Primary sinonasal malignant melanoma with systemic metastasis in a non-gray horse

A 27-y-old Anglo-Arabian gelding with bay coat color was presented with a swelling of the left maxillary region. Fenestration on the left maxilla revealed that the left maxillary sinus was filled with black-red tissue. A portion of the tissue was excised and diagnosed histologically as malignant melanoma. Genotyping of the STX17 gene for gray coat color revealed that the horse did not have the “gray” factor. The horse was euthanized ~3 mo after first presentation. During autopsy, a black-to-gray mass extended from the left nasal cavity to the surrounding paranasal sinus and invaded the hard palate, cribriform plate, and the cranial portion of the left olfactory bulb. Moreover, identical black nodules were present in lymph nodes from the mandible to the larynx, and in the spleen, liver, kidney, and adrenal glands. However, masses were not found in the skin, perineal region, or pelvic cavity. All of the black-to-gray nodules were malignant melanomas that were histologically identical to the initial biopsy; tumor emboli were also found in the kidney. Sinonasal mucosal melanoma is a rare disease in horses.

Sinonasal malignant melanoma: a case report

<p class="abstract">Primary sinonasal malignant melanoma (SNMM) is a rare aggressive neoplasm of mucosal melanoma. It is more commonly affect adult with late presentation. Here, we report a case of SNMM in a 56-year-old lady who presented with worsening left sided nasal blockage in 1-month duration associated with black pigmented mass in nasal cavity, epistaxis and diplopia. Computerized tomographic scan showed sinonasal mass with orbital involvement and tissue biopsy confirmed the diagnosis. Surgery was performed to remove the tumour and patient had recovered well with no sign of recurrence.</p><p class="abstract"> </p>

Surgery alone versus post-operative radiotherapy for sinonasal malignant melanoma: a meta-analysis

ObjectiveSinonasal malignant melanoma is a relatively rare malignancy with poor prognosis, and effective treatments remain elusive. This analysis aimed to explore whether post-operative radiotherapy conferred any survival advantages in patients with this disease when compared with surgery alone.MethodsPublished studies were identified by searching four electronic databases. The endpoints evaluated were: rates of overall survival, disease-free survival and local control.ResultsTwenty-eight studies including 1392 patients were identified. The results indicated that post-operative radiotherapy led to a significantly better three-year overall survival rate (p= 0.02), and suggested a borderline significant benefit for five-year overall survival (p= 0.05), when compared with surgery alone. However, no statistical advantage was found for disease-free survival, local control or one-year overall survival.ConclusionThis meta-analysis indicated that adjuvant radiotherapy prolonged survival, but showed no benefit for disease-free survival or local control.