Metastatic mucosal melanoma: imaging patterns of metastasis and recurrence

Primary non-cutaneous melanomas of the head and neck: Case series and review of the literature

Primary non-cutaneous melanoma is a rare type of melanoma that occurs mostly on mucosal surfaces. The head and neck region is the most common site for these melanomas. The following cases described herein include patients diagnosed with primary non-cutaneous melanomas. The locations included the parotid gland (one case), the submandibular gland (one case), and the nasal cavity and paranasal sinuses (three cases). Among these patients, one patient developed lymph node metastasis and one patient had distant metastasis. Treatment included endoscopic surgery (one case), endoscopic surgery with adjuvant radiotherapy (one case), open surgery (one case), and palliative chemotherapy (one case). One patient refused to receive treatment. After treatment, one patient had local recurrence. A local and distant recurrence was noted in one case. This report aims to describe clinical features, treatment options, and prognosis of primary non-cutaneous melanomas of the head and neck.

A Rare Case of Invasive Malignant Melanoma Metastasis in the Vulvar Mucosa 11 Years After Diagnosis and Treatment

Mucosal melanoma is rare and the occurrence of an invasive malignant melanoma metastasis 11 years post-initial diagnosis is equally uncommon. This is a case of a 66-year-old woman with a history of bilateral vulvar invasive melanoma, who presented with an enlarging inguinal mass with associated tenderness upon palpation. After a right inguinal excisional lymph node biopsy, the pathological findings determined the final diagnosis as metastatic melanoma. To the best of our knowledge, this is the first report of vulvar mucosal melanoma metastasis greater than 10 years after initial diagnosis and treatment in the English language. This case discusses how treatment options for metastatic mucosal melanoma pose a challenge in such cases where follow-up for medical care is lacking. It also highlights the need for further preventative techniques and research directed towards screening techniques, staging guidelines, and treatment options for mucosal melanoma.

In Vitro Effects of Photon Beam and Carbon Ion Radiotherapy on the Perineural Invasion of Two Cell Lines of Neurotropic Tumours

Primary mucosal melanoma (PMM) and pancreatic ductal adenocarcinoma (PDAC) are two aggressive malignancies, characterized by intrinsic radio-chemoresistance and neurotropism, a histological feature resulting in frequent perineural invasion (PNI), supported by neurotrophic factors secreted in the tumour microenvironment (TME), such as neurotrophin-3 (NT-3). Carbon-ion radiotherapy (CIRT) could represent an effective option in unresectable PMM and PDAC. Only a few data about the effects of CIRT on PNI in relation to NT-3 are available in the literature, despite the numerous pieces of evidence revealing the peculiar effects of this type of radiation on tumour cell migration. This in vitro study investigated for the first time the response of PMM and PDAC cells to NT-3 and evaluated the effects of conventional photon beam radiotherapy (XRT) and CIRT on cell viability, proliferation, and migration. Our results demonstrated the greater capacity of C-ions to generally decrease cell viability, proliferation, and migration, while the addition of NT-3 after both types of irradiation determined an increase in these features, maintaining a dose-dependent trend and acting more effectively as a chemoattractant than inductor in the case of migration.

Mucosal Melanomas of the Oral Cavity: A Tertiary Care Centre Experience of Surgically Treated Cases

Mucosal melanoma of oral cavity (MMO) is a relatively rare tumour comprising of 40% of all head and neck mucosal melanomas. This study assessed the treatment outcomes and factors affecting prognosis in oral cavity mucosal melanomas. The clinical case records of 25 cases of oral cavity mucosal melanomas treated in our institution during 2003-2013 were retrospectively reviewed. Various clinicopathological parameters were taken into consideration and statistical analysis done by Kaplan-Meier method and Cox's proportional hazards model. The most common sites of MMO were upper alveolus and hard palate (64%) followed by lower alveolus (28%). 57.1% mucosal melanomas of hard palate and upper alveolus had associated metastatic lymph nodes whereas all cases of MMO of lower alveolus had lymph node metastasis. Disease failure at distant sites was higher than that at primary site or lymph nodes. The most common site of distant metastases was brain. The 5-year OS for treated cases was 23.8% and among subsites, MMO of hard palate and upper alveolus had the highest survival. Metastasis to lymph nodes and bone infiltration by tumour significantly decreased the survival. Recurrence at primary site had the worst prognosis. MMO with lymph nodal involvement and bone erosion had poor prognosis. Due to high chances of lymph node metastases and disease recurrence in lymph nodes following treatment, it is essential to do an elective neck dissection for all cases of MMO. Disease failure at primary site was an independent predictor of outcome in MMO.

Anorectal and Genital Mucosal Melanoma: Diagnostic Challenges, Current Knowledge and Therapeutic Opportunities of Rare Melanomas

Mucosal melanomas (MM) are rare tumors, being less than 2% of all diagnosed melanomas, comprising a variegated group of malignancies arising from melanocytes in virtually all mucosal epithelia, even if more frequently found in oral and sino-nasal cavities, ano-rectum and female genitalia (vulva and vagina). To date, there is no consensus about the optimal management strategy of MM. Furthermore, the clinical rationale of molecular tumor characterization regarding BRAF, KIT or NRAS, as well as the therapeutic value of immunotherapy, chemotherapy and targeted therapy, has not yet been deeply explored and clearly established in MM. In this overview, focused on anorectal and genital MM as models of rare melanomas deserving of a multidisciplinary approach, we highlight the need of referring these patients to centers with experts in melanoma, anorectal and uro-genital cancers treatments. Taking into account the rarity, the poor outcomes and the lack of effective treatment options for MM, tailored research needs to be promptly promoted.

Diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in anorectal melanoma

To evaluate the diagnostic role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in initial staging and restaging of anorectal melanoma. This was a single-institution, retrospective observational study; patients for initial staging and with clinical or radiological suspicion of disease recurrence referred for PET/CT between January 2006 and December 2015 were included in the study. Diagnostic performance of PET/CT was evaluated for baseline staging and disease recurrence. A total of 61 patients who were referred for initial staging were included. PET/CT correctly detected primary lesion in 57 (93.44%) cases, regional nodes in 46 (75.4%) cases, nonregional nodes in 22 (36%) cases, and distant metastases in 25 (41%) cases. The sensitivity (SN); specificity (SP); positive predictive value (PPV); negative predictive value (NPV); and accuracy for primary lesion, regional nodes, nonregional nodes, and distant metastases were 96.6%, 100%, 100%, 50%, and 96.7%; 97.9%, 100%, 100%, 93.3%, and 98.4%; 100%, 100%, 100%, 100%, and 100%; and 100%, 100%, 100%, 100%, and 100%, respectively. A total of 24 patients were included for suspected recurrence/restaging. All the patients were treated previously by surgery, radiotherapy, or chemotherapy. PET/CT detected disease recurrence in 20 (83.3%) patients. Ten patients had recurrence at the primary site, 8 of whom also had distant metastases and 2 had only locoregional metastatic nodes. In the remaining 10 patients, there was no primary site recurrence; however, 2 patients had locoregional nodal and distant metastases and 8 patients had only distant metastases. PET/CT was false negative in 1 patient, which missed liver metastasis. SN, SP, PPV, and NPV of PET/CT was found to be 95%, 100%, 100%, and 75%, respectively, with accuracy of 96%. PET/CT demonstrates overall high diagnostic accuracy in the initial staging and detection of recurrent disease in cases of anorectal melanoma.

Multimodality Imaging and Genetics of Primary Mucosal Melanomas and Response to Treatment

Mucosal melanomas (MMs) are rare and aggressive tumors that arise from melanocytes in the mucosal tissues that line the respiratory, gastrointestinal, and urogenital tracts. Most MMs occur during the 6th and 7th decades of life. MMs may be asymptomatic but may also cause bleeding, pain, and itching, depending on the site of origin. Because of their asymptomatic or oligosymptomatic nature and the difficulty of visualizing them in some cases, they are often advanced tumors at patient presentation. MM staging varies depending on the site of the primary tumor. A simplified staging system allows classification of clinically localized disease as stage I, regional nodal involvement as stage II, and distant metastasis as stage III. MM differs genetically from its cutaneous counterparts. Common drivers in cutaneous melanoma such as B-raf proto-oncogene serine/threonine kinase (BRAF) have a lower mutation rate in MM, whereas mutations of other genes including the KIT proto-oncogene, receptor tyrosine kinase (KIT) and splicing factor 3b subunit 1 gene (SF3B1) are more common in MM. Complete resection is the best curative option. However, surgical intervention with wide local excision and negative margins may be difficult to attain because of the local anatomy and the extent of disease. In addition, despite aggressive surgical resection, most patients develop local recurrence and metastatic disease. Recent advances in the treatment of melanoma include immunotherapy and targeted therapy. Unfortunately, MMs have a relatively poor prognosis, with an overall 5-year survival rate of 25%. Online supplemental material is available for this article. ^©RSNA, 2021.

Immunotherapy combined with high- and low-dose radiation to all sites leads to complete clearance of disease in a patient with metastatic vaginal melanoma

A 73-year-old woman with metastatic vaginal mucosal melanoma that had progressed on ipilimumab and nivolumab experienced clinical and radiographic complete response to dual checkpoint inhibitor immunotherapy given in combination with high-dose plus low-dose radiation. General characteristics and treatment options in this disease are highlighted.

Magnetic resonance features of sinonasal melanotic mucosal melanoma

A 67-year-old man presented to ear, nose and throat department complaining of nasal congestion and recurrent epistaxis for 5 months. Nasal endoscopy revealed a pigmented polyp obstructing the right nasal cavity. MRI with contrast agent showed a right nasal cavity polypoid mass with hyper signal intensity (SI) both in non-enhanced T1-w and diffusion imaging, marked hypo SI in T2-w sequences and avidly contrast enhancement characterised by rapid wash-in without significant wash-out on dynamic perfusion imaging. Histological specimen showed epithelioid and spindle cells with focal intense pigmentations and immunohistochemical features compatible with primary melanotic sinonasal mucosal melanoma (SNM). As melanotic SNM shows MRI pathognomonic high non-enhanced T1-w SI, this case underlines the crucial role of MRI not only in assessing the local tumour extension/recurrence but also in increasing the diagnostic confidence of detecting melanotic SNM. Thus, MRI should be always performed in case of clinical-endoscopic suspicion of SNM.

PET/MRI vs PET/CT in Head and Neck Imaging: When, Why, and How?

The increasing availability of hybrid PET/MRI systems has led to a breadth of new publications and opportunities for use of PET/MRI. While PET/CT has been a valuable tool for oncologic staging, including head and neck malignancy, there are several theoretical and practical advantages a PET/MRI system would have over PET/CT in head and neck imaging. This review article discusses the established role of PET/CT, early evidence for the role of PET/MRI, and protocol considerations for both PET/CT and PET/MRI as they apply to head and neck imaging.

Nodal and distant metastases in sinonasal mucosal melanoma: A population-based analysis

OBJECTIVES/HYPOTHESIS

Sinonasal mucosal melanoma (SNMM) is a rare malignant neoplasm. No study to date has analyzed the impact that nodal metastases and distant metastases at diagnosis have on overall survival (OS) and disease-specific survival (DSS).

STUDY DESIGN

Retrospective database review.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for cases of SNMM. Descriptive statistics were used analyze patient demographic and clinicopathologic variables. The Kaplan-Meier model was used to analyze survival, and the Cox proportional hazards model was used for multivariate analysis.

RESULTS

Three hundred twenty-eight cases of SNMM were identified. The most frequent sinonasal anatomic location was the nasal cavity in 279 (73.0%) patients, followed by the maxillary sinus in 60 (15.7%) patients. Regional nodal metastases at diagnosis occurred in 33 (8.6%) patients, whereas distant metastases at diagnosis occurred in 41 (10.7%) patients. Five-year OS was 22.7%, and 5-year DSS was 26.8%. The presence of positive nodes at diagnosis (OS P < .0001, DSS P < .0001), distant metastases at diagnosis (OS P = .0442, DSS P = .0442), primary tumor site (OS P < .0001, DSS P < .0001), and increasing age (OS P = .0012, DSS P = .0016) were found to be significant as negative predictors of OS and DSS.

CONCLUSIONS

SNMM is a rare pathologic entity with a poor prognosis. The presence of nodal and distant metastases at diagnosis are negative prognostic factors in OS and DSS. These factors can be used in the development of new models of risk stratification and to inform treatment strategies and surveillance patterns.

LEVEL OF EVIDENCE

NA Laryngoscope, 130:622-627, 2020.

Pigmented Conjunctival Lesions as Presenting Signs of Vaginal Melanoma

A 43-year-old woman was referred to an oculoplastic surgeon for the evaluation of 2 small pigmented lesions in the tarsal conjunctiva. She underwent a biopsy of the lesions, both of which were found to be consistent with metastatic melanoma. Follow-up with the patient revealed that she had been hospitalized for balance issues and headaches. An MRI of her brain revealed a hemorrhagic mass and several smaller foci suspicious for metastatic lesions. A thorough workup included an evaluation for bloody vaginal discharge. Biopsy of a pigmented portion of the vaginal mucosa lesion revealed BRAF-positive melanoma. This was determined to be the primary site of her malignant metastatic melanoma, which caused her death within 6 months of presentation.

SSeCKS/AKAP12 scaffolding functions suppress B16F10-induced peritoneal metastasis by attenuating CXCL9/10 secretion by resident fibroblasts

SSeCKS/Gravin/AKAP12 (SSeCKS) is a kinase scaffolding protein known to suppress metastasis by attenuating tumor-intrinsic PKC- and Src-mediated signaling pathways [1]. In addition to downregulation in metastatic cells, in silico analyses identified SSeCKS downregulation in prostate or breast cancer-derived stroma, suggesting a microenvironmental cell role in controlling malignancy. Although orthotopic B16F10 and SM1WT1[Braf^V600E] mouse melanoma tumors grew similarly in syngeneic WT or SSeCKS-null (KO) mice, KO hosts exhibited 5- to 10-fold higher levels of peritoneal metastasis, and this enhancement could be adoptively transferred by pre-injecting naïve WT mice with peritoneal fluid (PF), but not non-adherent peritoneal cells (PC), from naïve KO mice. B16F10 and SM1WT1 cells showed increased chemotaxis to KO-PF compared to WT-PF, corresponding to increased PF levels of multiple inflammatory mediators, including the Cxcr3 ligands, Cxcl9 and 10. Cxcr3 knockdown abrogated enhanced chemotaxis to KO-PF and peritoneal metastasis in KO hosts. Conditioned media from KO peritoneal membrane fibroblasts (PMF), but not from KO-PC, induced increased B16F10 chemotaxis over controls, which could be blocked with Cxcl10 neutralizing antibody. KO-PMF exhibited increased levels of the senescence markers, SA-β-galactosidase, p21^waf1 and p16^ink4a, and enhanced Cxcl10 secretion induced by inflammatory mediators, lipopolysaccharide, TNFα, IFNα and IFNγ. SSeCKS scaffolding-site mutants and small molecule kinase inhibitors were used to show that the loss of SSeCKS-regulated PKC, PKA and PI3K/Akt pathways are responsible for the enhanced Cxcl10 secretion. These data mark the first description of a role for stromal SSeCKS/AKAP12 in suppressing metastasis, specifically by attenuating signaling pathways that promote secretion of tumor chemoattractants in the peritoneum.

Anorectal malignant melanoma: curative abdominoperineal resection: patient selection with 18F-FDG-PET/CT

Background

Anorectal malignant melanomas (ARMM) are rare tumors, characterized by an early lymphatic spread and distant metastasis, resulting in an extremely poor overall survival. The objective of this study was to determine the pattern of regional lymph node metastasis (LNM) by computed tomography (CT) and 18F-FDG-PET/CT in patients undergoing abdominoperineal resection (APR) and its impact on oncologic outcome.

Methods

A retrospective analysis of six consecutive patients who underwent APR due to primary ARMM was performed. Patients were staged by CT and PET/CT.

Results

Four out of six patients had preoperative LNM involvement (two patients inguinal and perirectal, one iliacal, one perirectal), with two of them presenting with distant metastases additionally. Inguinal/iliacal LNM in two patients as well as liver metastasis in one patient was seen in PET/CT and missed by CT. The three patients with initial inguinal/iliacal LNM died during the observation period (overall survival: 10 (6–18) months). The three patients without inguinal/iliacal LNM involvement are currently alive, one patient showing a slowly progressive disease since 5 years, and two patients are tumor-free since 8.5 and 1.5 years (the patients had initial perirectal LNM).

Conclusions

In ARMM, PET/CT is superior to CT in detection of LNM and distant metastasis. APR is possibly a curative approach if the PET/CT shows exclusively perirectal LNM despite locally advanced tumor growth.

Management of sinonasal mucosal melanomas and comparison of classification staging systems

OBJECTIVE

The aim of this study was to describe treatment results in patients with sinonasal mucosal melanomas (SMMs) and to compare three different classification staging systems.

MATERIALS AND METHODS

From 1988 to 2013, we performed a retrospective study of 20 patients with primary sinonasal melanomas. The median age at diagnosis was 71 years. There were 10 males and 10 females.

RESULTS

Nine SMMs (45%) were originated in the ethmoidal sinus complex, four (20%) in the inferior turbinate, three (15%) in the nasal septum, two (10%) in the maxillary sinus, and two (10%) in the nasal vestibule. Local recurrence was diagnosed in eight patients (40%), and six out of 20 patients (30%) developed distant metastasis during the course of their disease. The adjusted survival rates at three and five years were 47% and 34%, respectively. The adjusted three-year survival rate according to the sinonasal staging system 7th edition for SMM (TNM-SMM) was 60% in T3 stage, 50% in T4a stage, and 34% in T4b stage (p = 0.05). According to Thompson's staging system, survival was 33% for group one, 58% for group two, and 0% for group three (p = 0.006). With the sinonasal staging system 7th edition for carcinoma (TNM-CAR) survival was 33% in T1, 100% in T2 and T3, 0% in T4a, and 34% in T4b (p = 0.006).

CONCLUSIONS

Our experience confirms the distribution of patients according to survival rates was better with the TNM-SMM than with Thompson's or the TNM-CAR systems.

Extracutaneous melanomas: a primer for the radiologist

Objective

The purpose of this article is to provide a comprehensive review of the imaging features of extracutaneous melanomas.

Conclusion

Extracutaneous melanomas are clinically and biologically distinct from their more common cutaneous counterpart with higher frequency of metastatic disease and poorer overall prognosis. Complete surgical excision is the treatment of choice whenever possible; systemic therapy in the form of conventional chemotherapeutic agents as well as novel targeted agents is used for advanced/ metastatic disease. Multiple imaging modalities including US, CT, MRI and FDG-PET/CT play important roles in the evaluation of the primary tumour, assessment of metastatic disease and monitoring response to treatment. Radiologists should be aware of the typical imaging manifestations of extracutaneous melanoma, the distinct patterns of metastatic involvement as well as treatment response and toxicities associated with newer molecular targeted and immunotherapies to optimally contribute to patient management.

Teaching points

• Mucosal melanoma is clinically and biologically distinct from cutaneous melanoma.

• Mucosal melanoma has a higher rate of metastatic disease than the cutaneous subtype.

• Imaging is helpful in assessment of disease and response to treatment.