RESUMO
INTRODUCTION: Desmoplastic melanoma (DM) arising in the oral cavity is a rare neoplasm that may be confused with a variety of non-melanocytic benign or malignant lesions. OBJECTIVES: To present a case of DM in the oral mucosa mimicking fibrous inflammatory hyperplasia, discusses the difficulties involved in the diagnosis and offers a literature review on the clinicopathologic and immunohistochemincal aspects of this neoplasm. CASE REPORT: A 62-year-old white male, smoker, was referred with a chief complaint of pain and swelling in the palate. The oral examination revealed multiple brown-to-black patches and a non-pigmented sessile nodule located on the mucosa of the hard palate. The clinical diagnosis of the pigmented lesions was either oral melanosis or melanoma. The nodular lesion was clinically diagnosed as fibrous inflammatory hyperplasia. Incisional biopsy was performed on the pigmented lesion and the microscopic sections revealed a melanotic macule. The nodular lesions histologically revealed an amelanotic desmoplastic melanoma. CONCLUSIONS: Reactive lesions close to a pigmented area should be investigated with great care.