Description: Focal mucosal melanosis (intramucosal dendritic melanocytes without atypia) with pigmentation incontinence and small centres of subepithelial melanoma infiltrations.Additional finding: In addition to the focal melanosis, there also are subepithelial infiltrations of spindle-shaped melanoma cells, which express the melanocytic markers S-100 and Pan-Melanoma (HMB-45, Melan-A and tyrosinase). A mucosal melanosis can also be observed in the region of the likewise biopsied mucosa of the maxillary sinus.Cinical history: 70 year old female patient with melanoma in the ethmoidal region. Suspected recurrence of the melanoma (primary diagnosis 2 years ago). The picture shows a biopsy speciman (200fold enhancement) of the region of the nasal concha.Comment: Malignant melanoma of the sinus mucosa tend to metastasize in multiple centres, mostly unilaterally, under the development of intramucosal and invasive tumor parts, sometimes several centimetres away from the primary tumor. Also in this patient, one can find multicentric foci of a mucosal melanosis. This usually can be considered as pre-neoplasia in such patients, even if distinctive cytologic atypias of the intramucosal melanocytes are missing. Therefore, literature reccomends to remove the complete ipsilateral nasal and paranasal sinus mucosa in sinonasal melanomas (and thereby, the multicenter foci of melanoma thatlead to local recurrence, too). Additionally, a postoperative radiotherapy is recommended. Reference: ANZ J Surg 2005; 75 (4): 192-197. Experience with Mucosae Melanoma of the Nose and Paranasal Sinuses. Bridger AG. et al.Source: ©PathoPic
