Background: Mucosal melanoma is quite rare in comparison to primary cutaneous melanoma, accounting for 1.3% of all melanoma cases. The majority of mucosal melanoma cases (~55%) occur in the head and neck with nearly all of the cases being sinonasal in origin. The first reported case of middle ear melanoma was in 1981. Since then, there have been eight additional reported cases of this extremely rare disease process. This study will present the case of a 17-year old female with middle ear and middle cranial fossa melanoma who underwent resection via a staged middle cranial fossa and transtemporal approaches.
Design: Case report with review of literature.
Results: An otherwise healthy 17-year old female developed sudden-onset severe headache with staring spells and lip-smacking behavior. She was brought urgently to the emergency department, where a non-contrast head CT demonstrated a homogenous left temporal region mass. There was initial concern for an intraparenchymal hemorrhage or thrombosed aneurysm, hence cerebral angiography was performed. This demonstrated an extra-axial left temporal lobe mass. The following day she underwent middle fossa craniotomy for subtemporal approach to the left temporal lobe lesion with resection of the extra-axial lesion. At surgery the lesion appeared to arise from the middle cranial fossa floor. Tumor extending into the temporal bone was left in situ. Pathology reports demonstrated malignant melanoma. She subsequently underwent left post-auricular transmastoid approach to the lateral skull base for resection of extradural temporal bone melanoma. At this second surgery, clumps of hyperpigmented cells could seen within the middle ear mucosa under the operating microscope. Following this two stage resection, she has received adjuvant chemotherapy and radiation therapy. She has been monitored with serial MR imaging and has no evidence of recurrent or metastatic disease over three years following her initial presentation.
Conclusion: This is the youngest reported case of primary mucosal middle ear melanoma in the literature. The patient underwent initial neurosurgery approach to removal of left temporal lobe tumor and resection of extra-axial lesion from a subtemporal approach. She later underwent transmastoid approach to resection of extradural temporal bone remnant disease. Her course has been complicated by infected bone plate, radiation-induced cerebral necrosis, as well as iatrogenic epilepsy. However, she remains clinically and radiographically free of disease at 3 years from her initial presentation. From our literature review, common presenting symptoms include aural fullness, otorrhea, as well as hearing loss. Patients may also present with primary neurologic complaints. Typical treatment course is surgery followed by adjuvant radiation for resectable tumors, otherwise patients receive chemotherapy. Four out of 8 patients with reported outcomes were deceased within 18 months of diagnosis. Mucosal middle ear melanoma is an aggressive disease with variable presentation; surgical resection and reconstruction can require multiple stages and a multidisciplinary approach with neurosurgery and neurotology.
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