History: 39 year old woman with forefoot pain
Findings: There is an 11x3mm tear-drop shape well defined low intensity mass in the 3rd intermetatarsal space, consistent with Morton(‘s) neuroma (aka. Perineural Fibroma). The patient was subsequently operated on, and the mass was pathology proved perneural fibrosis.
Discussion: Morton neuroma is a non-neoplastic entrapment syndrome of the common digital nerve, typically in the 2nd or 3rd intermetatarsalspace. Mass-like enlargement of the nerve occurs due to perineural fibrosis. Patient’s present with localized pain in the forefoot.
In our experience, MRI is the preferred method of evaluation in the evaluation of metatarsalgia. Although MRI and ultrasound have a comparable diagnostic efficacy for Morton Neuroma, MRI is better able to evaluate for the most common differential diagnoses of forefoot pain including intermetatarsal bursitis, stress fracture, arthrosis, osteomyelitis, true neoplasm, etc…