Metastatic melanomas of unknown primary show better prognosis than those of known primary: a systematic review and meta-analysis of observational studies

Good response of stage IV melanoma to high‑dose radiation therapy combined with immunotherapy: A case report

Patients with advanced malignant melanoma (MM) often do not receive satisfactory treatment. The present study reports the case of a 51-year-old female patient with stage IV MM of unknown primary. After undergoing immune checkpoint inhibitor therapy, the patient received multiple doses of hypofractionated radiotherapy (HFRT) for the left inguinal lymph node and single-fraction high-dose-rate brachytherapy for the left and right lung metastases. After combination treatment, the patient experienced almost complete remission of the inguinal target area, significant relief of pain and discomfort and an improved quality of life. The time of lung radiotherapy lesion control was 8 months. Meanwhile, the observed lesions (observation lesions 1, 2, 3 and 5) adjacent to the target lesion received lower doses of scattering (0.9-1.8 Gy) and the time of control for these lung observation lesions was 9 months. In addition, restarting targeted therapy after cessation of other treatments due to myelosuppression resulted in a progression-free survival time of 6 months. Nevertheless, the patient developed new metastases in the brain and abdomen. The present case report demonstrates that high-dose radiotherapy combined with immunotherapy may be effective for local lesions and that multiple doses of HFRT may be superior to single-fraction high-dose-rate brachytherapy for certain patients. Low-dose scattering also shows improvement for local lesions. Furthermore, restarting targeted therapy may be effective in the presence of target sites. Thus, the present case report provides a possible therapeutic option for the treatment of advanced melanoma.

Brief Communication: Treatment Outcomes for Advanced Melanoma of Unknown Primary Compared With Melanoma With Known Primary

SUMMARY

Most patients with advanced melanomas have a known primary site [melanoma of known primary (MKP)]. However, 2%-9% of patients are diagnosed with melanoma metastasis of unknown primary (MUP). As MUP and MKP have similar UV-induced mutations and molecular signatures, it is proposed that the primary tumor has regressed completely in patients with MUP. As regression of the primary tumor could be indicative of enhanced recognition of melanoma antigens, we hypothesize that patients with advanced MUP have a better outcome compared with MKP.Patients with advanced MUP from 10 German university hospitals were retrospectively analyzed and matched with MKP based on the type of systemic treatment (BRAF and MEK inhibitors, PD-1 inhibitor monotherapy, combined CTLA-4 and PD-1 inhibitor therapy) therapy line (first or second line) and AJCC stage (IIIC, IV M1a-M1d). Three hundred thirty-seven patients with MUP were identified, and 152 treatments with PD-1 and CTLA-4 inhibitors, 142 treatments with PD-1 inhibitors, and 101 treatments with BRAF and MEK inhibitors were evaluated. Median time to treatment failure was significantly prolonged in patients with MUP treated with PD-1 monotherapy (17 mo, 95% CI: 9-25, P = 0.002) compared with MKP (5 mo, 95% CI: 3.4-6.6), as well as in MUP treated with combined PD-1 and CTLA-4 therapy (11 mo, 95% CI: 4.5-17.5, P < 0.0001) compared with MKP (4 mo, 95% CI: 2.9-5.1) Occurrence of immune-related adverse events and time to treatment failure for patients with BRAF and MEK inhibitors was similar in MKP and MUP. In our multicentre collective, patients with MUP have better outcomes under immunotherapy compared with MKP.

Comprehensive Literature Review on Melanoma of Unknown Primary Site Triggered by an Intriguing Case Report

Melanoma is one of the most aggressive forms of skin cancer. While most melanomas have a discernible primary site, a small subset, approximately 3.2%, present as a metastatic disease without an identifiable primary origin, a condition known as melanoma of unknown primary (MUP). Unusual cases of primary melanoma have also been previously reported in the respiratory, gastrointestinal, and urogenital tracts. MUP typically is found in lymph nodes, subcutaneous sites, and visceral organs, with hypotheses about its origin including spontaneous primary tumor regression and ectopic melanocytes. MUP presents unique challenges in diagnosis and treatment due to the absence of a detectable primary tumor. Understanding its genetic and molecular features, epidemiology, prognostic factors, and treatment options is crucial for optimizing patient care and outcomes in this subset of melanoma patients. We conducted an extensive literature review triggered by a case report of a patient with suspected MUP. A 51-year-old woman was transferred from another hospital where an incision was performed for a suspected superinfected hematoma of the left thigh. Since the patient showed high leukocytosis and redness and swelling of the thigh, local debridement, drainage, and excisional biopsy of the tumor mass were performed in our unit in the emergency setting, and the tumor was taken for histopathology evaluation. Intraoperatively, the mass appeared nonspecific. The permanent histopathology report established a diagnosis of melanoma, with tumor proliferation also involving lymphoid tissue, and despite broad clinical and imagistic assessments, the primary melanoma could not be identified. Clinicians must be aware of the varied clinical manifestations of malignant melanoma, especially in cases of occult melanoma where the primary site is not evident.

Malignant melanoma in Portuguese adult population: a scoping review of the real-world evidence

PURPOSE

Malignant melanoma is an aggressive cancer, and there is a notable dearth on epidemiology, clinical and treatment characterization within the Portuguese population. We performed a scoping review to identify real-world evidence studies focused in Portuguese adult patients with malignant melanoma.

METHODS

A comprehensive search was conducted. After screening, we described the studies by design, sample size, geographics, setting, population, and outcomes reported.

RESULTS

The search yielded 54 studies, mainly retrospective (79.6%). The population assessed was heterogeneous varying from patients with melanoma in general to specific types of melanoma, or even more restricted to patients with specific conditions. The evidence found was mostly concerning clinical outcomes (n=46), patients' clinical profile (n=44) and demographic characterization (n=48). Treatment information was described in 30 studies whereas only 18 reported epidemiological parameters. Studies were mainly performed by the major oncology centers in Lisbon, Oporto and Coimbra, and only two evaluated the entire Portuguese population. To allow comparability, only studies including patients with cutaneous malignant melanoma were considered (13 of the 54) for outcomes evaluation analysis. Median OS varied from 18 to 36 months, assessed after melanoma treatment. Incidence was the most reported epidemiological parameter, confirming the increasing number of cutaneous malignant melanoma patients over the years. Only one study reported prevalence and four reported mortality rates.

CONCLUSIONS

The evidence found confirms the lack of information about malignant melanoma in Portugal, highlighting the need of real-world studies to assess melanoma prevalence and incidence rates, current treatment approaches, and clinical characterization of these patients.

Characteristics of long-survivor metastatic melanoma after polychemotherapy and interferon: a retrospective study

BACKGROUND

The development of immunotherapy and tyrosine kinase inhibitors dramatically improved the prognosis of metastatic melanoma. Consequently, chemotherapy is now rarely used. Here, we describe the characteristics of long-surviving patients with metastatic melanoma treated with immunochemotherapy.

MATERIAL AND METHODS

We retrieved retrospective clinical and pathological data for patients diagnosed with metastatic melanoma between January 1993 and December 2015 who received the CVD-INF (cisplatin, vinblastine, dacarbazine, and interferon α-2b) regimen at the Hôpitaux Universitaires de Genève. We estimated their progression-free survival and overall survival. This ad hoc study's primary aim was to describe the clinical and biological characteristics of long-term survivors, defined as patients surviving more than two years after immunochemotherapy initiation. The spatial distribution pattern of CD8+ T cells (inflamed, excluded, or desert) was immunohistochemically determined.

RESULTS

Ninety patients received CVD-INF. Their median age at metastatic melanoma diagnosis was 55 years (20-75). Their median progression-free survival was 2.8 months, and median overall survival was 7.2 months. Eleven (12%) patients were long-term survivors. In multivariate analysis, central nervous system metastases (hazard ratio [HR]: 2.66; 95% confidence interval [CI]: 1.43-4.95; p = 0.001), multiple metastases (HR: 1.82; 95% CI: 1.01-3.29; p = 0.047), and elevated lactate dehydrogenase (LDH) (HR: 1.92; 95% CI: 1.12-3.30; p = 0.016) were independently associated with shorter survival. Most long-survivors (6/8; 75%) had a tumour-inflamed pattern compared to 25% of non-long survivors (5/20; Fisher's test p = 0.030).

CONCLUSIONS

A subset of patients with metastatic melanoma and a tumour-inflamed phenotype treated with CVD-INF survived over two years. Factors associated with prolonged survival are consistent with those previously reported in metastatic melanoma.

Report on a case of liver-originating malignant melanoma of unknown primary

Malignant melanoma (MM) frequently occurs in the skin or mucosa, whereas malignant melanoma of unknown primary (MUP) is diagnosed in patients with lymph nodes or visceral organs as the site of origin, where it is challenging to detect the primary lesion by comprehensive examination. MUP is possibly related to the spontaneous regression of the primary lesion. In addition, primary hepatic melanoma (PHM) usually refers to the primary MM occurring in the liver, with no typical primary lesions and no manifestations of tumor metastasis. A 61-year-old male patient with liver as the site of origin was diagnosed with MM by Melan-A, HMB-45, and S-100 immunohistochemistry staining of liver biopsy tissue. Based on a comprehensive examination, no basis was found for melanoma in sites such as the skin, mucosa, five sense organs, brain, digestive tract, respiratory tract, or genitalia, and the patient was subsequently diagnosed with MUP. MMs require a comprehensive inspection, beginning with the liver, to search for the primary lesion; if the primary lesion is not found, the possibility of PHM or MUP should be considered.

A patient with rapidly growing axillary masses

ABSTRACT

About 85,000 melanomas are diagnosed every year in the United States, but only about 3.2% are diagnosed without a primary site. This article describes a patient who presented with two rapidly growing axillary masses and was found to have metastatic melanoma of the lymph nodes with no known primary site. Melanoma of unknown primary (MUP) site is staged either III or IV level. Management is determined in the same manner as stage-matched melanoma of known primary site.

Brain metastases in adult patients with melanoma of unknown primary in the Netherlands (2011-2020)

BACKGROUND

Although patients with melanoma of unknown primary (MUP) have a better prognosis than similar-staged melanoma patients with known primary, the occurrence of brain metastases (BM) entails a serious complication. This study provides an overview of the incidence, treatment patterns, and overall survival (OS) of adult patients with BM-MUP in the Netherlands.

METHODS

BM-MUP cases were retrieved from the Netherlands Cancer Registry. Patient, disease and treatment-related characteristics were summarised using descriptive statistics. Overall survival (OS) was calculated by the Kaplan-Meier method, and the impact of prognostic factors on OS was assessed using Cox proportional hazard regression analyses.

RESULTS

Among 1779 MUP patients, 450 were identified as BM-MUP (25.3%). Of these patients, 381 (84.7%) presented with BM along with other metastases, while 69 (15.3%) had BM only. BM-MUP patients were predominantly male (68.2%), and had a median age of 64 years at diagnosis (interquartile range 54-71 years). Over time, the proportion of BM along other metastatic sites increased, and the occurrence of BM decreased (p = 0.01). 1-Year OS improved for the total population, from 30.0% (95% confidence interval (CI): 19.8-40.9%) in 2011-2012 to 43.6% (95%CI: 34.5-52.3%) in 2019-2020, and median OS more than doubled from 4.2 months (95%CI: 3.3-6.2 months) to 9.8 months (95%CI: 7.0-13.2 months). Patient's age, localisation of BM, presence of synchronous liver metastasis and treatment were identified as independent predictors of OS.

CONCLUSION

Notwithstanding the progress made in OS for patients with BM-MUP in the past decade, their overall prognosis remains poor, and further efforts are needed to improve outcomes.

Impact of systemic therapies in metastatic melanoma of unknown primary: A study from MELBASE, a French multicentric prospective cohort

BACKGROUND

Clinical outcomes of advanced melanoma of unknown primary (MUP) in the era of novel therapies have been scarcely studied.

OBJECTIVE

To investigate the efficacy and safety of systemic treatments in patients with advanced MUP compared to patients with stage-matched melanoma of known cutaneous primary (cMKP).

METHODS

Based on the nationwide MelBase prospective database, this study included advanced melanoma patients treated from March 2013 to June 2021 with first-line immunotherapies, targeted therapies, or chemotherapy. Co-primary outcomes were progression-free survival and overall survival. Secondary outcome was treatment-related toxicities. Multivariate and propensity score analyses were performed.

RESULTS

Of 1882 patients, 265 (14.1%) had advanced MUP. Patients with advanced MUP displayed more often unfavorable initial prognostic factors than those with cMKP. Progression-free and overall survival did not differ significantly between the groups (P = .73 and P = .93, respectively), as well as treatment-related toxicity rate and severity, regardless of treatment type.

LIMITATIONS

No record of standard diagnostic criteria of MUP used in the participating centers.

CONCLUSIONS

Although patients with MUP had less favorable baseline prognostic factors, they benefited from the novel therapies as much as those with cMKP. They should be managed according to similar strategies.

Proton beam therapy for cervical lymph node metastasis in an octogenarian with melanoma of unknown primary: a case report

An 80-year-old man with an approximately 3-cm mass in the right submandibular region presented to our institution. Magnetic resonance imaging revealed enlarged lymph nodes (LNs) in the right neck, and fluorine-18-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) indicated positive FDG accumulation in the right neck LNs only. Excisional biopsy was performed for suspected malignant lymphoma, and the biopsy revealed melanoma. Close examination of the skin, nasal cavity, oral pharyngeal and laryngeal cavities, and gastrointestinal tract were performed. No primary tumor was detected by these examinations, and the patient was diagnosed with cervical LN metastasis from melanoma of unknown primary of clinical stage T0N3bM0 stage IIIC. The patient refused cervical neck dissection because of his age and comorbidity of Alzheimer's disease and instead opted for proton beam therapy (PBT) at a total dose of 69 Gy (relative biological effectiveness) in 23 fractions. He did not receive any systemic therapy. The enlarged LNs shrunk slowly, and FDG PET/CT at 1 year after PBT showed that the right submandibular LN had shrunk from 27 to 7 mm in length, and there was no significant FDG accumulation. At 6 years and 4 months after PBT, the patient is alive without any recurrence.

Melanoma of unknown primary origin with skeletal muscle metastasis: a case report

BACKGROUND

Melanoma is usually discovered from an irregular skin patch or a modification of a preexisting patch. Cutaneous and lymph node metastases are common. Muscle metastases are rare. We report a case of melanoma with infiltration of the gluteus maximus, which had normal dermatological examination.

CASE PRESENTATION

A 43-year-old Malagasy man with no history of skin surgery was admitted with progressively worsening dyspnea. On admission, he presented with superior vena cava syndrome, painless cervical lymphadenopathy, and a painful swelling in the right buttock. Skin and mucous membrane examination did not reveal any abnormal or suspicious lesions. The biology was limited to a C-reactive protein of 40 mg/L, a white blood cell count of 23 G/L, and a lactate dehydrogenase level of 1705 U/L. The computed tomography scan showed several lymphadenopathies, compression of the superior vena cava, and a tissue mass at the expense of the gluteus maximus. Cervical lymph node biopsy and cytopuncture of the gluteus maximus were consistent with a secondary melanoma location. A stage IV melanoma of unknown primary origin, and with stage TxN3M1c associated with lymph node metastases and extension to the right gluteus maximus, was suggested.

CONCLUSIONS

Melanoma of unknown primary origin accounts for 3% of diagnosed melanomas. Diagnosis is difficult in the absence of a skin lesion. Patients are diagnosed with multiple metastases. Muscle involvement is unusual and may suggest a benign pathology. In this context, biopsy remains essential for diagnosis.

Survival after lymphadenectomy of nodal metastases from melanoma of unknown primary site

Although the vast majority of melanomas have a primary site, 3%-4% of all melanomas in distant sites display no known primary site (MUP). This phenomenon is not fully understood and various hypotheses have been introduced. The prognostic significance of MUP has been unclear, with some studies showing no survival benefit while others find improved survival compared to stage-matched patients with melanoma of known primary site (MKP). Between 1997 and 2014, 864 patients underwent an en bloc resection of clinical nodal metastases at a referral centre for metastatic melanoma in Norway. The MUP (n = 113) and MKP (n = 751) patients were graded with stage III or IV. The overall survival (OS) was calculated with the Kaplan-Meier method, and multivariate analysis identified factors of significance for the two groups. A significant five-year OS emerged for stage III, MUP = 58% and 42% for MKP, but not for stage IV. The five-year relapse-free survival (RFS) was 41% and 31% for MUP and MKP respectively (p = 0.049). The statistically significant inter-group differences (MUP/MKP) were observed in the univariate and multivariate analyses of age, gender, number of affected nodes, tumour size and perinodal growth within stage III and tumour size within stage IV. After regional lymphadenectomy, MUP patients with clinical nodal metastases had a better outcome than MKP patients. This finding supports the theory that an endogenously mediated immune response may promote the regression of a cutaneous melanoma.

A rare case of endobronchial melanoma of unknown primary

A 62-year-old man who presented with complaints of cough and hemoptysis was found to have an endobronchial tumor which obstructed the lingular bronchus. Histopathologic examination of a bronchoscopic biopsy of the tumor was consistent with malignant melanoma. Skin, mucosal, and eye examinations failed to detect the primary site of melanoma and the patient was diagnosed with endobronchial melanoma of unknown primary (MUP). Although the patient underwent a curative surgical resection, recurrence was detected in 4 months. Endobronchial MUP is a rare presentation of melanoma and better therapeutic strategies need to be established.

Treatment of Metastatic Melanoma at First Diagnosis: Review of the Literature

Metastatic melanoma (MM) is a pathological entity with a very poor prognosis that, until a few decades ago, had a low response rate to systemic treatments. Fortunately, in the last few years, new therapies for metastatic melanoma have emerged. Currently, targeted therapy and immunotherapy are the mainstays of the therapeutic arsenal available for patients with unresectable or metastatic melanoma. However, both clinical evolution and drug efficacy in melanoma patients are very different depending on the stage at which it is diagnosed. In fact, the aggressiveness of melanoma is different depending on whether it debuts directly as metastatic disease or if what occurs is a relapse after a first diagnosis at an early stage, although the biological determinants are largely unknown. Another key aspect in the clinical management of metastatic melanoma at first diagnosis strives in the different prognosis of melanoma of unknown primary (MUP) compared to melanoma of known primary (MPK). Understanding the mechanisms behind this, and the repercussion of implementing targeted and immune therapies in this specific form is crucial for designing diagnosis and treatment decision algorithms that optimize the current strategies. In this review article, we recapitulate the information available thus far regarding the epidemiology and response to immunotherapy treatments or targeted therapy in patients diagnosed with metastatic melanoma as a first diagnosis, with especial emphasis on the emerging specific information of the subpopulation formed by MUP patients.

Emergent immunotherapy approaches for brain metastases

Brain metastases from solid tumors are increasing in incidence, especially as outcomes of systemic therapies continue to extend patients’ overall survival. The long-held notion that the brain is an immune sanctuary has now been largely refuted with increasing evidence that immunotherapy can induce durable responses in brain metastases. Single agent immune checkpoint inhibition with anti-CTLA4 and anti-PD1 antibodies induces durable responses in 15%–20% in melanoma brain metastases as long as patients are asymptomatic and do not require corticosteroids. The combination of anti-CTLA4 with anti-PD-1 antibodies induces an intracranial response in over 50% of asymptomatic melanoma patients, and much lower rate of otherwise durable responses (20%) in symptomatic patients or those on steroids. Data in other cancers, such as renal cell carcinoma, are accumulating indicating a role for immunotherapy. Emerging immunotherapy approaches will have to focus on increasing response rates, decreasing toxicity, and decreasing steroid dependency. The path to those advances will have to include a better understanding of the mechanisms of response and resistance to immunotherapy in brain metastases, the use of novel agents such as anti-LAG3 checkpoint inhibitors, targeted therapy (oncogene directed or TKIs), and possibly surgery and SRS to improve the outcomes of patients with brain metastases.

Disseminated Bone Marrow Carcinomatosis Due to Malignant Melanoma of Unknown Primary Origin

An 80-year-old woman was admitted to our hospital due to appetite loss and vomiting. A blood examination showed liver disorder with disseminated intravascular coagulation. All tumor markers and hepatitis virus markers were negative. Contrast-enhanced computed tomography did not show tumor lesions, bone lesions, lymphadenopathies, or thrombosis. A bone marrow biopsy revealed large, atypical cells with brown pigmentation and positive immunostaining for HMB-45, S100 proteins, and CD79a without myeloid or lymphoid markers. We experienced a case of disseminated carcinomatosis of the bone marrow due to malignant melanoma of unknown primary origin.

Thoracic metastasis of malignant melanoma of unknown primary: A case report and literature review

INTRODUCTION

Metastatic melanoma of unknown primary (MUP) is an unusual entity found in distant sites without evident skin lesion. We report a case of 45-year-old woman who underwent monobloc resection of a metastatic thoracic malignant melanoma of unknown primary, and who is currently under immunotherapy without local or distant recurrence during a follow-up of 18 months. We demonstrate through this case that R0 resection of an MUP associated with immunotherapy improves the prognosis and survival in these patients.

CASE REPORT

This is a 45-year-old woman who underwent monobloc resection of a mass carrying the anterior arch of the second left rib associated with a wedge resection of a nodule at the left upper lobe. Histology confirmed that it was a malignant melanoma. Her history was negative for melanocytic lesions, physical examination and imaging had failed to identify a primary lesion. The patient is currently under nivolumab for Stage IV melanoma and does not present any complications or recurrence during the long term follow up.

DISCUSSION

Metastatic melanoma of unknown primary (MUP) is a melanocytic lesion in distant sites in the absence of apparent skin involvement and is rare, accounting for 3, 2% of all incident melanomas as well as being yet poorly understood in terms of pathogenesis (Bae et al., 2015) [1]. MUP is clinically understudied, investigators to date have reported largely on the use of localized treatment for MUP (surgery or radiotherapy), while the efficacy of systemic therapy in MUP patients remains unexplored. Clinical trials of immunotherapy and targeted therapy in patients with advanced cutaneous melanoma have not explicitly reported response rates specific to MUP patient subgroups due to its low incidence and lack of annotation. MUP's response to these now FDA-approved therapies could add to the discussion of MUP's elusive biological characteristics, as well as aid in making clinical recommendations (Utter et al., 2017).

CONCLUSION

Metastatic MUP is an extremely rare entity which is still poorly understood, few cases are described in the literature, its treatment remains controversial and there are no specific treatment recommendations for patients with MUP. Several authors recommend local treatment when possible and tend to apply similar strategies for patients with paired stage primary known melanoma (PKM).

Biomarkers of Targeted Therapy and Immuno-Oncology in Cancers Metastatic to the Breast

The breast is a rare site for metastases, and their molecular characteristics have not been studied yet. Intrinsic molecular genetics, cancer characteristics, and breast tissue immune responses in diverse metastases to the breast have not been previously studied. We identified 64 patients with cancers metastatic to the breast: 51 carcinomas and 13 melanomas. Programmed death ligand 1 (PD-L1), steroid receptors, and HER2/neu expressions were evaluated using immunohistochemistry. Gene sequencing, copy number alterations, microsatellite instability, and tumor mutational burden were performed using next-generation sequencing platforms. The 3 most common primary sites for metastatic carcinomas were lung (37%), ovary (29%), and fallopian tubes/peritoneum (14%). TP53 mutations were commonly (50%) observed among the carcinoma cases, while other mutations were characteristic for the primary cancers (VHL in renal, BRCA1 in the fallopian tube, and BRAF in melanomas). High tumor mutational burden was detected in 5/14 carcinomas and 3/7 melanomas. Tumor cell PD-L1 expression was detected in 6 carcinomas, but not in any of the melanomas, whereas immune cells' expression of PD-L1 was seen in 17 carcinomas and 6 melanomas. Estrogen receptor status was positive in 13/49 carcinomas including 12 adenocarcinomas originating from the ovary and fallopian tube or peritoneum and 1 duodenal neuroendocrine carcinoma. No carcinoma was HER2/neu positive. Intrinsic genetic characteristics of the metastases to the breast followed the pattern commonly seen in primary tumors. Biomarkers of potential benefit to immune checkpoint inhibition therapy were limited to PD-L1-positive non-small cell lung cancer. No common characteristics of the heterogeneous group of tumor metastases to this organ were identified.

Outcomes after retreatment with MAPK inhibitors and immune checkpoint inhibitors in melanoma patients

Background: When patients with advanced melanoma progress after MAPK inhibitor (MAPKI) and immune checkpoint inhibitor (ICI) treatment, they can either undergo chemotherapy or rechallenge with previously used treatments. Methods: The outcomes of 48 patients retreated with MAPKIs and 50 patients retreated with ICIs following progression were retrospectively analyzed. Results: Upon retreatment with MAPKIs, the disease control rate was 60%. Univariate analysis of possible risk factors associated with short progression-free survival upon MAPKI treatment showed elevated lactate dehydrogenase to be associated with decreased progression-free survival. Disease control rate after ICI retreatment was 24%. Melanoma of unknown primary was associated with prolonged progression-free survival upon ICI retreatment. Conclusion: Retreatment with MAPKIs or ICIs is a feasible option for patients with advanced melanoma.

Comparative genomic characterization of melanoma of known and unknown primary

BACKGROUND

This study aims to genomically characterize melanoma of unknown primary (MUP) in comparison to melanomas of cutaneous primary (MCP).

METHODS

Eligible cases were collected from the MSK-IMPACT™ Clinical Sequencing Cohort published in the cBioPortal database. Genomic analysis was performed using a hybridization-capture-based next-generation sequencing assay designed to detect mutations, small insertions and deletions, copy number alterations, and genomic rearrangements.

RESULTS

Among 462 patients of whom 18.4% had MUP, brain metastasis was more common among patients with MUP (23% vs 7.1%). The differences in genomic profiling between MCP and MUP did not reach statistical significance. The 187 MCP and 44 MUP patients treated with immune checkpoint inhibitors had a median overall survival of 49 and 44 months, respectively (p = 0.705).

CONCLUSIONS

The differences in somatic mutation patterns and survival outcomes were not statistically significant. These findings may allude to similar carcinogenic processes but should be considered exploratory and interpreted with caution.

Combined immune checkpoint inhibitors of CTLA4 and PD-1 for hepatic melanoma of unknown primary origin: A case report

BACKGROUND

Melanoma is uncommonly found in lymph nodes, subcutaneous tissue, or visceral organs without a primary lesion, where it is identified as metastatic melanoma with unknown primary (MUP). Hepatic MUP is extremely rare and has a poor prognosis. There is limited information on its pathogenesis, clinical and imaging features, and pathological findings. There are no guidelines for the use of immune checkpoint inhibitors (ICIs) in hepatic MUP, and the treatment outcome has rarely been reported.

CASE SUMMARY

A 42-year-old woman presented to our hospital with hepatic tumors found incidentally during a routine check-up. Contrast-enhanced abdominal com-puterized tomography showed multiple mass lesions in the liver. Pathological results revealed melanoma, which was confirmed by immunohistochemical staining for HMB-45(+), Melan-A(+), S-100(+), and SOX10(+). There was no evidence of primary cutaneous, ocular, gastrointestinal, or anal lesion on a comprehensive examination. The patient was diagnosed with hepatic MUP. She received combined antibodies against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4, ipilimumab) and programmed death protein-1 (PD-1, nivolumab). She died of hepatic failure 9 mo after hepatic MUP was diagnosed. This the first case of hepatic MUP treated with combined ipilimumab and nivolumab, who showed better outcome than previous cases.

CONCLUSION

Combined ICIs of PD-1 and CTLA-4 may be considered as the first-line therapy for patients with hepatic MUP.

Clinical outcome of patients with metastatic melanoma of unknown primary in the era of novel therapy

Melanoma of unknown primary (MUP) is considered different from melanoma of known primary (MKP), and it is unclear whether these patients benefit equally from novel therapies. In the current study, characteristics and overall survival (OS) of patients with advanced and metastatic MUP and MKP were compared in the era of novel therapy. Patients were selected from the prospective nation-wide Dutch Melanoma Treatment Registry (DMTR). The following criteria were applied: diagnosis of stage IIIc unresectable or IV cutaneous MKP (cMKP) or MUP between July 2012 and July 2017 and treatment with immune checkpoint inhibition and/or targeted therapy. OS was estimated using the Kaplan–Meier method. The stratified multivariable Cox regression model was used for adjusted analysis. A total of 2706 patients were eligible including 2321 (85.8%) patients with cMKP and 385 (14.2%) with MUP. In comparative analysis, MUP patients more often presented with advanced and metastatic disease at primary diagnosis with poorer performance status, higher LDH, and central nervous system metastases. In crude analysis, median OS of cMKP or MUP patients was 12 months (interquartile range [IQR] 5 – 44) and 14 months (IQR 5 – not reached), respectively (P = 0.278). In adjusted analysis, OS in MUP patients was superior (hazard rate 0.70, 95% confidence interval 0.58–0.85; P < 0.001). As compared to patients with advanced and metastatic cMKP, MUP patients have superior survival in adjusted analysis, but usually present with poorer prognostic characteristics. In crude analysis, OS was comparable indicating that patients with MUP benefit at least equally from treatment with novel therapies.

Melanoma of Unknown Primary: Evaluation of the Characteristics, Treatment Strategies, Prognostic Factors in a Monocentric Retrospective Study

BACKGROUND

Melanoma of unknown primary (MUP), accounts for up to 3% of all melanomas and consists of a histologically confirmed melanoma metastasis to either lymph nodes, (sub)cutaneous tissue, or visceral sites without any evidence of a primary cutaneous, ocular, or mucosal melanoma. This study aimed to investigate the characteristics, treatment strategies, and prognostic factors of MUP patients, in order to shed some light on the clinical behavior of this malignancy.

METHODS

All the consecutive patients with a diagnosis of MUP referring to our institutions between 1985 and 2018 were considered in this retrospective cohort study. The records of 173 patients with a suspected diagnosis of MUP were retrospectively evaluated for inclusion in the study. Patient selection was performed according to the Das Gupta criteria, and a total of 127 MUP patients were finally included in the study, representing 2.7% of the patients diagnosed with melanoma skin cancer at our institutions during the same study period. A second cohort of all consecutive 417 MKP patients with AJCC stages IIIB-IV, referring tions in the period considered (1985-2018), was included in the study to compare survival between MUP and MKP patients. All the diagnoses were based on histopathologic, cytologic and immunohistochemical examination of the metastases. All tumors were re-staged according to the 2018 American Joint Committee on Cancer (AJCC) 8th Edition.

RESULTS

Median follow-up was 32 months (IQR: 15-84). 3-year progression-free survival (PFS) was 54%, while 3-year overall survival (OS) was 62%. Worse OS and PFS were associated with older age (P = 0.0001 for OS; P = 0.008 for PFS), stage IV (P < 0.0001 for OS; P = 0.0001 for PFS) and higher Charlson Comorbidity Index (P < 0.0001 for OS and P = 0.01 for PFS). Patients with lymph node disease showed longer PFS (P = 0.001) and OS (P = 0.0008) than those with (sub)cutis disease. Complete lymph node dissection (CLND) was the most common surgical treatment; a worse OS in these patients was associated with the number of positive lymph nodes (P = 0.01), without significant association with the number of retrieved lymph nodes (P = 0.79). Survival rates were lower in patients undergoing chemotherapy (CT) and target therapy (TT), and higher in those receiving immunotherapy (IT). 417 patients with AJCC stages IIIB-IV of Melanoma Known Primary (MKP) were included for the survival comparison with MUP. 3-year PFS rates were 54 and 58% in MUP and MKP, respectively (P = 0.30); 3-year OS rates were 62 and 70% in MUP and MKP, respectively (P = 0.40).

CONCLUSIONS

The most common clinical scenario of our series was a male patient around 59 years with lymph node disease. We report that CLND associated with IT was the best treatment in terms of survival outcome. In the current era of IT and TT for melanoma, new studies have to clarify the impact of novel drugs on MUP.

Metastatic melanoma of the spleen without known primary

We present the case of a patient who underwent a laparoscopic splenectomy for splenomegaly associated with anemia and thrombocytopenia thought to be secondary to lymphoma and was found to have metastatic melanoma without a primary source. This is a rare entity in that the patient falls into an atypical population group with conflicting opinions about management that has been scarcely reported in the literature.

Multidisciplinary Care for Melanoma of Unknown Primary: Experience in the Era of Molecular Profiling

BACKGROUND

Melanoma of unknown primary (MUP) accounts for approximately 3% of melanoma diagnoses. This study sought to evaluate treatment and outcomes for a modern MUP cohort.

METHODS

A retrospective review of MUP was performed at a tertiary referral cancer center.

RESULTS

Of 815 melanoma patients, 67 (8.2%) had MUP. Men were more likely to have MUP than women (67% vs. 55%; p = 0.04). The most common sites of MUP were lymph nodes (28%), visceral solid organs (25%), brain (16%), and skin/subcutaneous tissues (10%). Of the patients who underwent tumor genomic profiling, 52% harbored pathogenic BRAF mutations. Of the 24 patients who underwent multi-gene panel testing, all had pathogenic mutations and 21 (88%) had mutations in addition to or exclusive of BRAF, including 11 patients (46%) with telomerase reverse transcriptase promoter mutations. Checkpoint inhibitors (39%) and BRAF-MEK inhibitors (7%) were the most common first-line treatments. Upfront surgical resection was used for 25% of the MUP patients, and 12 of these resections were for curative intent. During a median follow-up period of 22.1 months, the median overall survival (OS) was not met for the patients with MUP isolated to lymph nodes. At 56.8 months, 75% of these patients were alive. The median OS was 37.4 months for skin/soft tissue MUP, 33.3 months for single solid organ viscera MUP, and 29.8 months for metastatic brain MUP.

CONCLUSION

Multigene panel testing identified pathogenic mutations in all tested MUP patients and frequently identified targets outside BRAF. Despite advanced stage, aggressive multimodal therapy for MUP can be associated with 5-year OS and should be pursued for appropriate candidates.

Uncommon Subtypes of Malignant Melanomas: A Review Based on Clinical and Molecular Perspectives

Malignant melanoma represents the most aggressive type of skin cancer. Modern therapies, including targeted agents and immune checkpoint inhibitors, have changed the dismal prognosis that characterized this disease. However, most evidence was obtained by studying patients with frequent subtypes of cutaneous melanoma (CM). Consequently, there is an emerging need to understand the molecular basis and treatment approaches for unusual melanoma subtypes. Even a standardized definition of infrequent or rare melanoma is not clearly established. For that reason, we reviewed this challenging topic considering clinical and molecular perspectives, including uncommon CMs-not associated with classical V600E/K BRAF mutations-malignant mucosal and uveal melanomas, and some unusual independent entities, such as amelanotic, desmoplastic, or spitzoid melanomas. Finally, we collected information regarding melanomas from non-traditional primary sites, which emerge from locations as unique as meninges, dermis, lymph nodes, the esophagus, and breasts. The aim of this review is to summarize and highlight the main scientific evidence regarding rare melanomas, with a particular focus on treatment perspectives.

Patients with melanoma of unknown primary show better outcome under immune checkpoint inhibitor therapy than patients with known primary: preliminary results

Background: Melanoma of unknown primary (MUP) is an uncommon clinical subtype of melanoma of known primary (MKP). Objectives: We aimed to compare treatment outcomes of MUP and MKP patients who had undergone therapy with immune checkpoint inhibitors (ICPI). Methods: We studied 41 metastatic melanoma patients (32 with MKP and 9 with MUP) with an indication for ICPI. Results: Clinical characteristics such as age, gender, stage of disease, etc., did not significantly differ (P < .05) between MUP and MKP patients. 20/32 (62.5%) melanoma-specific deaths (MSD) were observed in the MKP group, whereas 2/9 (22.2%) were detected in the MUP group (P = .035). On logistic regression, the MUP status proved to be an independent predictor for a more favorable outcome under immunotherapy when compared to MKP (P = .030). Conclusion: Our preliminary results indicate that MUP patients show better clinical outcome under ICPI when compared to MKP.

Survival Outcomes of Patients with Clinical Stage III Melanoma in the Era of Novel Systemic Therapies

BACKGROUND

Immune checkpoint and BRAF-targeted inhibitors have demonstrated significant survival benefits for advanced melanoma patients within the context of clinical trials. We sought to determine their impact on overall survival (OS) at a population level in order to better understand the current landscape for patients diagnosed with clinical stage III melanoma.

METHODS

A retrospective study was performed using the National Cancer Database. Patients diagnosed with clinical stage III melanoma were categorized by diagnosis year into two cohorts preceding the advent of novel therapies (P1: 2004-2005, P2: 2008-2009) and a contemporary group (P3: 2012-2013). OS was estimated using standard time-to-event statistical methods.

RESULTS

Of 3720 patients, 525 (14%) were diagnosed in P1, 1375 (37%) in P2, and 1820 (49%) in P3. Median age at diagnosis increased over time (58, 59, and 61 years in P1, P2, and P3, respectively, P = 0.004). OS increased between P2 (median 49.3 months) and P3 (median 58.2 months, Bonferroni-corrected log-rank P < 0.001) but did not differ between P1 (median 50.5 months) and P2 (Bonferroni-corrected log-rank P > 0.99). These differences persisted on multivariable analysis. OS improved for patients diagnosed in P3 compared with P1 [hazard ratio (HR) 0.76, P < 0.001] but not P2 compared with P1 (HR 0.96, P = 0.52).

CONCLUSIONS

OS has significantly improved nationally for patients newly diagnosed with clinical stage III melanoma in the era of novel melanoma therapies. OS outcomes will likely continue to evolve as these agents are increasingly utilized in the adjuvant setting. These data may help to better inform affected patients with respect to prognosis.

Treatment of melanoma of unknown primary in the era of immunotherapy and targeted therapy: A Dutch population-based study

Melanoma of unknown primary (MUP) may have a different biology to melanoma of known primary, but clinical trials of novel therapies (e.g., immune checkpoint or BRAF/MEK inhibitors) have not reported the outcomes in this population. We therefore evaluated the overall survival (OS) among patients with MUP in the era of novel therapy. Data for stage III or IV MUP were extracted from a nationwide database for the period 2003–2016, with classification based on the eighth edition of the American Joint Committee on Cancer criteria. The population was divided into pre‐ (2003–2010) and post‐ (2011–2016) novel therapy eras. Also, OS in the post‐novel era was compared between patients with stage IV MUP by whether they received novel therapy. In total, 2028 of 65,110 patients (3.1%) were diagnosed with MUP. Metastatic sites were known in 1919 of 2028 patients, and most had stage IV disease (53.8%). For patients with stage III MUP, the 5‐year OS rates were 48.5% and 50.2% in the pre‐ and post‐novel eras, respectively (p = 0.948). For those with stage IV MUP, the median OS durations were unchanged in the pre‐novel era and post‐novel era when novel therapy was not used (both 4 months); however, OS improved to 11 months when novel therapy was used in the post‐novel era (p < 0.001). In conclusion, more than half of the patients with MUP are diagnosed with stage IV and the introduction of novel therapy appears to have significantly improved the OS of these patients.

What's new?

Melanoma of unknown primary (MUP) site may have a different biology to melanoma of known primary, but clinical trials of novel therapies (e.g., immune checkpoint or BRAF/MEK inhibitors) have not reported the outcomes in this population. Knowledge about outcomes could however aid clinical management of patients with MUP. In this nationwide study from 2003 to 2016, the authors show that the introduction of novel therapy has significantly improved the overall survival for patients with stage IV melanoma of unknown primary, who represented more than half of the patients diagnosed with MUP in the Netherlands.

Melanom

Das Melanom ist der gefährlichste Hautkrebs mit der höchsten Sterblichkeitsrate, der schon bei jungen Menschen auftreten kann und seit Jahrzehnten steigende Inzidenz verzeichnet (Jemal et al. 2007; Little et al. 2012). Jährlich erkranken weltweit etwa 137.000 Menschen am Melanom und 37.000 versterben an der Erkrankung (Boyle et al. 2004). Die Inzidenz liegt weltweit jährlich bei 2,3–2,6/100.000 Einwohner (Pisani et al. 2002). In Deutschland beträgt die Inzidenz 19,2/100.000 Einwohner und es verstarben 2711 Betroffene im Jahre 2010 (Statistisches Bundesamt).

Brain metastases as first manifestation of advanced cancer: exploratory analysis of 459 patients at a tertiary care center

Symptomatic brain metastases (BM) are a frequent and late complication in cancer patients. However, a subgroup of cancer patients presents with BM as the first symptom of metastatic cancer. Here we aimed to analyze the clinical course and prognostic factors of this particular BM patient population. Patients presenting with newly diagnosed BM without a history of metastatic cancer were identified from the Vienna Brain Metastasis Registry. Clinical characteristics and overall survival were retrieved by chart review. 459/2419 (19.0%) BM patients presented with BM as first symptom of advanced cancer. In 374/459 (81.5%) patients, an extracranial primary tumor, most commonly lung cancer, could be identified within 3 months after BM diagnosis. In 85/459 (18.5%) patients no extracranial primary tumor could be identified despite comprehensive diagnostic workup within the first 3 months after diagnosis of BM. Survival of patients with identified extracranial tumor differed only numerically from patients with cancer of unknown primary (CUP), however patients receiving targeted therapy after molecular workup showed significantly enhanced survival (20 months vs. 7 months; p = 0.003; log rank test). The GPA score showed a statistically significant association with median overall survival times in the CUP BM patients (class I: 46 months; class II: 7 months; class III: 4 months; class IV: 2 months; p < 0.001; log rank test). The GPA score has a strong prognostic value in patients with CUP BM and may be useful for patient stratification in the clinical setting. Comprehensive diagnostic workup including advanced imaging techniques and molecular tissue analyses appears to benefit patients by directing specific molecular targeted therapies.

Melanoma of unknown primary

Formally described in the 1960s, melanoma of unknown primary (MUP) is characterized by the finding of metastatic melanoma within the lymph nodes, subcutaneous tissues, and other distant sites without an evident primary lesion. The most likely hypothesis of its etiology is an immune-mediated regression of the primary after metastasis has occurred. In addition, patients with MUP appear to have equivalent or better outcomes compared with patients with known primaries of a similar stage.

Metastatic Melanoma of Uncertain Primary with 5-Year Durable Response after Conventional Therapy: A Case Report with Literature Review

A 51-year-old Thai woman presented with bilateral leg edema and painful left inguinal mass for 6 months. Physical examination revealed matted bilateral inguinal lymph nodes up to 9 cm in size. Otherwise, physical examinations including skin were unremarkable. The result of the lymph node incisional biopsy is consistent with that of metastatic melanoma. The extensive investigation demonstrated multiple intra-abdominal and inguinal lymph nodes without detectable primary tumor. Palliative radiation and conventional chemotherapy were prescribed. The CT scan between treatments showed that the response was stable disease, but the following CT scan demonstrated a gradual decrease in size from August 2012 to November 2017 including the lesions outside radiation fields. Moreover, she developed vitiligo during a follow-up visit. The previous data reported the median overall survival among the patients who were treated with conventional chemotherapy ranging from 9.1 to 9.3 months and whose 5-year survival was less than 10%. This case represented a metastatic melanoma of unknown primary who achieved a durable response by conventional treatment. The clinical features including nodal-only disease, vitiligo, and abscopal effect of radiation were considered to be the favorable factors.

Stage IV melanoma of unknown primary: A population-based study in the United States from 1973 to 2014

BACKGROUND

Melanoma of unknown primary (MUP) is incompletely described on a population level.

OBJECTIVE

We sought to characterize stage IV MUP in a population-based cancer registry.

METHODS

We developed a novel search algorithm to identify cases of stage IV MUP in the Surveillance, Epidemiology, and End Results 18 registries from 1973 to 2014. Cases of stage IV melanoma of known primary (MKP) served as a comparison group. Age-standardized incidence rates, demographic characteristics, adjusted disease-specific survival, and Cox proportional hazard models were calculated for MUP and MKP.

RESULTS

A total of 322 stage IV MUP cases and 12,796 stage IV MKP cases were identified in Surveillance, Epidemiology, and End Results 18 registries from 1973 to 2014. The incidence of stage IV MUP is increasing, particularly for patients younger than 30 years of age. In multivariate analyses, age older than 50 and a lack of surgical treatment were negative prognostic factors for stage IV MUP. Relative survival, but not 5-year adjusted disease-specific survival, was higher for stage IV MUP than for MKP.

LIMITATIONS

Limitations include the retrospective study design and possible misclassification of MUP.

CONCLUSIONS

The incidence of stage IV MUP is increasing, and stage IV MUP shares similar prognostic factors with stage IV MKP, including age and surgical treatment.

Melanoma Unknown Primary Brain Metastasis Treatment with ECHO-7 Oncolytic Virus Rigvir: A Case Report

Melanoma is considered an aggressive malignancy with a tendency of forming metastasis in the brain. Less than 10% of all melanoma cases present with unknown primary tumor location. This diagnose is yet to be fully understood, because there are only theoretical assumptions about the nature of the disease. Melanoma brain metastases have many severe side effects and, unfortunately, any disease related to the brain has limited therapeutic options due to the blood-brain barrier. The course of the disease after a treatment course is complicated to predict, and it is difficult to obtain long-lasting remission. In this report, we describe a female patient with unknown primary melanoma brain metastasis treated with the oncolytic ECHO-7 virus Rigvir^® after brain surgery. The patient has been stable, as monitored by magnetic resonance imaging, for more than 3.8 years with ongoing therapy. The median expected overall survival from the time of diagnosis is approximately 5 months. Additional positive effect could have been gained from use of the intranasal administration route, which is considered effective due to the direct anatomical connection between the nasal cavity and the central nervous system. However, further studies are required to fully understand this mode of drug administration.

Merkel Cell Carcinoma Patients Presenting Without a Primary Lesion Have Elevated Markers of Immunity, Higher Tumor Mutation Burden, and Improved Survival

Purpose: Patients presenting with nodal Merkel cell carcinoma without an identifiable (unknown) primary lesion (MCC-UP) are nearly twice as likely to survive compared with similarly staged patients with known primary lesions (MCC-KP). The basis of this previously reported finding is unclear.Experimental Design: Survival analyses and markers of immunity were evaluated in 123 patients with advanced MCC. Whole-exome sequence data were analyzed from 16 tumors.Results: As in prior studies, patients with nodal MCC-UP had strikingly improved MCC-specific survival as compared with MCC-KP patients (HR, 0.297; P < 0.001). Surprisingly, patients presenting with distant metastatic MCC-UP also had significantly improved survival (HR, 0.296; P = 0.038). None of the 72 patients with MCC-UP were immunosuppressed as compared to 12 of the 51 (24%) patients with MCC-KP (P < 0.001). Merkel polyomavirus oncoprotein antibody median titer was higher in MCC-UP patients (26,229) than MCC-KP patients (3,492; P < 0.001). In addition, the median number of nonsynonymous exome mutations in MCC-UP tumors (688 mutations) was markedly higher than MCC-KP tumors (10 mutations, P = 0.016).Conclusions: This is the first study to our knowledge to explore potential underlying immune-mediated mechanisms of MCC-UP presentation. In this cohort, MCC-UP patients were never immune suppressed, had higher oncoprotein antibody titers, and higher tumor mutational burdens. In addition, we show that nodal tumors identified in MCC-UP patients did indeed arise from primary skin lesions as they contained abundant UV-signature mutations. These findings suggest that stronger underlying immunity against MCC contributes to primary lesion elimination and improved survival. Clin Cancer Res; 24(4); 963-71. ©2017 AACR.

Metastatic melanoma of unknown primary in the temporalis muscle

Melanomas are aggressive cancers that present as cutaneous, mucosal and ocular lesions with the ability to metastasise widely. There are, however, occasions where lesions are found in distant sites such as lymph nodes, viscera and subcutaneous tissues without clinically apparent skin involvement. This is known as metastatic melanoma of unknown primary (MUP). Its presentation in skeletal muscle is rare, and the available literature is sparse. This article presents an 85-year-old woman with a MUP presenting in the right temporalis muscle, which was diagnosed with the aid of the ultrasound-guided core biopsy. The melanoma deposit was successfully excised, and no recurrence was identified. The patient is now under close follow-up.

Treatment Outcomes for Metastatic Melanoma of Unknown Primary in the New Era: A Single-Institution Study and Review of the Literature

BACKGROUND

Metastatic melanoma of unknown primary (MUP) is uncommon, biologically ill defined, and clinically understudied. MUP outcomes are seldom reported in clinical trials. In this study, we analyze responses of MUP patients treated with systemic therapy in an attempt to inform treatment guidelines for this unique population.

METHODS

New York University (NYU)'s prospective melanoma database was searched for MUP patients treated with systemic therapy. PubMed and Google Scholar were searched for MUP patients treated with immunotherapy or targeted therapy reported in the literature, and their response and survival data were compared to the MUP patient data from NYU. Both groups' response data were compared to those reported for melanoma of known primary (MKP).

RESULTS

The MUP patients treated at NYU had better outcomes on immunotherapy but worse on targeted therapy than the MUP patients in the literature. The NYU MUP patients and those in the literature had worse outcomes than the majority-MKP populations in 10 clinical trial reports.

CONCLUSIONS

Our study suggests that MUP patients might have poorer outcomes on systemic therapy as compared to MKP patients. Our cohort was small and limited data were available, highlighting the need for increased reporting of MUP outcomes and multi-institutional efforts to understand the mechanism behind the observed differences.

Metastatic Melanoma of a MetatarsalA Case Report

A 53-year-old woman presented with painful swelling of the right forefoot presenting clinically as a metatarsal stress fracture. Radiographs showed destructive changes, and diagnostic imaging revealed an aggressive neoplasm. The lesion was biopsied, and the pathologic diagnosis was metastatic melanoma. A thorough physical examination and advanced imaging did not reveal a primary tumor. Ray resection was performed with en bloc resection of the neoplasm. The patient continues to receive long-term immune stimulation chemotherapy 34 months after the ray resection.

Intramammary metastatic melanoma of unknown primary origin in a 58-year old patient: a case report

BACKGROUND

Malignant melanoma metastasis to the breast is a rare disease.

CASE PRESENTATION

We present the case of a 58-year-old postmenopausal Caucasian woman with metastatic malignant melanoma of unknown origin of the right breast. She presented with a palpable lump in the inferior quadrant of her right breast. The investigations concluded it was breast metastasis from a malignant melanoma of unknown origin. The treatment consisted of mastectomy and axillary lymph node dissection. Two lymph nodes were positive for tumor cells and one showed extracapsular extension. Our patient did not receive immediate adjuvant therapy. Six weeks after the surgery, our patient presented a relapse in the right axilla (a 6 × 4 cm mass) with positive internal mammary lymph nodes and a single brain metastasis. This relapse motivated an adjuvant treatment with partial regression of the disease. Currently, our patient presents multiple metastases with poor prognosis.

CONCLUSIONS

From this experience, we advocate an immediate aggressive handling of melanoma metastasis to the breast.

Prognosis of Mucosal, Uveal, Acral, Nonacral Cutaneous, and Unknown Primary Melanoma From the Time of First Metastasis

BACKGROUND

Subtypes of melanoma, such as mucosal, uveal, and acral, are believed to result in worse prognoses than nonacral cutaneous melanoma. After a diagnosis of distant metastatic disease, however, the overall survival of patients with mucosal, uveal, acral, nonacral cutaneous, and unknown primary melanoma has not been directly compared.

MATERIALS AND METHODS

We conducted a single-center, retrospective analysis of 3,454 patients with melanoma diagnosed with distant metastases from 2000 to 2013, identified from a prospectively maintained database. We examined melanoma subtype, date of diagnosis of distant metastases, age at diagnosis of metastasis, gender, and site of melanoma metastases.

RESULTS

Of the 3,454 patients (237 with mucosal, 286 with uveal, 2,292 with nonacral cutaneous, 105 with acral cutaneous, and 534 with unknown primary melanoma), 2,594 died. The median follow-up was 46.1 months. The median overall survival for those with mucosal, uveal, acral, nonacral cutaneous, and unknown primary melanoma was 9.1, 13.4, 11.4, 11.7, and 10.4 months, respectively. Patients with uveal melanoma, cutaneous melanoma (acral and nonacral), and unknown primary melanoma had similar survival, but patients with mucosal melanoma had worse survival. Patients diagnosed with metastatic melanoma in 2006-2010 and 2011-2013 had better overall survival than patients diagnosed in 2000-2005. In a multivariate model, patients with mucosal melanoma had inferior overall survival compared with patients with the other four subtypes.

CONCLUSION

Additional research and advocacy are needed for patients with mucosal melanoma because of their shorter overall survival in the metastatic setting. Despite distinct tumor biology, the survival was similar for those with metastatic uveal melanoma, acral, nonacral cutaneous, and unknown primary melanoma.

IMPLICATIONS FOR PRACTICE

Uveal, acral, and mucosal melanoma are assumed to result in a worse prognosis than nonacral cutaneous melanoma or unknown primary melanoma. No studies, however, have been conducted assessing the overall survival of patients with these melanoma subtypes starting at the time of distant metastatic disease. The present study found that patients with uveal, acral, nonacral cutaneous, and unknown primary melanoma have similar overall survival after distant metastases have been diagnosed. These findings provide information for oncologists to reconsider previously held assumptions and appropriately counsel patients. Patients with mucosal melanoma have worse overall survival and are thus a group in need of specific research and advocacy.

Plasma cells in primary melanoma. Prognostic significance and possible role of IgA

Melanoma is not only one of the most immunogenic cancers but also one of the most effective cancers at subverting host immunity. The role of T lymphocytes in tumor immunity has been extensively studied in melanoma, whereas less is known about the importance of B lymphocytes. The effects of plasma cells (PCs), in particular, are still obscure. The aim of this study was to characterize pathological features and clinical outcome of primary cutaneous melanomas associated with PCs. Moreover, we investigated the origins of the melanoma-associated PCs. Finally, we studied the outcome of patients with primary melanomas with PCs. We reviewed 710 melanomas to correlate the presence of PCs with histological prognostic markers. Immunohistochemistry for CD138 and heavy and light chains was performed in primary melanomas (PM) and in loco-regional lymph nodes (LN), both metastatic and not metastatic. In three PM and nine LN with frozen material, VDJ-rearrangement was analyzed by Gene Scan Analysis. Survival analysis was performed on a group of 85 primary melanomas >2 mm in thickness. Forty-one cases (3.7%) showed clusters/sheets of PCs. PC-rich melanomas occurred at an older age and were thicker, more often ulcerated and more mitotically active (P<0.05). PCs were polyclonal and often expressed IgA in addition to IgG. In LN, clusters/sheets of IgA+ PCs were found both in the sinuses and subcapsular areas. Analysis of VDJ-rearrangements showed the IgA to be oligoclonal. Melanomas with clusters/sheets of PCs had a significantly worse survival compared with melanomas without PCs while, interestingly, melanomas with sparse PCs were associated with a better clinical outcome (P=0.002). In conclusion, melanomas with sheets/clusters of PCs are associated with worse prognosis. IgG and IgA are the isotypes predominantly produced by these PCs. IgA oligoclonality suggests an antigen-driven response that facilitates melanoma progression by a hitherto unknown mechanism.