Ultrasonography of peripheral nerve tumours: a case series

Peripheral nerve tumours (PNTs) are rare, but important cause of peripheral nerve dysfunction. The aim of the study was to present a series of consecutive patients with PNTs evaluated in authors' ultrasonography (US) practice.

The electronic medical records of patients with PNTs examined at our US laboratory from February 2013 to May 2020 were retrospectively reviewed. Data on gender, age, clinical features, PNT location, electrodiagnostic (EDx) features and US findings were collected.

In the analyzed period 2845 patients were examined in our US laboratory. From these 15 patients (0.5%) with PNTs were identified. Four of them (3 with confirmed neurofibromatosis) had multiple PNTs. Half of patients (53%) presented with features of peripheral nerve damage, and others with palpable mass or pain. The most often involved nerve was ulnar (36%). PNT cross sectional areas varied from 24 mm² to 1250 mm² (median, 61 mm²). Based in 5 patients on histological and in remaining patients on US features, schwannoma was diagnosed in 40%, neurofibroma in 27%, and perineurioma in 27% of patients.

As in previous reports, PNTs in our series presented with neurological symptoms, palpable mass or pain. In contrast to other focal neuropathies, particularly nerves with schwannomas, in spite of their large thickening, often demonstrated well preserved function. Adding US to our clinical practice, enabled us to diagnose these rare peripheral nerve lesions that we missed before.