Percutaneous or Open Surgical Biopsy in a Case of Symptomatic Neoplastic Brachial Plexus Infiltration?

Introduction

Symptoms related to lesions of the peripheral nervous system (PNS) may be the initial clinical manifestation of a previously unknown tumor, arising from either the nerve tissue (e. g., schwannoma) or – more common – from non-neurogenic structures, such as lung cancer in pancoast tumors, metastatic lymph node infiltrations or lymphomas.

Percutaneous biopsy obtained from tumors presenting with symptomatic lesions of the PNS may include the risk of causing or worsening of neurological impairment and neuropathic pain due to needle trauma Stöhr M. Nervenläsionen durch Injektion und Punktion. In: Stöhr M. Iatrogene Nervenläsionen. Georg Thieme Verlag; Stuttgart New York: 1996; Horowitz SH. Neurology 1994; 44: 962–964.

Compared to needles for injections, biopsy needles (e. g., high-speed thru-cut biopsy systems) are larger in diameter (mostly in the range of 14–18 Gauge with a core diameter of about 2 mm), thus the tissue volume exposed to needle trauma is much more extended. Anatomical studies show that diameters of the trunci converging to the brachial nerve plexus (truncus sup. mean 6.7 mm, range 4.1–9 mm, truncus med. mean 4.99 mm, range 3.8–8 mm and truncus inf. mean 6.68 mm, range 3.7–9 mm) are significantly larger than core diameters of biopsy needles Lang J. Klinische Anatomie der Halswirbelsäule. Georg Thieme Verlag; Stuttgart New York: 1991. The risk for neurological impairment is particularily high in core biopsy needle trauma when such nerves are afflicted which consist of large nerve fascicles, surrounded by small layers of epidural tissue Selander D, Sjöstrand J. Acta anaesthesiol scand 1978; 23: 622 and it has to be assumed, that altered mechanical properties of nerves affected by neoplastic infiltration, dislocation and compression may increase the risk for core biopsy needle trauma too. Furthermore, neuropathic pain following nerve trauma is more common in nerves containing a high proportion of somatosensory and autonomic nerve fibers, resp., like the median and tibial nerves.