Dermoid cysts are rare, benign congenital tumors that develop due to abnormal fusion of ectodermal and mesodermal cell lines. On histology, these growths are lined by stratified squamous epithelial cells and typically contain adnexal structures including sebaceous glands, sweat glands, and hair follicles, which can help distinguish them from epidermoid cysts.

Mucosal melanoma is a rare and extremely aggressive malignancy, distinct from other melanomas. Melanocytes, though abundant in the skin, can also be found in the mucous membrane.