Synchronously diagnosed pre-sacral neurofibroma and cutaneous spitzoid melanoma: a fortuitous association?

BACKGROUND: At a U.S prevalence of 1 in 3000, Neurofibromatosis type-1 (NF-1) is a relatively common disorder. Amongst a variety of others, occurrence of 2 or more neurofibromas in the same patient represents one of the major diagnostic criteria for this disorder. Rarely, ocular, cutaneous or anorectal malignant melanomas may be identified in patients with NF-1, This rare association has caused controversy as to whether patients with NF-1 have an inherently higher risk for melanomas or whether the associations can be explained by chance alone. CASE PRESENTATION: The purpose of this report is to highlight the unusual confluence of rare clinicopathologic features in a patient without NF-1. The patient was diagnosed with an 8.5 cm pre-sacral neurofibroma and was shortly thereafter diagnosed with a cutaneous malignant melanoma showing spitzoid features. Pre-sacral neurofibromas are rare in patients without NF-1; likewise, malignant spitzoid melanoma, a controversial histopathological entity, is distinctly uncommon. CONCLUSIONS: The synchronous diagnoses of these neural crest derived tumor entities in a patient without neurofibromatosis lends credence to the view that when these two lesions occur in patients with NF-1, the association is coincidental.