Primary sinonasal mucosal melanoma simulated as cystic lesions: a case report

Amelanotic Malignant Mucosal Melanoma of the Nasal Cavity: Case Report and Literature Review

Sinonasal malignant melanoma is a rare but aggressive tumor of the head and neck area. It has a poor prognosis. Common symptoms are nasal obstruction, epistaxis, or purulent rhinorrhea. Diagnosis relies on histopathology with immunohistochemistry (IHC) studies. Surgery is the essential treatment, most often supplemented by radiotherapy or immunotherapy. A 63-year-old female patient, with a history of right dacryocystorhinostomy and Parkinson's disease, consulted for symptoms of right nasal obstruction with increasing intensity accompanied by two episodes of mild unilateral epistaxis. Rigid optic examination showed a white-pinkish right obstructive supra-centimetric endonasal tumor. CT revealed an extensive tissue process of the right nasal cavity invading the maxillary sinus, the inferior and middle conchas. A biopsy of the lesion was conducted under local anesthesia. The immunohistochemical study has shown undifferentiated tumor with positive antibody anti PS100 and anti-melan A evoking malignant sinonasal melanoma. The patient underwent two surgeries for maxillectomies as she presented a first local recurrence. She was started on adjuvant radiotherapy. At one year of follow-up, she does not present any local or general signs of disease. Sinonasal melanoma is a particular entity of head and neck mucosal melanomas. The highest incidence is described to be in the seventh and eighth decades of life with no sex difference. IHC profiling of different melanoma subtypes showed the importance of alterations in the KIT gene, this genetic data may constitute a therapeutic target. After surgery, the important local recurrence rates and regional failure justify adjuvant radiotherapy also for resections in free margins. Most authors consider that prophylactic neck dissection is not necessary. Preoperative imaging features (CT scan) are characteristic and helpful for diagnosis. IHC is essential, has a high sensitivity for differentiating achromic melanomas from other neoplasms. Sinonasal achromic melanoma is a very uncommon tumor, invasive, and frequently associated with distant metastasis. Paraclinic examinations are essential for staging and guiding therapeutic management. Immunotherapy is a promising ground of research as it comes to metastatic and advanced disease.

Sinonasal melanoma: a systematic review of the prognostic factors

The objective was to evaluate the available published data on sinonasal melanoma and analyse its clinical features, treatment modalities, and prognostic factors. An electronic search was undertaken in March 2018 in multiple databases. Eligibility criteria included publications with sufficient clinical, histological, and immunohistochemical information to confirm the diagnosis. Seventy-three publications (439 cases) were included. The lesion was more prevalent in females than in males. There was a higher prevalence in the seventh and eighth decades of life. The lesions mainly presented as epistaxis and commonly involved the nasal cavity. Age (>67.6 years; P=0.0012), primary location (middle turbinate; P=0.0112), disease stage (advanced disease stage; P=0.0026), treatment (radiotherapy; P=0.0111), recurrence (recurrence presented; P=0.0137), and distant metastasis (distant metastasis presented; P=0.0011) were independently associated with a lower survival rate. Recurrence was significantly correlated with age (>67.6 years; P=0.0021), sex (males tended to present a higher recurrence rate than females; P=0.0051), disease stage (stages III and IV presented a higher recurrence rate than stages I and II; P=0.0331), and histological type (amelanotic lesions presented a higher index of recurrence than melanotic lesions; P=0.0095). In conclusion, sinonasal melanoma is a neoplasm with a poor prognosis, presenting a 30.69% possibility of survival after 5 years.