Multimethod imaging, staging, and spectrum of manifestations of metastatic melanoma

Malignant melanoma and lymph node metastases appearing as hyperattenuating masses on computed tomography in a dog

A 16-year-old male castrated Dachshund cross dog was referred for a dental and a mass on the right side of the face. CT revealed several heterogenous precontrast hyperattenuating masses within the subcutaneous tissue over the masseter muscle, demonstrating marked contrast uptake. The ipsilateral mandibular lymph nodes were mildly enlarged and markedly hyperattenuating on precontrast images. A histopathological final diagnosis of malignant melanoma with regional lymph node metastasis was made, and the hyperattenuating appearance was postulated to be due to its melanin content. This is the first published report of melanoma appearing as hyperattenuating masses on CT in small animals.

An unusual case of metastatic melanoma in subcutaneous tissue presenting as a solitary cystic mass with fluid levels

Malignant melanoma is a common and often aggressive neoplasm of the skin arising from melanocytes. Metastatic melanoma is known for its diverse clinical manifestations, and can present with atypical features prior to diagnosis of the primary lesion, which can pose a diagnostic challenge. We report a rare case of metastatic melanoma in a 67 year-old male who presented with a painless, enlarging mass in the right axilla over a 4 week period. Ultrasound and magnetic resonance imaging (MRI) scans revealed a well-defined solitary, cystic appearing lesion in the right axilla with a distinct fluid-fluid level. An ultrasound guided biopsy of the lesion diagnosed a metastatic melanoma. While haemorrhagic distant metastases are a well-recognised complication of malignant melanoma, particularly in the brain and lung, soft tissue metastases presenting with fluid-fluid levels is not well described in the literature. The case highlights the importance of considering the differential of melanoma metastasis when encountered with such a lesion and importance of ultrasound guided biopsy for histopathological confirmation, as the imaging features can mimic that of a haemorrhagic soft tissue sarcoma, the management of which differs substantially from that of melanoma.

Skin Malignancies: Imaging Review with Radiologic-Histopathologic Correlation

Skin malignancies are commonly encountered as primary or incidental findings. Neoplasms that affect the skin include primary (basal cell carcinoma, squamous cell carcinoma, melanoma, and Merkel cell carcinoma) and secondary (mesenchymal neoplasms, lymphoma, and metastases) tumors. Imaging provides valuable anatomic information (tumor size, depth of involvement, presence of distant metastasis, and data for guiding biopsy) and functional information (metabolic activity and sentinel node mapping data). This information, in addition to biopsy results, improves the histopathologic characterization of tumors and treatment planning. Various histopathologic types of the same entity exhibit different biologic behavior and have different imaging features. Familiarity with the multimodality imaging features, histopathologic characteristics, and various modes of dissemination (direct invasion; perineural, lymphatic, and hematogenous spread) of the most common skin malignancies helps radiologists narrow the differential diagnosis in clinical practice. ©RSNA, 2023 Supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center.

Metastatic melanoma presenting as rapidly enlarging hepatic cysts

Malignant melanoma is a highly aggressive disease with a propensity for metastatic spread. Although recent advances in targeted therapies have improved outcomes, effective screening for metastasis remains an important area of further research. We present a case of a man in his 70s who was recently diagnosed with recurrent, locally advanced melanoma. He presented with abdominal fullness, jaundice, and poor appetite. MR imaging of the abdomen revealed innumerable hepatic cysts with internal fluid-fluid levels which were markedly increased in size and number from recent imaging. These findings necessitated a broad differential that included parasitic or bacterial infection, metastases, or drug-induced polycystic liver disease. Subsequent biopsy revealed metastatic melanoma consistent with the patient's primary tumor. The patient was ultimately transitioned to comfort care measures due to the burden of the liver metastases and passed away shortly after presentation.

Cutaneous Malignant Melanoma Metastatic to the Larynx and Trachea: A Case Report and Review of the Literature

Malignant melanoma rarely develops in mucous membranes. Statistical data show that approximately 0.6-9.3% of patients with cutaneous malignant melanoma will develop metastases in the upper aerodigestive tract mucosa, and within these metastatic sites, the least common are the laryngeal and tracheobronchial ones. This exceedingly rare clinical entity has no clear treatment recommendations; radical surgery does not seem to benefit the patient in term of life expectancy. We present the case of a 56-year-old male patient diagnosed with laryngeal and tracheobronchial melanoma metastases. Prior to admission to our clinic the patient had a personal history of malignant melanoma of the nuchal region operated on 7 years ago, malignant melanoma of the gallbladder and metastatic left axillary polyadenopathy for which he underwent surgical treatment 3 months prior. Histopathological and immunohistochemical reports established the diagnosis of laryngeal metastasis of malignant melanoma. Genetic molecular analysis was positive for B-Raf (BRAF) gene and hence Vemurafenib was administered, with a favorable outcome at the one-year follow-up. Nevertheless, there are currently no clear universally accepted guidelines for the treatment of laryngeal melanoma, mainly due to the rarity of this clinical entity. We conducted a review of similar cases reported in the literature. Interestingly, reviewing the cases reported in the literature, it appears that laryngeal metastases of a primary cutaneous melanoma are more common in men, with an average time to metastasis of 4.3 years.

Malignant melanoma resection and reconstruction with the first manifestation of lumbar metastasis: A case report

BACKGROUND

Malignant melanoma (MM) has shown an increasing incidence worldwide, and a potential to metastasize to almost any part of the body. Clinically, MM with bone metastasis as the initial manifestation is extremely rare. Spinal metastatic MM can cause spinal cord or nerve root compression, resulting in severe pain and paralysis. Currently, the primary clinical treatments for MM are surgical resection in conjunction with chemotherapy, radiotherapy, and immunotherapy.

CASE SUMMARY

Here, we report the case of a 52-year-old male who presented to the clinic with progressive low back pain and limited nerve function. No primary lesion or spinal cord compression was detected from computed tomography and magnetic resonance imaging of the lumbar vertebrae and positron emission tomography scan. A lumbar puncture biopsy confirmed the diagnosis of lumbar spine metastatic MM. Following surgical resection, the patient’s quality of life improved, symptoms were relieved, and comprehensive treatment was initiated, which prevented recurrence.

CONCLUSION

Spinal metastatic MM is clinically rare, and may cause neurological symptoms, including paraplegia. Currently, the clinical treatment plan consists of surgical resection in combination with chemotherapy, radiotherapy, and immunotherapy.

Gastric ectopic pancreas in magnetic resonance imaging: A review of 2 cases

Gastric ectopic pancreas (EP) is an uncommon congenital anomaly in which pancreatic tissue with no anatomic connection to the main pancreas is found in the stomach. Gastric EP is often discovered incidentally when a nonspecific submucosal tumor is found in endoscopic studies or other imaging examinations. Tissue characterization by biopsy or fine-needle aspiration is required as endoscopic findings alone cannot exclude malignancy. The authors present 2 cases of gastric EP incidentally detected on endoscopy, which underwent further characterization by magnetic resonance imaging (MRI). In both cases, MRI showed submucosal gastric lesions, isointense to the orthotopic pancreas in all sequences, including hyperintensity on T1-weighted images. Furthermore, the lesions showed bright arterial phase enhancement, paralleling the native pancreas. MRI may provide the best non-invasive imaging method for evaluating gastric submucosal lesions. This report intends to show that EP shows a characteristic MR appearance that allows differentiation from other submucosal lesions.

Imaging More than Skin-Deep: Radiologic and Dermatologic Presentations of Systemic Disorders

Background: Cutaneous manifestations of systemic diseases are diverse and sometimes precede more serious diseases and symptomatology. Similarly, radiologic imaging plays a key role in early diagnosis and determination of the extent of systemic involvement. Simultaneous awareness of skin and imaging manifestations can help the radiologist to narrow down differential diagnosis even if imaging findings are nonspecific. Aims: To improve diagnostic accuracy and patient care, it is important that clinicians and radiologists be familiar with both cutaneous and radiologic features of various systemic disorders. This article reviews cutaneous manifestations and imaging findings of commonly encountered systemic diseases. Conclusions: Familiarity with the most disease-specific skin lesions help the radiologist pinpoint a specific diagnosis and consequently, in preventing unnecessary invasive workups and contributing to improved patient care.

Metastatic melanoma concurrent to the urinary bladder and endometrium: Case report

We report a case of a 47-year-old woman with a history of acral lentiginous melanoma, left great toe subungual primary, metastatic to the lungs, brain, and spleen, presenting with lower urinary tract symptoms. She had also palpated and removed a dark mass from her vaginal canal. Magnetic resonance imaging (MRI) showed polypoidal lesions within the urinary bladder and the endometrium. The suspected differential diagnosis was endometrial and bladder melanoma metastases, based on her cancer history and MRI findings. The patient underwent cystoscopy with transurethral resection of the bladder tumor and endometrial biopsy, and pathology was consistent with metastatic melanoma. Bladder and endometrial metastatic lesions are exceedingly rare. Herein, we describe an unusual case of metastatic melanoma concurrent to the urinary bladder and endometrium.

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.

Primary Retroperitoneal Malignant Melanoma with Involvement of Iliac Artery and Vein

Primary retroperitoneal melanoma is a very rare extracutaneous presentation of melanoma. In this case report, we present a 65-year-old female with unilateral lower extremity edema secondary to occlusion of iliac vessels by a primary retroperitoneal melanoma tumor. We also review the findings in other cases previously described in the literature.

Imaging of gallbladder metastasis

Gallbladder metastasis (GM) is a rare condition, often with a late diagnosis or detected upon autopsy. There is no extensive literature on the imaging diagnosis of GM. Here we present a comprehensive review of the literature with the aim of helping to interpret the clinical findings and imaging features of such patients. Few studies on GM are reported in literature. GM by melanoma accounts for about 55.6% of cases. The remaining cases origin from breast cancer (13.6%), hepatocellular carcinoma (13.6%), renal cell carcinoma (6.8%), lung cancer (4.5%), lymphoma (3.5%) and gastric cancer (2.4%). The most common clinical presentation of GM is abdominal pain from cholecystitis due to obstruction of the cystic duct. The main ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI) findings that clinicians and radiologists should consider in their everyday medical activity were discussed. The diagnosis of GM was often achieved through a combination of more than one imaging modality. In more than 90% of cases, the diagnosis of GM is often late and combined with other organs involvement in the terminal stage of the malignancy. The knowledge of the clinical features and different imaging techniques through careful evaluation of the gallbladder can help to achieve early diagnosis and avoid misdiagnosis or false negative results.

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Magnetic Resonance Imaging, the Virtual Biopsy of Mesenteric Masses

ABSTRACT

The mesentery may be affected by multiple disease processes. Magnetic resonance imaging aids as a virtual pathological biopsy tool in the assessment of mesenteric masses because of superior soft tissue contrast and characterization. In this comprehensive review, we describe in detail the magnetic resonance imaging features of some solid and cystic mesenteric masses, with an emphasis on lesion-specific signal characteristics on T1- and T2-weighted images, diffusion-weighted imaging, and enhancement features on the dynamic postcontrast phase that aid in narrowing the differential diagnosis.

PET/CT in restaging, prognosis, and recurrence in patients with malignant melanoma

Background

Cutaneous malignant melanoma (CMM) is a highly aggressive tumor with high tendency of return despite complete surgical removal. It has a high risk of dissemination to regional lymph nodes and visceral organs. The prognosis is highly dependent on lymph node involvement and distant metastases. Positron Emission Tomography with Computed Tomography (PET/CT) is a valuable non-invasive tool for the diagnosis and staging of patients with MM. The purpose of the present study was to evaluate the role of integrated (PET/CT) in staging, restaging, prognosis, and prediction of recurrence in patients with malignant melanoma.

Results

Fifty malignant melanoma patients with age ranged from 28 to74 years (mean age 55.94 + 13.40 years) were 28 males (mean age 56.71 + 12.82) and 22 females (mean age 54.95 + 14.34). All our patients were histopathologically proven to have malignant melanoma. Twenty-one patients came for initial staging by 18F-FDG PET/CT. Their findings were compared with the reference standards and showed the sensitivity of 93.33%, specificity of 60%, and accuracy of 85.71% for primary staging. 18F-FDG PET/CT scan in 11 clinical suspicion patients of relapse after treatment showed the sensitivity of 100%, specificity of 66.66%, positive predictive value of 88.88%; negative predictive value of 100%; and accuracy of 90.90%. FDG-PET/CT of whole body scan in 18 cases of stage IV melanoma showed sensitivity of 100%, specificity of 66.66%, and overall accuracy of 94.44% for detection of distant metastases. SUVmean and SUVmax in all studied groups were significantly higher in true positive more than true negative or false-positive patients diagnosed by PET/CT with high sensitivity (82.88–100%).

Conclusion

PET/CT imaging enhanced diagnostic performance in detection of the primary malignancy, in follow-up of high-risk patients and patients with suspected or known local or distant recurrence, and in restaging of patients with known distant metastatic disease to assess tumor response.

Assessment of Cutaneous Melanoma by Use of Very- High-Frequency Ultrasound and Real-Time Elastography

OBJECTIVE

The primary objective of this study was to evaluate the usefulness of very-high-frequency ultrasound as tool for assessment of skin melanoma by investigation of the correlation between the ultrasound measurement of the thickness of a melanoma and the histopathologically measured Breslow index. The secondary objective was to assess the potential role of real-time elastography in the preoperative evaluation of skin melanoma.

SUBJECTS AND METHODS

The study included 42 cutaneous melanoma lesions in 39 adult subjects examined in the division of ultrasound of a department of radiology between September 2011 and January 2015. Gray-scale sonographic features at 40 MHz (thickness, echogenicity, contour) and real-time strain elastographic (qualitative and semiquantitative, strain ratio) characteristics were evaluated and compared with the pathologic results.

RESULTS

The melanoma lesions had a homogeneous hypoechoic appearance with a regular contour and stiff or medium consistency. The mean difference between Breslow index and ultrasound thickness was -0.05 mm (95% CI, -0.24 to 0.13 mm), sustaining the absence of significant differences between these two measurements. A strong relation was identified between real-time elastographic appearance and strain ratio for the relations between lesion and hypodermis and between lesion and neighboring dermis (p < 0.002) or hypodermis.

CONCLUSION

Our study showed that very-high-frequency ultrasound and real-time elastography can be useful examinations for comprehensive preoperative evaluation of cutaneous melanoma.

Endobronchial metastases from melanoma: a survival analysis

BACKGROUND

Metastatic spread to the tracheobronchial tree from other than bronchopulmonary tumors is a common clinical problem. However, malignant melanoma, a highly metastatic potential tumor, is rarely metastasing in the airways. Therefore little is known about survival of patients with endobronchial metastasis from melanoma.

OBJECTIVES

The aim of our study was to assess survival of patients with endobronchial metastasis of melanomas according to clinical and radiological features, to determine any possible factor affecting survival.

METHODS

This retrospective study included 19 patients who underwent a bronchoscopy from 11 different hospitals. Data about patients' demographics, symptoms, radiographic, endoscopic findings and treatment were investigated to evaluate any possible impact on survival.

RESULTS

Endobronchial metastases occurred at a median of 48 months (range 0-120) following the diagnosis of the primary tumor. About 73.7% of patients had other proven metastases when the endobronchial involvement was diagnosed. Symptoms are not specific as well as radiological features. Median overall survival of the studied population was 6 months (range 1-46). Factors of poor survival were multiple metastatic sites (P = 0.019), pleural (P = 0.0014) and soft tissue metastasis (P = 0.024). Different treatment modalities applied in our patients showed no effect on survival.

CONCLUSION

Patients with endobronchial metastasis have overall poor survival, affected by multiple organ involvement, the presence of pleural and soft tissue disease, while no impact on survival has been shown by any treatment applied.

[Staging of cutaneous malignant melanoma by CT]

Malignant melanomas are a challenge in radiological imaging diagnostics as they may metastasize into every organ and tissue. Cross-sectional imaging, in particular positron emission tomography computed tomography (PET/CT) and whole body magnetic resonance imaging (MRI), are considered the standards in the staging of melanomas. Because of its excellent availability CT, however, remains a widely employed staging modality. Familiarity with the manifold CT morphology of metastasized melanomas as it is described here is essential when interpreting dedicated CT and in addition useful when interpreting PET/CT results. In individual cases CT can assist in the detection of transient metastases. In the detection of locoregional lymph node metastases CT has a median sensitivity and specificity in meta-analyses of at best 61 % and 97 %, respectively, which is inferior to the performance of ultrasound (96 % and 99 %, respectively). According to meta-analyses, in the assessment of systemic tumor spread CT can detect the majority of metastases with a sensitivity and specificity of 51-63 % and 69-78 %, respectively, which is inferior to MRI and PET/CT. Therefore, if an exact staging is required for critical management decisions, MRI or PET/CT should be employed whenever possible.

Melanoma: diagnosis, staging, and treatment. Consensus group recommendations

The incidence of malignant melanoma is increasing worldwide. In Spain, its incidence is increasing faster than any other cancer type, with a 5-year survival rate of about 85%. The impact and characteristics of malignant melanoma in the Spanish population can be ascertained from the national melanoma registry of the Academia Española de Dermatología y Venereología. This review presents consensus group recommendations for the diagnosis, staging and treatment of malignant melanoma in Spain. Incidence and mortality are discussed, as well as evaluation of various prevention and treatment strategies. Prognostic factors, such as BRAF and C-KIT mutations, which are expected to become routine staging procedures over the next few years, are outlined, especially in relation to treatment options. The use of recently approved targeted agents such as ipilimumab, a cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) inhibitor, and vemurafenib, a BRAF inhibitor, in metastatic disease are also discussed.

Hyperdense endobronchial mass - a rare manifestation of metastatic melanoma

Parenchymal lung metastases are common in malignant melanoma. However, endobronchial metastatic melanoma is uncommon. In this report, we describe a patient with a hyperdense endobronchial mass diagnosed as a melanoma metastasis. We review the imaging findings of pulmonary metastatic melanoma and discuss the differential diagnosis of an endobronchial mass in adults.

Perioral lesions and dermatoses

The purpose of this article is to review the common neoplasms, infections, and inflammatory dermatoses that may present around or near the mouth. Dental professionals are well positioned to evaluate perioral skin conditions, further contributing to patients' general health. This article includes a review of seborrheic keratosis, warts, actinic keratoses, actinic cheilitis, and squamous cell carcinoma, among several other perioral cutaneous lesions.

Treatment of liver metastases from uveal melanoma: a retrospective single-center analysis

BACKGROUND

Metastatic liver melanoma is a rare event in the Chinese population with extremely poor prognosis. Any treatment that controls a metastatic hepatic lesion potentially prolongs survival. This study aimed to evaluate the survival of patients with isolated liver metastases from uveal melanoma treated with partial hepatectomy or non-surgical management and to find the best therapeutic modality for these patients.

METHODS

From January 1996 to September 2008, eight patients with liver metastases secondary to uveal melanoma were admitted to our hospital. Five patients underwent partial hepatectomy and 3 received other treatments (TACE, RFA, PEI). Their medical records were reviewed and overall survival was analyzed.

RESULTS

The patients comprised 3 men and 5 women, with a median age of 44 years. Six patients presented with liver metastases at the time the primary tumor was diagnosed. The interval from the diagnosis of uveal melanoma to liver metastasis in the remaining 2 patients was 9.5 and 32.5 months, respectively. The median survival after the treatment of liver metastasis was 11.5 and 7.5 months in the surgical and non-surgical groups, respectively. There was no procedure-related mortality in the whole study cohort.

CONCLUSIONS

Partial hepatectomy or other therapies were safe and feasible for isolated liver metastases from uveal melanoma. Aggressive treatment with multidisciplinary modalities may result in prolonged survival.

Advances in therapy for melanoma brain metastases

Melanoma cells frequently metastasize to the brain, and approximately 50% of patients with metastatic melanoma develop intracranial disease. Historically, central nervous system dissemination has portended a very poor prognosis. Recent advances in systemic therapies for melanoma, supported by improved local therapy control of brain lesions, have resulted in better median survival for these patients. We review current local and systemic approaches for patients with melanoma brain metastases.

Utility of dual phase liver CT for metastatic melanoma staging and surveillance

RATIONALE AND OBJECTIVES

To evaluate the clinical utility of dual phase computed tomography (CT) for assessment of hepatic metastases in patients with metastatic melanoma.

MATERIALS AND METHODS

A retrospective case-control study of dual phase CT examinations consisting of late hepatic arterial and portal venous phases performed on patients with melanoma was undertaken. In 2010, 420 dual phase CT examinations were performed on 188 patients. Of these, 46 CT examinations on 24 patients with hepatic metastases were combined with 52 control studies for evaluation. Two blinded reviewers independently evaluated single portal venous phase alone and dual phase imaging on separate occasions. The presence of hepatic lesions, the conspicuity of the lesions, and the likelihood that the detected lesions were metastases was recorded. Agreement between readers, sensitivity and specificity was calculated.

RESULTS

In no case was hepatic metastatic disease only apparent on arterial phase imaging. Arterially enhancing hepatic lesions only visible on the arterial phase or much more conspicuous on the arterial phase were present in 10 studies (10%), all of which were benign. Liver metastases were rated as being more accurately assessed on the portal venous phase in up to 100%. In a per scan analysis dual phase and venous phase imaging had similar sensitivities of 96% (95%, CI: 86-100) and 98% (95%, CI: 89-100), respectively.

CONCLUSION

Single portal venous phase imaging is adequate for staging and surveillance in patients with metastatic melanoma.

Whole-body MRI including diffusion-weighted imaging compared to CT for staging of malignant melanoma

BACKGROUND

Whole-body (WB) magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI), has been increasingly used for the detection of metastatic disease.

PURPOSE

To assess the value of WB MRI including DWI compared to computed tomography (CT) for staging of malignant melanoma. A second aim was to assess the value of DWI in addition to conventional MR sequences for the detection of lesions.

MATERIAL AND METHODS

WB MRI with DWI and CT chest, abdomen, and pelvis were performed in 23 patients with histologically confirmed malignant melanoma. CT before and after the MRI examinations and the clinical follow-up was utilized as the standard of reference.

RESULTS

WB MRI and WB DWI detected 345 and 302 lesions, respectively, compared to 397 lesions with CT. The sensitivity of WB MRI and WB DWI varied considerably in different regions of the body. In the lungs, WB MRI and WB DWI showed 63% and 47% true-positive lesions, respectively. WB MRI and WB DWI detected 56 bone lesions in 12 patients compared to 42 lesions in 8 patients with CT. In addition, WB MRI and WB DWI could detect 68 lesions outside the field of view of CT in six patients.

CONCLUSION

WB MRI is still not ready to replace CT for staging of malignant melanoma, especially in the thorax region. However, WB MRI is advantageous for detection of bone lesions and lesions outside the investigated volume of the conventional CT. When WB MRI is evaluated, both DWI and conventional MRI sequences must be scrutinized.

[Positron emission tomography/magnetic resonance: Present and future]

PET/MRI has recently been introduced onto the market after several years of research and development. The simple notion of combining the molecular capabilities of the PET and its difference available radiotracers with the excellent tissue resolution of the MRI and wide range of multiparametric imaging techniques has generated great expectations upon the possible uses of this technology. Many challenges must be worked out. However, the most urgent one is the derivation of the MRI-based attenuation correction map. This is especially true because the PET/CT has already demonstrated a huge clinical impact within oncology, neurology and cardiology during its short existence. Despite these difficulties, research is being carried out at a rapid pace in the clinical setting in order to find areas in which the PET/MRI is superior to other existing imaging modalities. In the few initial publications found up to date that have analyzed its clinical role, areas have been identified where PET/CT can migrate to PET/MRI, even if only to suppress the CT scan's ionizing radiation. Nonetheless, there are many theoretical applications in which the PET/MRI can further improve the field of diagnostic imaging. In this article, we will review those applications, the evidence existing regarding the MRI and PET that support those premises as well as that which we have learned in the short period of one year with our experience using the PET/MRI.

Melanoma metastases in the abdomen and pelvis: Frequency and patterns of spread

AIM: To investigate the frequency, typical and atypical locations and patterns of melanoma metastases identifiable by computed tomography (CT) in the abdomen and pelvis.

METHODS: We performed a retrospective review of index CT examinations of the abdomen and pelvis in patients with melanoma and recorded all findings suggestive of metastatic disease.

RESULTS: Metastases were present on 36% (181/508) of the index examinations and most commonly involved the liver (47%) and pelvic lymph nodes (27%). Lower extremity primaries had the highest rate of metastasis (52%). Ocular and head and neck melanomas have a predilection to metastasize to the liver (hepatic involvement in 70% and 63%, respectively, of patients with metastatic disease) and metastases from lower extremity primaries most commonly involve pelvic lymph nodes (54% of patients with metastatic disease). Metastases to atypical locations were present in 14% of patients and most commonly occurred in the subcutaneous tissue and spleen. Primary tumors of the lower extremity, back and head and neck were most commonly associated with atypical metastases. Pelvic metastases are more common with lower extremity primaries (accounting for 70% of cases with pelvic metastases) but 5% of patients with supraumbilical primaries also had pelvic metastases.

CONCLUSION: The distribution of metastatic melanoma in the abdomen and pelvis that we have defined should help guide the interpretation of CT exams in these patients.

FDG PET and PET/CT

Molecular imaging with positron emission tomography (PET) using tumour-seeking radiopharmaceuticals has gained wide acceptance in oncology with many clinical applications. The hybrid imaging modality PET/CT allows assessing molecular as well as morphologic information at the same time. Therefore, PET/CT represents an efficient tool for whole body staging and re-staging within one imaging modality. In oncology the glucose analogue (18)F-fluorodeoxyglucose (FDG) is the most widely used PET and PET/CT radiopharmaceutical in clinical routine. FDG PET and PET/CT have been used for staging and re-staging tumour patients in numerous studies. This chapter will discuss the use and the main indications of FDG PET and PET/CT in oncology with special emphasis on lung cancer, oesophageal cancer, colorectal cancer, head and neck cancer, lymphoma and breast cancer (among other tumour entities). A review of the current literature will be given with respect to primary diagnosis, staging and diagnosis of recurrent disease (local, lymph node and distant metastases). Besides its integral role in diagnosis, staging and re-staging of disease in oncology, there is increasing evidence that FDG PET and PET/CT can significantly contribute to therapy response assessment possibly influencing therapeutic management and treatment planning, to therapy tumour control and prediction of prognosis in oncologic patients, which will also be discussed in this chapter.

Cyclophosphamide promotes chronic inflammation-dependent immunosuppression and prevents antitumor response in melanoma

Low-dose cyclophosphamide (CP) therapy induces immunogenic tumor cell death and decreases regulatory T cell (Treg) numbers in mice with transplantable tumors. Using the ret transgenic murine melanoma model that resembles human melanoma, we detected no beneficial antitumor effects with such treatment, despite a decrease in Tregs. On the contrary, low-dose CP enhanced the production of chronic inflammatory mediators in melanoma lesions associated with increased accumulation of Gr1(+)CD11b(+) myeloid-derived suppressor cells (MDSCs), which exhibit elevated suppressive activity and nitric oxide (NO) production as well as inhibition of T-cell proliferation. Moreover, the frequencies of CD8(+) T cells in the tumors and their ability to produce perforin were decreased. To study whether the observed CP-induced MDSC expansion and activation also occurs under chronic inflammatory tumor-free conditions, mice exhibiting chronic inflammation were treated with CP. Similar to tumor-bearing mice, CP-treated inflamed mice displayed elevated levels of MDSCs with enhanced production of NO, reactive oxygen species, and a suppressed in vivo natural killer (NK) cell cytotoxic activity indicating CP effects on the host immune system independent of the tumor. We suggest that melanoma therapy with low-dose CP could be efficient only when combined with the neutralization of MDSC immunosuppressive function and chronic inflammatory microenvironment.

Novel biomarkers and therapeutic targets for optimizing the therapeutic management of melanomas

Cutaneous malignant melanoma is the most aggressive form of skin cancer with an extremely poor survival rate for the patients diagnosed with locally invasive and metastatic disease states. Intensive research has led in last few years to an improvement of the early detection and curative treatment of primary cutaneous melanomas that are confined to the skin by tumor surgical resection. However, locally advanced and disseminated melanomas are generally resistant to conventional treatments, including ionizing radiation, systemic chemotherapy, immunotherapy and/or adjuvant stem cell-based therapies, and result in the death of patients. The rapid progression of primary melanomas to locally invasive and/or metastatic disease states remains a major obstacle for an early effective diagnosis and a curative therapeutic intervention for melanoma patients. Importantly, recent advances in the melanoma research have led to the identification of different gene products that are often implicated in the malignant transformation of melanocytic cells into melanoma cells, including melanoma stem/progenitor cells, during melanoma initiation and progression to locally advanced and metastatic disease states. The frequent deregulated genes products encompass the oncogenic B-RafV600E and N-RasQ61R mutants, different receptor tyrosine kinases and developmental pathways such as epidermal growth factor receptor (EGFR), stem cell-like factor (SCF) receptor KIT, hedgehog, Wnt/β-catenin, Notch, stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor-4 (CXCR4) and vascular endothelial growth factor (VEGF)/VEGFR receptor. These growth factors can cooperate to activate distinct tumorigenic downstream signaling elements and epithelial-mesenchymal transition (EMT)-associated molecules, including phosphatidylinositol 3’-kinase (PI3K)/Akt/ molecular target of rapamycin (mTOR), nuclear factor-kappaB (NF-κB), macrophage inhibitory cytokine-1 (MIC-1), vimentin, snail and twist. Of therapeutic relevance, these deregulated signal transduction components constitute new potential biomarkers and therapeutic targets of great clinical interest for improving the efficacy of current diagnostic and prognostic methods and management of patients diagnosed with locally advanced, metastatic and/or relapsed melanomas.

Comparison between F-Fluorodeoxyglucose Positron Emission Tomography and Sentinel Lymph Node Biopsy for Regional Lymph Nodal Staging in Patients with Melanoma: A Review of the Literature

Aim. to compare ¹⁸F-Fluorodeoxyglucose positron emission tomography (FDG-PET) to sentinel lymph node biopsy (SLNB) for regional lymph nodal staging in patients with melanoma. Methods. We performed a literature review discussing original articles which compared FDG-PET to SLNB for regional lymph nodal staging in patients with melanoma. Results and Conclusions. There is consensus in the literature that FDG-PET cannot replace SLNB for regional lymph nodal staging in patients with melanoma.

Navigation-assisted localisation and resection of subclinical metastatic malignant melanoma of unknown primary based on 18-fluorodeoxyglcose positron emission tomography computed tomography fusion imaging

A technical application using a stereotactic navigation system with fusion images of [18F]-2-fluorodeoxyglucose (FDG) positron tomography and computed tomography (PET-CT) in the case of a metastatic melanoma of unknown primary site is described. A 50-year-old woman presented with a slow, growing level V neck lump which was cytologically proved to be a metastatic melanoma despite the absence of prior or existing history of skin malignancy. Whilst detailed physical examination failed to yield the site of the primary lesion, full body FDG-PET images isolated FDG-avid subclinical scalp lesions. Fused PET-CT data provided the navigation system with accurate localisation of the subclinical metastatic lesion. Histopathological examination of the navigation-guided resection specimen confirmed that the lesion was excised with acceptable margins. This case illustrates the feasibility of navigation-assisted resection of a subclinical malignant melanoma lesion and may have a role to play in the management of the melanoma of unknown primary.

Melanoma: epidemiology, diagnosis, treatment, and outcomes

Melanoma is a skin cancer that arises from the malignant transformation of melanocytes. Although it is typically considered a pigmented lesion, the clinical presentation of melanoma can vary greatly. With increased efforts in screening and detection of early-stage melanoma, researchers and clinicians hope to improve clinical outcomes for patients with melanoma. Novel immunotherapies directed at specific molecular targets in the pathogenesis of melanoma usher in a new era of treatment of advanced melanoma.