Multiple interdigital neuromas: a retrospective study of 279 feet with 462 neuromas.

Morton's neuroma is a common pathologic entity that, traditionally, was considered to be an isolated tumor that rarely affected more than 1 interdigital space. However, in recent years, multiple neuromas have become more common in our day-to-day practice. The objective of the present study was to assess the frequency with which Morton's neuroma appears in the different interdigital spaces. A retrospective study was performed of 279 feet that had been surgically treated for Morton's neuroma using a dorsal approach during a 9-year period (from January 2003 to December 2011), with an ultrasound scan taken preoperatively and histopathologic analysis performed afterward. From the 279 treated feet, 462 interdigital neuromas were surgically removed. Of the 279 feet, 97 (34.8%) displayed isolated neuromas, and 182 (65.2%) were treated for multiple neuromas. Regarding the neuromas that were treated as isolated lesions, 74.2% were located in the third space. For the feet affected by multiple interdigital neuromas, 100% had a neuroma in the third space and 98.9% in the second. The incidence of multiple interdigital neuromas can be considered frequent. The assessment, therefore, of interdigital neuromas of the foot should include, at a minimum, the second and third interdigital spaces.