Is Histopathological Analysis of Interdigital Morton's Neuroma Necessary?

BACKGROUND: Interdigital neuroma (IN), otherwise known as Morton's neuroma, is a common cause of metatarsalgia presenting to the elective foot and ankle clinic. Surgical excision of the IN in patients who fail to respond to nonoperative measures is considered to be the gold standard of care in many centers. The Royal College of Pathologists UK recommend that all excised interdigital Morton's neuromas are sent for formal histopathological analysis. We present a study correlating clinical and radiological diagnosis with histopathologic appearances of IN following surgical excision, and question if routine histopathological analysis is warranted.

METHODS: A retrospective study was carried out in a single center. Ninety-six operative records were reviewed to identify all the cases of IN surgically resected between January 2007 and July 2016. The histopathology result of the resected IN specimen, that had a clinical and radiological diagnosis of IN, was analyzed.

RESULTS: A total of 85 patients met the inclusion criteria and were included in the final analysis. We found that 100% of patients with a clinical, radiographic, and intraoperative diagnosis of a Morton's neuroma had a histopathological report confirming a Morton's interdigital neuroma.

CONCLUSION: In our single-surgeon series, histopathologic diagnosis is in complete agreement with clinical and radiological diagnosis. We therefore recommend that routine histopathological analysis of IN is not necessary, saving resources and providing a cost benefit. Histopathologic examination should be reserved only in cases where intraoperative findings do not concur with clinical and radiological features.

LEVELS OF EVIDENCE: Level IV: Case series.