Malignant melanoma of the sinonasal cavity: explanation of magnetic resonance signal intensities with histopathologic characteristics

Head and neck mucosal melanoma: radiological considerations and UK imaging guidelines

PURPOSE

Awareness of head and neck mucosal melanoma (HNMM) is important, as incorrect work-up can impact on the investigation and management of this rare and aggressive cancer. Following on from the 2020 HNMM UK guidelines, we set out the imaging recommendations and their rationale. To illustrate the key imaging characteristics, we also include a case series from our centre.

METHODS

All HNMM cases managed at our institution from January 2016 to January 2021 were identified, and the available imaging for each patient was reviewed. For each patient, the age, gender and location of primary tumour was recorded together with key staging and diagnostic imaging parameters.

RESULTS

A total of 14 patients were identified. The median age was 65 years with a female to male ratio of 1.33:1. Primary tumours were sinonasal in location in 93% of cases, with 7% of patients having metastatic neck nodes at presentation and 21% of cases having distant metastatic disease at presentation.

CONCLUSION

This data set is in general concordance with other published series regarding the sinonasal origin of the vast majority of HNMM tumours along with the proportion of patients with metastatic neck nodes and distant metastases at presentation. We recommend dual-modality imaging with computed tomography (CT) and magnetic resonance imaging (MRI) of primary tumours whenever possible. In the systematic staging of HNMM, positron emission tomography (PET)-CT should be strongly considered, together with MRI of the brain. Pre-biopsy imaging of HNMM tumours is advisable whenever possible.

Definitive treatment for head and neck mucosal melanoma

Head and neck mucosal melanoma is a rare clinical subtype of melanoma or head and neck cancer. Mucosal melanoma is aetiologically and molecularly distinct from cutaneous melanoma. The therapeutic efficacy of immune checkpoint inhibitors for head and neck mucosal melanoma remains unclear. Surgery is considered as the mainstay of treatment for locally advanced head and neck mucosal melanoma, and adjuvant radiotherapy has a role in local disease control. New treatment modalities, such as targeted therapy and immunotherapy, have changed the treatment of cutaneous melanoma. However, patients with mucosal melanoma have been excluded from most Phase III clinical trials. Due to its rarity, outcome data for locally advanced head and neck mucosal melanoma are scarce and are mainly based on retrospective studies with limited case numbers. The objective of this review was to provide an update and overview of clinical trials, prospective observational studies and retrospective studies and discuss future directions for multimodal treatment of locally advanced head and neck mucosal melanoma.

Quantitative analysis of a posterior fossa teratomas with unusual CT and MR Characteristics--illustrative case

BACKGROUND

Intracranial teratomas or other cystic lesions with atypical imaging manifestations can still be frequently seen clinically. The specific reasons for unusual imaging manifestations need to be further explored.

OBSERVATIONS

A case of adult teratoma in the posterior fossa with unusual imaging manifestations was reported. The chemical composition of its cystic fluid was quantitatively detected, and in vitro imaging simulation experiments were performed on some fluid substances with similar cystic fluid properties to explore the reasons for special imaging manifestations. The content of inorganic substances and protein in the cystic fluid were both low, with no melanin detected. In vitro experiments revealed that MR T1 signals could increase with protein content rising and changes in MR T2 signals presented no obvious correlation with it. CT values increased gradually with protein concentration rising. The substances with similar viscosity had similar CT values, whereas substance viscosity showed no significant correlation with changes in MR signals.

CONCLUSION

The abnormality of imaging manifestations cannot be confirmed as the result of "high protein content", nor can it be simply attributed to bleeding. Further research is required for the impact of the combination of paramagnetic particles and biofluid on imaging.

Differentiating sinonasal malignant melanoma from squamous cell carcinoma using DWI combined with conventional MRI

PURPOSE

This study aimed to investigate the feasibility of diffusion-weighted imaging (DWI) in combination with conventional MRI features to differentiate sinonasal malignant melanoma (SNMM) from sinonasal squamous cell carcinoma (SNSCC).

METHODS

A total of 37 patients with SNMM and 44 patients with SNSCC were retrospectively reviewed. Conventional MRI features and apparent diffusion coefficients (ADCs) were evaluated independently by two experienced head and neck radiologists. ADCs were obtained from two different regions of interest (ROIs) including maximum slice (MS) and small solid sample (SSS). Multivariate logistic regression analysis was performed to identify significant MR imaging features in discriminating between SNMM and SNSCC. Receiver operating characteristic (ROC) curves were used to assess the diagnostic performance.

RESULTS

SNMMs were more frequently located in the nasal cavity, with well-defined border, T1 Septate Pattern (T1-SP) and heterogeneous T1 hyperintensity, whereas SNSCCs were more frequently located in the paranasal sinus, with homogenous T1 isointensity, ill-defined border, reticular or linear T2 hyperintensity, and pterygopalatine fossa or orbital involvement (all p < 0.05). The mean ADCs of SNMM (MS ADC, 0.85 × 10^-3mm²/s; SSS ADC, 0.69 × 10^-3mm²/s) were significantly lower than those of SNSCC (MS ADC, 1.05 × 10^-3mm²/s; SSS ADC, 0.82 × 10^-3mm²/s) (p < 0.05). With a combination of location, T1 signal intensity, reticular or linear T2 hyperintensity, and a cut-off MS ADC of 0.87 × 10^-3mm²/s, the sensitivity, specificity, and AUC were 97.3%, 68.2%, and 0.89, respectively.

CONCLUSION

DWI combined with conventional MRI can effectively improve the diagnostic performance in differentiating SNMM from SNSCC.

Preoperative Misdiagnosis of Malignant Mucosal Melanoma of the Nasal Septum by MRI

Malignant sinonasal mucosal melanoma is a rare and aggressive neoplasm. As it shows nonspecific clinical symptoms, magnetic resonance imaging (MRI) is the most effective diagnostic tool. Before a mass is histopathologically confirmed, MRI is regarded as the optimal differential diagnostic procedure, especially in patients who present with a unilateral sinonasal cavity mass. However, we recently treated a patient who showed atypical MRI findings, resulting in a preoperative misdiagnosis of a vascular tumor. By pathologic examination, the patient was confirmed to have a malignant mucosal melanoma that originated from the nasal septum. This case demonstrates that unilateral nasal cavity masses that present with nonspecific symptoms, such as epistaxis, should be evaluated for possible malignant neoplasms, even if the mass has benign-looking characteristics in preoperative endoscopic findings and MRI images.

An Unusual Polypoid Septal Mucosal Melanoma: Overview and Diagnostic Pitfalls

Sinonasal mucosa is an area of high melanocyte density compared to other mucosa-lined sites. Sinonasal mucosal melanomas (SNMM) most commonly arise from the nasal cavity and the paranasal sinuses. Due to their obscure anatomic location and lack of early symptomatology, SNMM are often diagnosed in an advanced stage. The majority of patients who present with symptoms complain of unilateral nasal dysfunction, such as obstruction and epistaxis.

We hereby report a case of an 86-year-old female, who presented with a three-year history of progressive right-sided nasal obstruction and recurrent epistaxis. Posterior rhinoscopy and endoscopy revealed a polypoid, fleshy lesion whose coloration varied from mildly pigmented to amelanotic. Inverted sinonasal papilloma was included in the differential diagnosis due to MRI findings. Post-resection histopathology indicated a mucosal melanoma. Typically, amelanotic lesions are rare, more difficult to diagnose and associated with worse prognosis due to both their aggressiveness and delayed diagnosis.

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.

Primary Mucosal Melanoma Presenting with a Unilateral Nasal Obstruction of the Left Inferior Turbinate

We report the case of a primitive nasal melanoma in an 82-year-old patient, showing how this rare malignancy, with non-specific signs and symptoms, can represent a challenging diagnosis for the physician. A 82-year-old Caucasian patient presented for unilateral nasal obstruction and occasional epistaxis. Computerized tomography (CT) and magnetic resonance imaging (MRI) of the facial massif revealed turbinate hypertrophy and a polypoid phlogistic tissue isointense in T1 with an intermediate signal in T2 and Short-TI Inversion Recovery (STIR)-T2, occupying the middle meatus and the anterior upper and lower left meatus with partial obliteration of the ostium and the infundibulum of the maxillary sinus. The Positron emission tomography (PET) exam was negative for metastases. Conservatory surgery in the left anterior video rhinoscopy was performed, allowing a radical 4-cm tumor excision. Histology reported epithelioid cell melanoma, PanK−, CD45−, and PanMelanoma+. Adjuvant radiotherapy was suggested, even considering a complete resection as the result of surgery. No local or systemic relapse was noticed at the 2-month follow-up visit. Although mucosal melanoma is a rare and aggressive malignancy characterized by a poor prognosis, early diagnosis allows a more conservative approach, with little surgical difficulty and no aesthetic effect. Our case raises awareness of the importance of early intervention even in those cases where the clinic symptoms and diagnostic images show uncertain severity.

Mucosal Melanoma of the Hard Palate: Surgical Treatment and Reconstruction

Mucosal melanomas of the head and neck region are uncommon pathologies that can affect the oral cavity, and are characterized by a high rate of mortality. Considering the lack of knowledge regarding risk and prognostic factors, current best clinical practice is represented by a large surgical excision with disease-free margins, eventually associated with a reconstructive flap. Indeed, given the frequent necessity of postoperative radiotherapy and fast healing process, a reconstruction of the surgical gap is advisable. Even if several flaps have been most commonly used, the submental island flap represents a valid alternative thanks to local advantages and similar oncologic outcomes compared to free flaps.

Mucosal Melanoma Originating From the Eustachian Tube

A 77-year-old man was referred with a 4-month history of hearing impairment and ear fullness of the left ear. Otoscopic examination revealed an effusion in the left middle ear, and nasal endoscopic examination revealed a dark polypoid lesion at the opening of the left Eustachian tube. In addition to the lesion of the Eustachian tube, a dark mucosal lesion was seen at the posterior choana and the posterior end of the nasal septum. Endoscopic biopsy was done and pathologic result was consistent with malignant melanoma. Wide surgical excision with postoperative radiotherapy was performed; multiple metastases were detected 4 months after the treatment. Mucosal melanoma originating from nasopharynx was extremely rare, but careful examination of nasopharyngeal area should be considered when the patient presents with unilateral middle ear effusion, especially in older age.

Melanoma of the Sinonasal Tract: Value of a Septate Pattern on Precontrast T1-Weighted MR Imaging

BACKGROUND AND PURPOSE

Various tumors of the sinonasal tract can exhibit high signal intensity on T1WI. The purpose of this study was to determine the value of a septate pattern on precontrast T1WI for diagnosing sinonasal melanoma.

MATERIALS AND METHODS

Retrospectively, 3 observers independently reviewed MR images of 31 histologically proved sinonasal melanomas with special attention to the presence or absence of a septate pattern on precontrast T1WI, defined as alternating hyperintense and hypointense striations on precontrast T1WI. For comparison, we evaluated the prevalence of a septate pattern on precontrast T1WI in 106 nonmelanomatous sinonasal malignant tumors with 16 different histologic types. We also tried to identify the histopathologic features responsible for the septate pattern on precontrast T1WI.

RESULTS

Twenty-seven (87.1%) of 31 sinonasal melanomas showed hyperintense foci on T1WI, among which a septate pattern on precontrast T1WI was seen in 23 (74.2%), while 22 (20.8%) of 106 nonmelanomatous malignant tumors demonstrated hyperintense foci on T1WI, among which only 3 (2.8%) showed a septate pattern on precontrast T1WI. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of a septate pattern on precontrast T1WI for the diagnosis of sinonasal melanoma were 74%, 97%, 88%, 93%, and 92%, respectively. Although limited due to the retrospective nature, 4 of 23 histologically reviewed sinonasal melanomas revealed an uneven distribution of melanin with alternating melanin and fibrous bands within the tumors.

CONCLUSIONS

A septate pattern on precontrast T1WI might be an adjunctive imaging finding for the diagnosis of sinonasal melanoma. This might be attributed histologically to an uneven distribution of melanin and hemorrhage within the tumors.

Clinical and Imaging Features of Noncutaneous Melanoma

OBJECTIVE

The purpose of this article is to summarize the epidemiologic characteristics, clinical aspects, and radiologic appearance of as well as the management considerations and differential diagnoses for noncutaneous primary melanomas occurring at specific anatomic sites. Primary ocular, sinonasal, meningeal, biliary, adrenal, alimentary tract, and genitourinary melanomas are highlighted.

CONCLUSION

Noncutaneous primary melanomas are a complex group of malignancies with biologic findings that are unique when compared with findings for cutaneous melanomas. Each noncutaneous primary melanoma has its own specific diagnostic and management challenges, depending on the anatomic location where they arise.

Sinonasal malignant melanoma with diffuse carcinomatosis: initial PET/CT staging and follow-up CT/MR imaging

Mucosal malignant melanoma of the head and neck is a rare but aggressive type of melanoma with poor clinical prognosis and outcome. Its nonspecific symptomatology frequently leads to its delayed diagnosis until advanced stages of the disease. The author presents a case of primary sinonasal amelanotic melanoma with preoperative F-18 FDG PET/CT showing diffuse bone metastasis only two months after the onset of epistaxis and nasal congestion, and subsequent postsurgical CT/MR showing diffuse soft tissue tumor dissemination and malignant pleural effusion.

Magnetic resonance imaging (MRI) appearances of primary amelanotic malign melanoma in the nasal cavity: a rare case

Malign melanoma of the nasal cavity that arises at such an unusual location is an exceptional case only occasionally mentioned in the literature. An amelanotic form, which is an uncommon type for this malignancy, also has an unusual radiological appearence from the classic melanotic form. We report here the magnetic resonance imaging (MRI) findings of a 46-year-old man who had a nasal cavity mass diagnosed as an amelanotic malign melanoma and discuss the importance of differential diagnosis with such an unusual radiological manifestation in this location.

Mucosal melanoma of the nasal cavity and paranasal sinuses

Mucosal melanoma of the nasal cavity and paranasal sinuses is a rare disease, but its incidence appears to be increasing. The mean age at diagnosis is between 65 and 70 years. Unilateral nasal obstruction and epistaxis are the most common presenting complaints. Melanoma arises in the septum or lateral wall of the nasal cavity in the great majority of cases. The histological diagnosis is based on specific immunohistochemical labelling and is usually established at an advanced stage of disease: stage T3 or T4 tumours according to the 7th edition of the American Joint Committee on Cancer (AJCC) classification of tumours. First-line treatment consists of surgery. The place of intranasal endoscopic surgery remains controversial due to the difficulty of controlling surgical margins and should be reserved for experienced teams. Adjuvant radiotherapy is usually performed due to its efficacy on local and regional disease control. Five-year overall survival of mucosal melanoma of the nasal cavity and paranasal sinuses in the most recent series does not exceed 40%. Local recurrence is observed in about 50% of cases and metastatic disease is common. The quality of initial tumour resection with negative surgical margins is the most important prognostic factor for tumours confined to the nasal cavity. Hopes for improvement of survival are based on early diagnosis, progress in radiotherapy techniques and cell and gene therapy that are currently under evaluation.

Immunoglobulin G4-related sclerosing disease mimicking invasive tumor in the nasal cavity and paranasal sinuses

IgG4RSD affecting the nasal cavity and paranasal sinuses is extremely rare. A 71-year-old man presented with an invasive mass in the nasal cavity and paranasal sinuses that was confirmed by immunostaining to be IgG4RSD. The occurrence of this disease in the nasal cavity and paranasal sinuses can resemble a malignant tumor on diagnostic imaging.

Outcome of sinonasal melanoma: clinical experience and review of the literature

BACKGROUND

Primary sinonasal malignant melanoma (SNMM) is a rare clinical entity. There is neither a classification nor a staging system nor an evidence-based treatment concept established. Our objective was to find potential risk factors predicting the outcome.

METHODS

Twenty-five patients with histologically confirmed SNMM were consecutively included and retrospectively analyzed. Staging methods were nasal endoscopy, CT, MRI, and positron emission tomography (PET) scan. Patients were selected for a curative or palliative concept. All patients had postoperative follow-up with control-MRI at 3 and 6 months. Restaging was performed when local recurrence occurred.

RESULTS

Nineteen patients underwent primary surgery with curative intention; in 16 cases with tumor free margins. Thirteen patients (68%) had transnasal endoscopic surgery, 4 lateral rhinotomy, and 2 transfacial approach with orbital exenteration. Six patients (32%) had palliative therapy and 7 patients (37%) had adjuvant radiotherapy. Despite radical operations, 6 patients (37%) showed local recurrence and 8 patients (50%) developed distant metastasis. In 2 patients with incomplete surgery, regional metastasis was noted. The median disease-free interval was 18 months, and the median overall survival rate was 23 months.

CONCLUSION

SNMMs of the ethmoid and maxillary sinuses have a worse prognosis than other localizations in the nasal cavity; infiltration into the skull base, orbit, or facial soft tissue correlates with a very poor outcome corresponding to the palliative situations. Furthermore, local recurrence insinuates aggressive disease with short survival rate. A main difference from its cutaneous counterpart seems to be a primary tendency to hematogenic spread. Further research is needed to confirm these findings.

MR imaging features of primary mucosal melanoma of the eustachian tube: report of 2 cases

We observed 2 cases of malignant melanoma arising from the eustachian tube with MR imaging. In this region, we explored further characteristics of primary mucosal melanoma. We discuss the value of using MR imaging to diagnose and treat patients with melanoma in the eustachian tube. In addition, we introduce the key points to differentiate melanoma from some common diseases in the region.

[Sinonasal mucosal malignant melanoma]

INTRODUCTION

Mucosal melanomas are rare tumors, and primary sinonasal malignant melanomas uncommon tumors that are frequently misclassified. Differential diagnosis should rule out other sinonasal malignancies, including carcinoma, lymphoma, sarcoma, and olfactory neuroblastoma.

CASE

We report two new cases of sinonasal melanoma. One involved a 68-year-old man being followed for chronic sinusitis, despite antibiotics; he presented a tumor of the right nasal cavity. The second case was that of a 77-year-old woman, referred for painful gingival swelling shown to involve osteolytic growth in the left maxillary sinus. In both cases, pathologic examination of the biopsy samples concluded that these were sinonasal malignant melanomas.

DISCUSSION

Histologically, the diagnosis is very difficult because of the polymorphic features of this tumor, and immunohistochemical studies are very important. The relative inaccessibility of the mucosa to self-examination often delays diagnosis and leads to late detection and poor prognosis.

Role of MR and CT in the paranasal sinuses

This article discusses the benefits and drawbacks of MR imaging and computed tomography as they relate to sinus disease.

Sinonasal tract and nasopharyngeal melanomas: a clinicopathologic study of 115 cases with a proposed staging system

Primary sinonasal tract mucosal malignant melanomas are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. A total of 115 cases of sinonasal tract mucosal malignant melanoma included 59 females and 56 males, 13-93 years of age (mean 64.3 years). Patients presented most frequently with epistaxis (n = 52), mass (n = 42), and/or nasal obstruction (n = 34) present for a mean of 8.2 months. The majority of tumors involved the nasal cavity (n = 34), septum alone, or a combination of the nasal cavity and sinuses (n = 39) with a mean size of 2.4 cm. Histologically, the tumors were composed of a variety of cell types (epithelioid, spindled, undifferentiated), frequently arranged in a peritheliomatous distribution (n = 39). Immunohistochemical studies confirmed the diagnosis of sinonasal tract mucosal malignant melanomas with positive reactions for S-100 protein, tyrosinase, HMB-45, melan A, and microphthalmia transcription factor. Sinonasal tract mucosal malignant melanomas need to be considered in the differential diagnosis of most sinonasal malignancies, particularly carcinoma, lymphoma, sarcoma, and olfactory neuroblastoma. Surgery accompanied by radiation and/or chemotherapy was generally used. The majority of patients developed a recurrence (n = 79), with 75 patients dying with disseminated disease (mean 2.3 years), whereas 40 patients are either alive or had died of unrelated causes (mean 13.9 years). A TNM-type classification separated by anatomic site of involvement and metastatic disease is proposed to predict biologic behavior.