Periocular Desmoplastic Malignant Melanoma and Orbital Invasion With Uncontrollable Disease: A Case Report.

Primary orbital melanoma and metastatic cutaneous melanoma of the orbit are extremely rare. Desmoplastic melanoma (DM) is an infrequent variant of melanoma that can extend from a superficial location into deep tissues by neurotropic mechanisms. A 78-year-old male was referred to us with a periocular mixed malignant melanoma (spindle cell melanoma with desmoplastic reaction) in his left lower eyelid with uncontrollable disease (orbital and inferior orbital rim invasion) despite treatment. The surgical technique consisted of an extended orbital exenteration, maxillectomy, and ethmoidectomy, with a 2 cm macroscopic surgical margin. We performed a delayed socket reconstruction with a temporalis muscle flap using a transorbital approach. The patient remained disease-free for 1.5 years with a good quality of life since exenteration surgery. At this time, he presented a recurrence in the area of the malar scar with a new orbital invasion, and finally, he died due to mediastinal, pleural, and pulmonary metastasis. The treatment of a cutaneous melanoma arising in the periocular region is a challenging reconstructive problem and it may compromise the globe and visual function.