Primary mucosal desmoplastic melanoma of the nasal vestibule: the second case.

Primary mucosal desmoplastic melanoma is an exceedingly rare, potentially devastating disease that is often initially misdiagnosed because of its deceptively benign presentation. We report what we believe is only the second case of mucosal desmoplastic melanoma arising from the nasal vestibule. The patient, a 62-year-old woman, presented with an obstructive, enlarging mass in the nasal cavity. The tumor, which was initially believed to be benign, was excised, but it recurred 12 months postoperatively. The recurrence was excised, but 4 years later, the patient experienced a second recurrence; in this case, the tumor had invaded the cribriform plate and extended to the anterior cranial fossa. The tumor subsequently metastasized to the dura mater, which led to the patient's death. We review the distinction between conventional mucosal melanoma and mucosal desmoplastic melanoma, and we discuss the ways in which the behavior of a desmoplastic melanoma can point to the diagnosis. Because a diagnosis can be difficult to establish, we stress the importance of maintaining a high index of suspicion when evaluating pathologic and immunohistochemical findings in a patient with a recurrent mucosal nasal mass.