Positron Emission Tomography in Mucosal Melanomas of Head and Neck: Results from a South Asian Tertiary Cancer Care Center

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.

Diagnostic Performance of [18F]F-FDG Positron Emission Tomography (PET) in Non-Ophthalmic Malignant Melanoma: A Systematic Review and Meta-Analysis of More Than 10,000 Melanoma Patients

We described the diagnostic performance of [18F]F-FDG-PET in malignant melanoma by conducting a comprehensive systematic review and meta-analysis of the existing literature. The study was designed following PRISMA-DTA. Original articles with adequate crude data for meta-analytic calculations that evaluated [18F]F-FDG-PET and compared it with a valid reference standard were considered eligible. The pooled measurements were calculated based on the data level (patient/lesion-based). Regarding sub-groups, diagnostic performances were calculated for local, regional and distant involvement. The bivariate model was employed to calculate sensitivity and specificity. The initial search resulted in 6678 studies. Finally, 100 entered the meta-analysis, containing 82 patient-based (10,403 patients) and 32 lesion-based (6188 lesions) datasets. At patient level, overall, [18F]F-FDG-PET had pooled sensitivity and specificity of 81% (95%CI: 73-87%) and 92% (95%CI: 90-94%), respectively. To detect regional lymph node metastasis, the pooled sensitivity and specificity were 56% (95%CI: 40-72%) and 97% (95%CI: 94-99%), respectively. To detect distant metastasis, they were 88% (95%CI: 81-93%) and 94% (95%CI: 91-96%), respectively. At lesion level, [18F]F-FDG-PET had a pooled sensitivity and specificity of 70% (95%CI: 57-80%) and 94% (95%CI: 88-97%), respectively. Thus, [18F]F-FDG-PET is a valuable diagnostic modality for melanoma assessment. It was accurate in various clinical scenarios. However, despite its high specificity, it showed low sensitivity in detecting regional lymph node metastasis and could not replace lymph node biopsy.

A Systematic Review of Primary Temporal Bone Mucosal Melanoma

OBJECTIVE

Temporal bone mucosal melanomas (MMs) are rare, and patients may experience delays in diagnosis and treatment. Our objective was to better characterize the presentation, diagnosis, treatment modalities, and outcomes of this process.

DATA SOURCES

PubMed/Medline, CINAHL (EBSCOhost), and Web of Science databases were searched in all languages without restriction of publication dates.

STUDY SELECTION

Inclusion criteria included that the article was either a case report or a case series with individual case data. All non-English articles were excluded if the corresponding abstract lacked data on demographics, initial presentation, and clinical management.

DATA EXTRACTION

After full-text analysis, data pertaining to demographics, diagnosis, medical and surgical management modalities, and outcomes were extracted.

DATA SYNTHESIS

Data were qualitatively synthesized, and means and averages were obtained for all continuous variables. Overall survival was measured by the Kaplan-Meier method, and significance was measured through log-rank testing.

CONCLUSIONS

Clinicians should suspect temporal bone MM in the differential diagnosis of patients with bloody otorrhea in the context of a chronic serous otitis media or an associated cranial nerve palsy. If suspected, physicians should not delay the acquisition of a biopsy or imaging studies. Management is highly variable and must be decided on a case-by-case basis. Outcomes remain poor because of the high propensity for MM to metastasize.

Non-Cutaneous Melanoma, Findings and Prognostic Value of FDG PET/CT: A Case Series of 23 patients and review of the literature

Objectives

Non-cutaneous malignant melanomas (NCM) are rare malignancies. Due to their nonspecific symptoms, they present later in life. The value of FDG PET/CT in this group of patients is not clear. The aim of this study is to assess the role of FDG PET/CT in the management of NCM and its prognostic implication.

Methods

We retrospectively selected twenty-three patients with a diagnosis of NCM evaluated with FDG PET/CT in Shariati hospital between 2019 and 2021. The PET/CT data were reviewed and compared with available conventional imaging findings. Five patients died within five months. The surviving patients were followed within a time interval of 7 to 27.5 months after their PET/CT study, regarding their disease status.

Results

Among 23 patients (8 ocular, 5 sinonasal, 3 pharyngeal, 2 anorectal, 2 vulvovaginal, and 3 unknown primaries), PET/CT was able to detect residual primary disease, assess treatment response, and reveal or exclude metastases. Additional lesions compared to conventional imaging were found in five, while in one with brain metastases PET/CT was unable to detect lesions on MRI. Thirteen patients had negative PET/CT finding of which 11 (85%) did not have remarkable finding on follow-up. Metastatic disease was recognized in eight. Patients with extensive metastases on FDG PET/CT had a poorer outcome.

Conclusion

Similar to cutaneous melanoma, PET/CT is valuable in the management of NCM patients and is superior to conventional imaging modalities, with the exception of brain metastases. Patients with negative PET/CT findings have a better outcome as opposed to patients with significant positive PET/CT findings.

Primary Malignant Melanoma of the Oropharynx Presented on 18F-FDG PET/CT

ABSTRACT

Primary malignant melanoma in the oropharynx is extremely rare. A 49-year-old man presented with a 3-month history of progressive dysphagia. An outside CT scan of the head and neck showed a space-occupying lesion in the oropharynx. Staging with FDG PET/CT demonstrated a hypermetabolic mass in the right wall of the oropharynx. A biopsy revealed malignant melanoma. The patient underwent total resection of the tumor, with no recurrence after 6-month follow-up.

Practical Considerations When Interpreting FDG PET/CT Imaging for Staging and Treatment Response Assessment in Melanoma Patients

While FDG PET/CT bears a high sensitivity and specificity for the staging of stage III and IV melanoma as well as for the purpose of melanoma recurrence detection, overall results tend to vary from one part of the body to another as well as for melanoma from cutaneous or choroidal origin. In this paper, organ or site-related differences in sensitivity and specificity in melanoma patients, both from cutaneous and choroidal origin, as well as their impact on clinical decision making are discussed. Furthermore, with the advent of immunotherapy for the treatment of malignant melanoma, post-treatment related potential false positive findings have emerged, the knowledge of which is essential for accurate treatment response assessment. These post-treatment related potential false positive findings are summarized in this paper so as to help the nuclear medicine physician in avoiding erroneous interpretation of acquired FDG PET/CT images in melanoma patients receiving immuntherapy.

A Rare Case of Sinonasal Malignant Melanoma - Local, Regional, and Distant Spread Accurately Detected by 18F Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

Melanomas are usually cutaneous in origin but rarely can also arise from the mucosal linings in the body. Sinonasal melanomas arise from the mucosa of the nasal cavity and paranasal sinuses, which account for approximately 50% of mucosal melanomas in the body. 18F fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET/CT) has proven its role in malignant melanoma in staging especially in stage III and IV disease, restaging, assessing response to therapy and had affected in treatment change in significant number of cases. We present a case of sinonasal melanoma who underwent FDG PET/CT for staging and showed cervical lymph node and marrow metastases.

A 18FDG PET/CT-based volume parameter is a predictor of overall survival in patients with local advanced gastric cancer

Objective

The present study investigated the prognosis value of preoperative fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with local advanced gastric cancer (LAGC).

Methods

In total, 144 patients [median age 63 (range: 48−80) years old] with LAGC underwent¹⁸F-FDG PET/CT prior to any treatment. The maximum standardized uptake values (SUV_max), mean standardized uptake values (SUV_mean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion were measured on PET/CT and correlated with clinicopathological features and survival.

Results

Significant differences in SUV_mean, SUV_max, MTV and TLG were found according to Lauren’s classification, histologic grade and T category (P<0.05). During the 26.5-month follow-up, 51 (35.4%) patients died and 70 (48.6%) exhibited disease progression. The optimal thresholds of MTV and TLG were 15.1 cm³ and 47.3 cm³, respectively. The 3-year progression-free survival (PFS) and overall survival (OS) for patients with high TLG values were 30% and 38% compared to 38% and 47% for low TLG values, respectively (P<0.05). Univariate and multifactor analyses demonstrated that lymph node metastasis and T stage were independent prognostic factors for PFS; T stage, histologic grade and TLG were independent prognostic factors for OS (P<0.05). Molecular markers had no relationship with patient’s outcomes.

Conclusions

Metabolic activity of primary gastric tumors from ¹⁸F-FDG PET/CT is a prognostic factor in patients with LAGC.

The evaluation of malignant mucosal melanoma of nasal cavity with a rare occasion

Malignant mucosal melanoma is an uncommon disease with a low rate of survival. Malignancies of nasal mucosa which usually presents with nasal obstruction, epistaxis and back drip are difficult to treat and often have poor prognosis. The present case had presented to our clinic with classic symptoms and diagnostic findings of nasal polyposis. Consistently, the patient had previously been diagnosed with and treated for nasal polyposis in another ENT clinic. Physical examination, rhinoscopic examination, computed tomography (CT) scan of the head did not reveal any findings which might imply malignant formations. The operation had been planned for nasal polypectomy and taking deep biopsy specimens. The incised mass showed characteristic features of malignant tissues and the pathology report of the biopsy samples revealed that the specimen showed the histological signs of malignancy. Based on physical examination, CT findings and pathology reports the case was diagnosed as nasal mucosal melanoma. Following an oncosurgical operation, postoperative radio-therapy and chemotherapy were given to the patient and PET/CT examination of the patient did not indicate distant metastases.