Morton's intermetatarsal neuroma: morphology and histological substrate

Area of Science:

• Podiatry
• Histopathology
• Surgical Pathology

Background:

• Intermetatarsal neuroma, commonly known as Morton's metatarsalgia, is a frequent cause of forefoot pain.
• Histological examination is considered the gold standard for diagnosing intermetatarsal neuroma.
• The necessity of advanced imaging and postoperative histological analysis warrants further investigation.

Purpose of the Study:

• To compare the histomorphological and semi-quantitative features of nerves from patients with Morton's metatarsalgia to those from autopsy specimens.
• To evaluate the diagnostic value of postoperative histological examination.
• To assess the utility of diagnostic imaging modalities like MRI and ultrasonography in surgical decision-making.

Main Methods:

• Histological and semi-quantitative analysis of 23 nerve biopsies from symptomatic patients.
• Comparison with 25 plantar nerves from the intermetatarsal space III/IV obtained from autopsies of individuals without forefoot problems.
• Assessment of nerve diameter and qualitative histomorphological features.

Main Results:

• No qualitative histological differences were observed between nerves from symptomatic patients and autopsy specimens.
• Nerves from symptomatic patients tended to have larger diameters than those from autopsies, though overlap existed.
• The study reported a specificity of 80% and sensitivity of 78% for nerve swelling.

Conclusions:

• Histomorphological findings in Morton's metatarsalgia are not distinct from normal nerves, questioning the value of postoperative histology.
• Diagnostic imaging (MRI, ultrasonography) is not superior to local anesthesia for surgical decision-making.
• The diagnostic confirmation of intermetatarsal neuroma relies on clinical presentation rather than solely on histological findings.