaluation of current and future studies of skin cancer detection and diagnosis. This comprehensive review critically analyses the literature associated with the field and summarises the recent updates along with their merits and demerits.

Lymph Node Micrometastases and In-Transit Metastases from Melanoma: In Vivo Detection with Multispectral Optoacoustic Imaging in a Mouse Model

Purpose To study whether multispectral optoacoustic tomography (MSOT) can serve as a label-free imaging modality for the detection of lymph node micrometastases and in-transit metastases from melanoma on the basis of the intrinsic contrast of melanin in comparison to fluorine 18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT). Materials and Methods The study was approved by the institutional animal care and use committee. Sequential MSOT was performed in a mouse B16F10 melanoma limb lymph node metastasis model (n = 13) to survey the development of macro-, micro- and in-transit metastases (metastases that are in transit from the primary tumor site to the local nodal basin) in vivo. The in vitro limit of detection was assessed in a B16F10 cell phantom. Signal specificity was determined on the basis of a simultaneous lymphadenitis (n = 4) and 4T1 breast cancer lymph metastasis (n = 2) model. MSOT was compared with intravenous FDG PET/CT. The diagnosis was assessed with histologic examination. Differences in the signal ratio (metastatic node to contralateral limb) between the two modalities were determined with the two-tailed paired t test. Results The mean signal ratios acquired with MSOT in micrometastases (2.5 ± 0.3, n = 6) and in-transit metastases (8.3 ± 5.8, n = 4) were higher than those obtained with FDG PET/CT (1.1 ± 0.5 [P < .01] and 1.3 ± 0.6 [P < .05], respectively). MSOT was able to help differentiate even small melanoma lymph node metastases from the other lymphadenopathies (P < .05 for both) in vivo, whereas FDG PET/CT could not (P > .1 for both). In vitro, the limit of detection was at an approximate cell density of five cells per microliter (P < .01). Conclusion MSOT enabled detection of melanoma lymph node micrometastases and in-transit metastases undetectable with FDG PET/CT and helped differentiate melanoma metastasis from other lymphadenopathies. (©) RSNA, 2016 Online supplemental material is available for this article.

The Value of Sonography in the Assessment of Skin Cancers and Their Metastases

Skin cancer has become more prevalent in recent years, and finding ways to assess and characterize it prior to excision is important. Sonography can be an integral part of the preoperative and follow-up assessment of melanoma, metastatic lymph nodes, and nonmelanoma skin cancers. A review of the literature is reported, indicating that sonography appears to be effective at showing lesion thickness, defining lesion borders, and helping to identify whether lymph nodes are metastatic; however, it cannot differentiate among the types of skin cancer. Based on these findings, best practice scanning techniques are outlined for sonographers.

Role of high-resolution ultrasound and PET/CT imaging for preoperative characterization of sentinel lymph nodes in cutaneous melanoma

The purpose of our study was the comparison of high-resolution ultrasound (HRUS) and positron emission tomography combined with computerised tomography (PET/CT) in the preoperative characterization and identification of subclinical nodal metastases focusing on sentinel lymph nodes (SLN) in melanoma patients. Patients with cutaneous melanoma (CM) who received sentinel lymph node biopsy at the Department of Dermatology and Allergy, University of Bonn, between January 2009 and January 2011 had been evaluated with a retrospective computer-aided search concerning preoperative staging procedures. A combination of PET/CT and HRUS had been performed preoperatively in 20 of 123 patients. A total of 59 SLNs had been removed in those 20 patients followed by histopathologic examination. HRUS correctly identified two of 17 positive SLNs whereas PET/CT imaging identified none. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of HRUS were 11.8 % (95 % confidence interval [CI] = 3.3-34.3), 100 % (95 % CI = 91.6-100.0), 100.0 % (95 % CI = 34.2-100.0), and 73.7 % (95 % CI = 61.0-83.3), respectively. On the basis of this limited study cohort, HRUS had a better value than PET/CT in preoperative identification of positive SLNs, suggesting a possible diagnostic superiority of HRUS in general characterization of peripheral nodal disease in CM.

Role of imaging methods in metastatic melanoma

Melanoma is a malignant neoplasm of the skin deriving from melanocytes. Accounting for less than 5% of all skin cancers, melanoma is associated with approximately 75% of skin cancer-related mortality. Early detection of melanoma with surgical resection remains one of the critical factors determining favorable clinical outcomes for melanoma. Up to now, many imaging methods, such as ultrasound, computed tomography (CT), magnetic resonance imaging, and positron emission tomography/CT, have been used in the diagnosis of melanoma and metastases. This article reviews the application of imaging methods in metastatic melanoma.

Fine needle aspiration cytology of palpable and nonpalpable lymph nodes to detect metastatic melanoma

BACKGROUND

Fine needle aspiration cytology (FNAC) is usually used to evaluate palpable nodes in patients with melanoma. The goal of our study is to review the sensitivity and specificity of this technique when applied to palpable but also to nonpalpable nodes.

METHODS

FNAC was performed during 1984-2007 in 1279 patients with suspicious lesions and/or lymph nodes. Indications for biopsy included increased size and/or palpability of nodes or abnormal ultrasound findings such as increased perfusion or focal lesions within the lymph nodes. The sensitivity, specificity, and positive and negative predictive values of FNACs guided by palpation or ultrasound were calculated for all patients and for subgroups of patients with palpable nodes or nonpalpable but sonomorphologically suspicious nodes.

RESULTS

A total of 2446 FNACs were performed in 1279 melanoma patients, of which 2011 (82.2%) FNACs had clinically or histologically confirmed results. Increased size and/or palpability of nodes was observed in 376 (29.4%) of 1279 patients, and abnormal ultrasound findings occurred for 903 (70.6%), indicating that a biopsy was needed. FNACs guided by palpation had sensitivity, specificity, and positive and negative predictive values similar to that of FNACs guided by ultrasound (sensitivity = 98.4% vs 97.2%, specificity = 100% vs 99.8%, positive predictive value = 100% vs 99.9%, and negative predictive value = 95.2% vs 96.4%, for palpation-guided FNACs vs ultrasound-guided FNACs, respectively). Results did not differ between patients with the palpable nodes and patients with nonpalpable but sonomorphologically suspicious nodes.

CONCLUSIONS

Ultrasound-guided FNAC of suspicious lymph nodes and lesions in melanoma patients has a high sensitivity and specificity, and FNAC should not be limited to palpable nodes. FNAC of normal-sized nodes and/or lymph nodes with abnormal ultrasound findings can be used to identify early metastatic disease.

Previously reported sonographic appearances of regional melanoma metastases are not likely due to necrosis

OBJECTIVES

Sonography has proven to be a reliable tool in early detection of lymph node and in-transit cutaneous-subcutaneous metastases. Those metastases normally appear as hypoechoic or even anechoic lesions on sonography. It has been assumed that this appearance is due to necrosis of the lesions, but so far, that assumption has never been proven. The purpose of this retrospective study was to evaluate whether the hypoechoic appearance of melanoma metastasis is really due to tumor necrosis.

METHODS

From a radiographic database, we retrieved 212 melanoma cases imaged with sonography over a 2-year period for disease staging or follow-up. We selected 37 positive cases with 84 nodal and extranodal (satellite and in-transit) metastatic lesions and reviewed the sonograms and pathologic slides (slides available for 40 of 84 lesions). We retrospectively assessed the vascularization pattern (color Doppler images available for 78 of 84 lesions), categorizing it as poor, intermediate, or consistent. We also looked for necrosis on the histopathologic material, categorizing it into scores of 0, 1, 2, and 3 for absence of necrosis, less than 20% necrosis, 20% to 40% necrosis, and greater than 40% necrosis, respectively.

RESULTS

Despite their gray scale appearance, most melanoma lesions were vascularized on color Doppler imaging and showed limited necrosis at histopathologic analysis. Consistent vascularization on Doppler imaging, excluding substantial necrosis, was found in 44 of 78 lesions (56.4%). Poor vascularization on Doppler imaging, suggesting necrosis, was present in only 14% of the lesions. Substantial necrosis (scores of 2 and 3) was found pathologically in only 10% of the lesions.

CONCLUSIONS

Necrosis seems to be an uncommon event in melanoma metastasis and is probably not the basis for its low-level echo pattern on sonography. The hypoechoic appearance is very typical of melanoma metastasis and is likely due to massive melanomatous infiltration (with the poor echo reflectivity of melanin). However, confirmation in larger pathologically proven series is required.

Critical analysis of the ultrasonographic criteria for diagnosing lymph node metastasis in patients with cutaneous melanoma: a systematic review

The purpose of this systematic review of the literature was to evaluate the use of ultrasonography (US) in the assessment of lymph node metastasis in patients with cutaneous melanoma. A multimodal strategy was used, which was mainly based on a PubMed database search. Among the 201 cumulative articles collected (years 1989-2009), 31 were found to match all of the inclusion criteria and to provide a description of the use of US scanning in lymph node melanoma metastasis. Data extracted included the author's name and country, journal and year of publication, prospective or retrospective nature of the study, single-center or multicenter nature of the study, period when US studies were performed, US transducers used, gray scale and color Doppler criteria used for diagnosis, and data on US accuracy. The diagnostic criteria used in the 31 selected articles were critically reviewed, illustrating to the reader the discrepancies and unclear aspects identified. On the basis of this review, the need to establish definitive, clearly defined, and univocal diagnostic criteria to be applied in daily clinical practice as well as to be used in articles to be published is emphasized.

Metachronous melanoma in breast reconstruction patients

The incidence and mortality due to malignant melanoma has increased three- to four-fold across males and females in England and Wales over the past thirty years. Ninety percent of patients with primary melanoma have no clinical evidence of lymphadenopathy at presentation. In this paper we describe our management of impalpable axillary melanoma deposits in a patient with a pedicled latissimus dorsi (LD) flap reconstruction to the ipsilateral breast. No such case has been previously described in the literature.

Contemporary diagnostic imaging modalities for the staging and surveillance of melanoma patients: a meta-analysis

BACKGROUND

Meta-analyses were performed to examine the utility of ultrasonography, computed tomography (CT), positron emission tomography (PET), and a combination of both (PET-CT) for the staging and surveillance of melanoma patients.

METHOD

Patient-level data from 74 studies containing 10,528 patients (between January 1, 1990, and June, 30, 2009) were used to derive characteristics of the diagnostic tests used. Meta-analyses were conducted by use of Bayesian bivariate binomial models to estimate sensitivity and specificity. Diagnostic odds ratios [ie, true-positive results/false-negative results)/(false-positive results/true-negative results)] and their 95% credible intervals (CrIs) and positive predictive values were used as indicators of test performance.

RESULTS

Among the four imaging methods examined for the staging of regional lymph nodes, ultrasonography had the highest sensitivity (60%, 95% CrI = 33% to 83%), specificity (97%, 95% CrI = 88% to 99%), and diagnostic odds ratio (42, 95% CrI = 8.08 to 249.8). For staging of distant metastases, PET-CT had the highest sensitivity (80%, 95% CrI = 53% to 93%), specificity (87%, 95% CrI = 54% to 97%), and diagnostic odds ratio (25, 95% CrI = 3.58 to 198.7). Similar trends were observed for melanoma surveillance of lymph node involvement, with ultrasonography having the highest sensitivity (96%, 95% CrI = 85% to 99%), specificity (99%, 95% CrI = 95% to 100%), and diagnostic odds ratio (1675, 95% CrI = 226.6 to 15,920). For distant metastases, PET-CT had the highest sensitivity (86%, 95% CrI = 76% to 93%), specificity (91%, 95% CrI = 79% to 97%), and diagnostic odds ratio (67, 95% CrI = 20.42 to 229.7). Positive predictive values were likewise highest for ultrasonography in lymph node staging and for PET-CT in detecting distant metastases.

CONCLUSION

Among the compared modalities, ultrasonography was superior for detecting lymph node metastases, and PET-CT was superior for the detection of distant metastases in both the staging and surveillance of melanoma patients.

Sonography for locoregional staging and follow-up of cutaneous melanoma: how we do it

OBJECTIVE

Sonography is being used with increasing frequency in the assessment of locoregional tumor spread in patients with melanoma. Nevertheless, to maximize its practical impact, sonography should be performed with state-of-the-art equipment, by specifically trained operators, and using a careful exploration technique and well-defined diagnostic criteria. In this "how I do it"-type article, we illustrate our practical approach to sonography of cutaneous melanoma.

METHODS

We first illustrate the basic and advanced technical requirements; then we describe our exploration methods and our image interpretation approach; and finally, we report on our use of sonography as a guidance tool for interventional procedures. Special emphasis is given to methodological and interpretative clues, tricks, and pitfalls.

RESULTS

Sonography can be used in the initial staging of patients with melanoma, particularly in the screening of patients scheduled for a sentinel lymph node biopsy procedure. Additionally, sonography can be used during patient follow-up to detect locoregional recurrence earlier than palpation.

CONCLUSIONS

Sonography plays a growing role in the assessment of the superficial spread of melanoma. Nevertheless, state-of-the-art equipment and careful exploration by trained operators are necessary.

Locoregional spread of cutaneous melanoma: sonography findings

OBJECTIVE

This article reviews various aspects of locoregional spread of malignant cutaneous melanoma, as imaged with gray-scale sonography and Doppler techniques. The scenarios illustrated include disease staging (primary melanoma, satellite metastasis, in-transit metastasis, and lymphadenopathies), sentinel lymph node biopsy procedure, patient follow-up, recurrence detection, cutaneous metastasis, and sonographically guided intervention.

CONCLUSION

High-resolution sonography allows recognition of small, clinically-occult melanomatous foci. It plays a major role in locoregional staging and follow-up of patients with cutaneous melanoma.

Cutaneous melanoma: role of ultrasound in the assessment of locoregional spread

This article illustrates the various aspects of locoregional spread of cutaneous melanoma, as imaged with grayscale ultrasound (US) and Doppler techniques. High-resolution US allows recognition of small, clinically occult melanomatous foci within the skin and lymph nodes. Consequently, it plays a major role in locoregional staging and follow-up of patients with cutaneous melanoma. We discuss the possibilities and limitations of US in the initial staging (primary melanoma, satellite metastasis, in-transit metastasis, and lymphadenopathy), selection for sentinel lymph node biopsy procedure, patient follow-up, detection of recurrence, and US-guided intervention.

Sentinel lymph node biopsy in melanoma patients

Appropriate surgical management of regional lymph nodes is critical in patients with cutaneous melanoma. The use of intraoperative lymphatic mapping and sentinel lymph node biopsy (SLNB) has increased significantly in the past decade. SLNB is performed as minimally invasive procedure that provides accurate staging of melanoma patients with no clinically detectable nodal disease. In many melanoma units across the world, it became the standard for detection of occult regional node metastasis in patients with intermediate-thickness primary melanoma. Use of SLNB in patients with thin melanomas is still under evaluation. Although SLNB has been established as staging procedure in melanoma patients, its therapeutic role is still not clear. Large-scale ongoing randomized trials should elucidate whether SLNB with complete lymphadenectomy has a survival benefit in melanoma patients with early lymph node metastases compared to 'watch-and-wait' policy (observation).

Diagnosis of cutaneous tumors with in vivo confocal laser scanning microscopy

In recent years, in vivo confocal laser scanning microscopy (CLSM) has become an established method for the non-invasive examination of the skin. In vivo CLSM allows for real-time imaging of micro-anatomic cutaneous structures. It has been used to diagnose ambiguous skin tumors and to measure subclinical tumor spread prior to surgery. By additionally providing high power morphologic information, in vivo CLSM helps to reduce unnecessary biopsies. A multitude of diagnostic features for skin tumors has been published. Here we review published diagnostic in vivo CLSM features, and compare them to our own experience in 100 tumors. In combination with clinical examination and dermatoscopy, in vivo CLSM is a valuable additional tool for non-invasive skin tumor diagnosis.

Clinical outcomes of molecularly confirmed clear cell sarcoma from a single institution and in comparison with data from the Surveillance, Epidemiology, and End Results registry

BACKGROUND

The authors compared disease-specific survival (DSS) in stage-specific subgroups of patients with clear cell sarcoma, including those with lymph node metastases (N1M0) and those with distant metastases (N0M1).

METHODS

Clinical data regarding soft tissue sarcoma patients were obtained from The University of Texas M. D. Anderson Cancer Center (MDACC) (1980-2007) and the Surveillance, Epidemiology, and End Results (SEER) registry (1988-2004). When possible, clear cell sarcoma diagnoses were confirmed using fluorescence in situ hybridization or reverse-transcription polymerase chain reaction. Kaplan-Meier estimates were used to calculate DSS, and Cox multivariate analysis was performed to identify prognostic factors.

RESULTS

Fifty-two patients at MDACC and 130 SEER patients were diagnosed with clear cell sarcoma. Five-year DSS for the MDACC and SEER cohorts were 67% and 62%, respectively. Patients with N1M0 and N0M1 disease demonstrated significant differences in 5-year DSS: 74% versus 14% at MDACC (P = .014) and 52% versus 0% in SEER (P = .014). After adjustment, the hazards ratio (HR) for dying was 2.79 for N1M0 disease (95% confidence interval [95% CI], 1.32-5.91) and 11.37 (95% CI, 5.19-24.91) for N0M1 disease compared with stage II disease (P < .001). Non-Caucasian ethnicity (HR, 3.99; 95% CI, 2.27-6.99 [P < .001]) and truncal tumor site (HR, 2.41; 95% CI, 1.15-5.05 [P = .02]) were also found to be predictors of decreased DSS.

CONCLUSIONS

The findings of the current study suggest that patients with N1M0 clear cell sarcoma have 5-year DSS that is more similar to that of patients with stage III than stage IV soft tissue sarcoma.

Anatomical and molecular imaging of skin cancer

Skin cancer is the most common form of cancer types. It is generally divided into two categories: melanoma (∼ 5%) and nonmelanoma (∼ 95%), which can be further categorized into basal cell carcinoma, squamous cell carcinoma, and some rare skin cancer types. Biopsy is still the gold standard for skin cancer evaluation in the clinic. Various anatomical imaging techniques have been used to evaluate different types of skin cancer lesions, including laser scanning confocal microscopy, optical coherence tomography, high-frequency ultrasound, terahertz pulsed imaging, magnetic resonance imaging, and some other recently developed techniques such as photoacoustic microscopy. However, anatomical imaging alone may not be sufficient in guiding skin cancer diagnosis and therapy. Over the last decade, various molecular imaging techniques (in particular single photon emission computed tomography and positron emission tomography) have been investigated for skin cancer imaging. The pathways or molecular targets that have been studied include glucose metabolism, integrin α_vβ₃, melanocortin-1 receptor, high molecular weight melanoma-associated antigen, and several other molecular markers. Preclinical molecular imaging is thriving all over the world, while clinical molecular imaging has not lived up to the expectations because of slow bench-to-bedside translation. It is likely that this situation will change in the near future and molecular imaging will truly play an important role in personalized medicine of melanoma patients.

Sentinel lymph node biopsy for melanoma: aspects of pathologic assessment

Sentinel lymph node (SLN) biopsy affords an accurate, minimally invasive means of staging and determining prognosis in patients with melanoma and for identifying those patients who may benefit from complete regional lymph node dissection. Careful and accurate histopathologic assessment of SLNs is critical to achieving optimal reliability of the technique. Micromorphometric parameters of melanoma deposits in SLNs have been shown to be predictive of regional non-SLN involvement and of clinical outcomes. Several non-histopathologic methods of SLN evaluation have been investigated, and while some of them show promise for the future, excision and histopathologic examination currently remains the gold standard for the evaluation of SLNs.