Acute monocular blindness resulting from transformation of von Recklinghausen's neurofibromatosis to malignant melanocytic schwannomas.

A 59-year-old male was transferred to our facility after initial workup for left eye blindness revealed multiple brain lesions. The patient presented with scant pedunculated skin lesions on his neck and arms, axillary freckling and bilateral subcutaneous ankle nodules suggestive of neurofibromatosis type 1 (NF-1). Neurological examination revealed left-sided blindness, diminished pupillary response to light, incomplete eyelid closure and facial droop. A CT series of the chest/abdomen/pelvis demonstrated several lesions in the lungs, liver and left kidney. CT-guided biopsy of the renal lesion was "consistent with metastatic melanoma" based on the presence of malignant cell staining for the melanocyte differentiation antigen MART-1, as well as the calcium binding protein S-100. A dermatology consultant confirmed neurofibromas and a café au lait macule. No dysplastic nevi or primary melanoma were identified. An ophthalmology consultant noted gray choroidal lesions on fundoscopic examination thought to be metastatic disease of unknown primary. Despite treatment with whole brain irradiation and intravenous steroids, the patient died on hospital day 10. A full autopsy showed diffuse neurofibromas and café au lait macules consistent with NF-1 and malignant melanocytic schwannomas with multiple metastases.