Melanoma metastasis in the petrous bone

Background:

Tumors of the temporal bone are so rare that no relevant epidemiological data are available. Among the epithelial malignancies, the most common in this location are adenocarcinomas and squamous cell carcinomas.

Case report:

A 60-year-old man presented with right-sided otalgia for a few days and an ipsilateral facial paralysis since the previous day. Otorrhea and dizziness were not present. The microscopic examination of the ears was normal, the facial paralysis could be assigned to grade IV according to House and Brackmann. MRI revealed tumorous mass of the mastoid with infiltration of the dura and sigmoid sinus. The subsequently induced CT scan showed concomitant mastoiditis with bony destruction.

Therapeutically, after intravenous antibiotics and high-dose steroid infusions a modified mastoidectomy and a tympanic drainage were performed. Intraoperatively, a dark-tinged tumor with skull base erosion and partially exposed dura mater was present. The rapid section examination revealed the cell picture of a malignant melanoma which was positive for melanin, S-100, Ki-67 and HMB45 in the definitive diagnosis. In gene sequencing, a BRAF wild type was obtained.

Discussion:

Mucosal melanomas are rare, but there are only very isolated case reports of the temporal bone. Since the patient's history of a treated, last recurrence-free malignant melanoma was already known in the right nasal cavity, a dissemination in the petrous bone is assumed. In addition to the operative rehabilitation, the induction of specific immunotherapy is the treatment of choice, which has also contributed to a relapse-free period of about 6 months in our patient on nivolumab and ipilimumab in conjunction with radiotherapy.

Publication History

Publication Date:
18 April 2018 (online)