Primary Malignant Melanoma in the Parotid Gland: A Case Report and Literature Review

Primary melanoma of the parotid gland is an extremely rare and challenging tumor with a poor prognosis, and its ultrasonic characteristics have yet to be reported. This article presents a case of a 77-year-old man with a left parotid mass that was confirmed as a melanoma following surgery. The ultrasonic features of melanoma were examined in detail, with a particular focus on their diagnostic value. Furthermore, we summarized the clinical characteristics, treatment options, and outcomes associated with primary melanoma of the parotid gland based on a thorough analysis of the available literature.

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.

Melanoma Detection by AFM Indentation of Histological Specimens

Melanoma is visible unlike other types of cancer, but it is still challenging to diagnose correctly because of the difficulty in distinguishing between benign nevus and melanoma. We conducted a robust investigation of melanoma, identifying considerable differences in local elastic properties between nevus and melanoma tissues by using atomic force microscopy (AFM) indentation of histological specimens. Specifically, the histograms of the elastic modulus of melanoma displayed multimodal Gaussian distributions, exhibiting heterogeneous mechanical properties, in contrast with the unimodal distributions of elastic modulus in the benign nevus. We identified this notable signature was consistent regardless of blotch incidence by sex, age, anatomical site (e.g., thigh, calf, arm, eyelid, and cheek), or cancer stage (I, IV, and V). In addition, we found that the non-linearity of the force-distance curves for melanoma is increased compared to benign nevus. We believe that AFM indentation of histological specimens may technically complement conventional histopathological analysis for earlier and more precise melanoma detection.

Ultrasound Examination of the Lymphatic Drainage Area and Regional Lymph Nodes in Melanoma Patients with In-Transit Metastases

BACKGROUND

In-transit metastases (ITMs) are cutaneous or subcutaneous regional metastases that may occur in patients with melanoma. ITMs are often multiple and new lesions tend to appear over time. Ultrasonography can detect impalpable subcutaneous tumors.

OBJECTIVE

The aim of this study was to assess the value of ultrasound examination in detecting additional, non-palpable ITMs and to determine their relevance.

METHODS

Melanoma patients with ITMs who underwent regional ultrasound examination of the skin and subcutaneous tissue between the wide excision scar of the primary melanoma and the regional lymph node field were identified. In most, ultrasound assessment also included the regional lymph node field. Relevant data were collected and analyzed.

RESULTS

Twenty-eight patients presenting with a total of 40 ITMs were included. Ultrasound examination identified additional ITMs in 15 patients (54%). No nodal recurrences were detected. Most additional lesions were found closer to the regional lymph nodes than the original ITMs. Management was influenced by the ultrasound findings in nine patients (32%), five of whom had more extensive surgery, three received systemic drug therapy instead of surgery, and in one patient surgery was delayed and follow-up intensified. In one patient, only subcutaneous fat was found in the excised specimen and the ultrasound was classified as false-positive.

CONCLUSION

In melanoma patients with ITMs, ultrasonography of the lymphatic drainage area provided valuable information, as additional ITMs were identified in more than half of these patients and management was influenced in one-third.

Recent developments in the medical and surgical treatment of melanoma

Increasing knowledge of the biology of melanoma has led to significant advances in drug development to fight this disease. Surgery is the primary treatment for localized disease and is an integral part of management in patients with more advanced disease. The last decade has become the era of targeted therapy in melanoma and has revolutionized the treatment of this disease. Since 2011, 4 new agents have been approved for the treatment of patients with metastatic melanoma: ipilimumab, vemurafenib, dabrafenib, and trametinib. Several new agents are currently in phase 3 trials with hopes of even more agents being approved for this once "untreatable" disease. How to integrate surgical options with more effective systemic therapies has become a new challenge for physicians. This review will provide an update on current surgical options, highlight the pathway to the development of the newly approved agents, and further discuss new treatments that are on the horizon.

An introduction to primary skin imaging

Dermatology is a field in which clinical examination is heavily relied upon for diagnosis. When required, a tissue biopsy may also be performed to confirm the diagnosis. Recent advances in imaging techniques have been applied to cutaneous lesions to improve diagnostic accuracy without the need for biopsy. These new imaging techniques are reviewed for their developing role in dermatology.

Preoperative 15-MHz ultrasound assessment of tumor thickness in malignant melanoma

BACKGROUND

Tumor thickness is of great importance in the management of cutaneous malignant melanoma (MM): this variable not only affects prognosis but is also a key factor in planning surgical margins and selecting candidates for sentinel node biopsy. Breslow depth is the standard histologic measure of thickness, but technological advances have provided imaging techniques such as cutaneous ultrasound that can potentially assess tumor thickness and enable prompt initiation of definitive treatment.

OBJECTIVES

a) To evaluate the utility of ultrasound assessment of tumor thickness in MM, and b) to analyze histologic variables that affect ultrasound assessments of thickness.

MATERIALS AND METHODS

Retrospective study of a consecutive series of 79 primary cutaneous MMs in which tumor thickness had been assessed by 15-MHz ultrasound before surgery. We gathered data from histology reports, studying Breslow depth and the presence of ulceration, regression, inflammatory infiltrate, and associated nevi. Correlation coefficients were calculated to evaluate the strength of association between Breslow depth and thickness assessed by ultrasound. We also calculated the sensitivity, specificity, and positive and negative predictive values of ultrasound measurement in the diagnosis of MMs more than 1mm thick. Associations between histologic variables and the overestimation of thickness by ultrasound were also analyzed.

RESULTS

The 79 primary MMs studied had a mean (SD) Breslow depth of 0.8 (1.4) mm. There was moderate correlation and agreement between Breslow depth and the ultrasound assessment of thickness (Pearson correlation coefficient, 0.678; intraclass correlation coefficient, 0.78). The tendency of ultrasound to overestimate thickness was nonsignificantly related to the presence of a moderate to intense infiltrate and associated nevi (P>.05). The sensitivity of ultrasound for the diagnosis of MM over 1mm thick was 82%; specificity was 80%, and positive and negative predictive values were 54% and 94%, respectively.

CONCLUSIONS

Ultrasound imaging quite correctly identifies thin MMs and can be useful for planning adequate surgical margins; however, there are limitations on its usefulness in the diagnosis of thick MMs. Additional studies are required to confirm whether certain histologic characteristics, such as the presence of a moderate to intense inflammatory infiltrate or associated nevi can lead to overestimation of thickness by ultrasound, limiting the clinical utility of this imaging technique in MM management.

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.

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.

Ultrasound morphology criteria predict metastatic disease of the sentinel nodes in patients with melanoma

PURPOSE We have shown that ultrasound (US) -guided fine needle aspiration cytology (FNAC) can accurately identify the sentinel node (SN). Moreover, US-guided FNAC before the surgical SN procedure could identify up to 65% of all SN metastases. Herein we analyzed in detail the different US morphologic patterns of SN metastases. PATIENTS AND METHODS From July 2001 to December 2007, a total of 650 patients with melanoma scheduled for sentinel lymph node dissection were examined. We present the first 400 with sufficient follow-up (mean 40, median 39 months). Several morphologic characteristics were scored. In case of suspicious/clearly malignant US patterns a FNAC was performed. The final histology was considered the gold standard. Results Median Breslow was 1.8 mm. The sensitivity and positive predictive value of the most important factors were: peripheral perfusion (PP) present (77% and 52%, respectively), loss of central echoes (LCE; 60% and 65% respectively), and balloon shape (BS; 30% and 96% respectively). Together these factors have a sensitivity of 82% and PPV of 52% (P < .001). PP identified more patients with lower volume disease. PP and combined BS and LCE were independent prognostic factors for survival (hazard ratio, 2.19; P < .015; and hazard ratio, 5.50; P < .001, respectively). CONCLUSION Preoperative US and FNAC can identify 65% of SN metastases and thus reduce the need for surgical SN procedures. Peripheral perfusion is an early sign of involvement and of crucial importance to achieve a high identification rate. Balloon shape and loss of central echoes are late signs of metastases. We recommend US evaluation to identify those patients, who can directly proceed to a complete lymph node dissection after a positive US-guided FNAC of the SN.

Targeted High-Resolution Ultrasound Is Not an Effective Substitute for Sentinel Lymph Node Biopsy in Patients With Primary Cutaneous Melanoma

Purpose

To reassess traditional ultrasound descriptors of sentinel lymph node (SLN) metastases, to determine the minimum cross-sectional area (CSA) of an SLN metastasis detectable by ultrasound (US), and to establish whether targeted, high-resolution US of SLNs identified by lymphoscintigraphy before initial melanoma surgery can be used as a substitute for excisional SLN biopsy.

Methods

US was performed on SLNs identified in 871 lymph node fields in 716 patients. SLN biopsy was performed within 24 hours of lymphoscintigraphy and US examination. The CSA of each SLN metastatic deposit was determined sonographically and histologically.

Results

The sensitivity of targeted US in the detection of positive SLNs was 24.3% (95% CI, 19.5% to 28.7%), and the specificity was 96.8% (95% CI, 95.9% to 97.7%). The sensitivity was highest for neck SLNs (45.8%) and improved with greater Breslow thickness. The median histologic CSA of the SLN metastatic deposits was 0.39 mm2 (12.75 mm2 for US true-positive results and 0.22 mm2 for US false-negative results). True-positive, US-detected SLNs had significantly greater CSAs (t test P < .001) than undetected SLN metastases and were more likely to be spherical in cross-section. More than two sonographic descriptors of SLN metastases or rounding of the node alone were factors highly suggestive of a melanoma deposit.

Conclusion

US is not an appropriate substitute for SLN biopsy, but it is of value in preoperative SLN assessment and postoperative monitoring.

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.