Lipomas as an Extremely Rare Cause for Brachial Plexus Compression: A Case Series and Systematic Review

Brachial Plexus Lipoma Causing Neurological Impairment: A Case Series and Systematic Review

BACKGROUND AND OBJECTIVES

Lipomas are benign adipocyte tumors that typically present as painless, firm nodules. In rare cases, lipomas may grow near the brachial plexus (BP) and compress various peripheral nerves. This can manifest as upper extremity motor and/or sensory deficits, numbness, tingling, or burning sensations. Surgical intervention of a brachial plexus lipoma (BPL) may be challenging because of variability in location and size. This study reviews previously reported cases of BPL causing neurological impairment and presents 5 additional cases, focusing on operative details and patient outcomes.

METHODS

A systematic review of PubMed, Scopus, and World of Science was performed to identify all previously reported cases of BP lipomas resulting in neurological deficit. A retrospective review of a neurosurgeon's prospectively collected database was conducted to identify all patients operated on for BPL. Patient demographics, tumor characteristics, presentation, surgical notes, and outcomes were collected for both reviews.

RESULTS

Our literature review yielded 13 articles presenting at least one case meeting the eligibility criteria, resulting in 22 eligible patients. The surgeon's database provided an additional 5 patients meeting the criteria. Of the 27 total cases, 15 were men and 12 were women. The average age was 46.5 with a range of 25 to 70. All patients had upper extremity motor and/or sensory dysfunction preoperatively. Tumors were found in various regions, with the involvement of the supraclavicular fossa reported in 52% of cases. Gross tumor resection was achieved in all but 2 of the 27 operations. Four patients had a nonconventional lipoma type on histology. Sixteen patients experienced complete resolution of neurological symptoms.

CONCLUSION

BP lipomas are rare but can cause a wide range of neurological symptoms depending on their size and location. A thorough patient examination and imaging studies are essential for creating a successful surgical plan for tumor resection.

Lipomatous Mass Effect on the Brachial Plexus: A Case Report

Peripheral nerve compression is a prevalent concern for primary care physicians and hand surgeons, with carpal tunnel syndrome (CTS) and median nerve compression at the wrist being some of the most commonly diagnosed conditions. However, for less common nerve entrapment syndromes, it is crucial for healthcare providers to recognize their symptoms and consider potential underlying issues, particularly those related to the brachial plexus. This case report highlights a 57-year-old male who presented with classic symptoms of left median and ulnar nerve compression in the setting of an enlarging left axillary mass. The patient, a right-hand-dominant male, reported numbness and tingling in the left ulnar-sided digits, as well as weakness in small and ring finger flexion, which began after a fall onto his elbow and outstretched hand a year prior. Initially, the patient experienced significant numbness, tingling, and pain radiating up to the shoulder. Weakness in hand grip, especially affecting the small and ring fingers, and thumb abduction and opposition were also noted. The patient reported transient symptomatic relief with shoulder abduction. Over time, his median nerve compression symptoms improved, with only mild residual tingling noted with shoulder adduction and compression of the axillary mass. However, his ulnar nerve compression symptoms showed minimal improvement despite occupational therapy. The patient had a history of a left axillary lipoma identified five years earlier, which had not been surgically treated, aside from an incisional biopsy that confirmed the pathology. Upon examination, the patient presented with a 7 cm × 10 cm, well-circumscribed, deeply adherent mass in the left axilla. Clinical findings included a positive Wartenberg's sign of the left small finger, decreased strength in small and ring finger flexion compared to the right, and impaired two-point discrimination of the small and ring fingers. A positive Tinel's sign was noted at the left cubital tunnel, while the carpal tunnel and Guyon's canal were negative. Electromyography revealed left-sided ulnar and median nerve compression at the cubital tunnel and carpal tunnel, but could not exclude brachial plexopathy. MRI of the left brachial plexus revealed the lipoma exerting mass effect on the brachial plexus cords and branches, as well as the left axillary vasculature. Surgical intervention involved excision of the left axillary lipoma, brachial plexus exploration and neurolysis, and cubital tunnel release with anterior transposition. Three lipomatous masses were identified, intertwined with the brachial plexus divisions and cords and the axillary vasculature. Meticulous dissection with 3.5× loupe magnification was performed to decompress the brachial plexus. At the six-month follow-up, the patient's symptoms had completely resolved, and he returned to full activity. This case underscores the importance of evaluating and ruling out brachial plexus pathology in patients presenting with peripheral nerve compression symptoms.

Complete encasement of the radial nerve by a giant lipoma: illustrative case

BACKGROUND

Among the spectrum of adipose lesions associated with peripheral nerves, complete circumferential encasement of the nerve by the lesion is a very rare entity. The authors report the first case of a giant lipoma that completely and circumferentially encased the radial nerve.

OBSERVATIONS

A 57-year-old woman presented with a large left-arm mass that she had noticed over a year following significant weight loss. She had hypersensitivity and dysesthesias in the left posterior arm but no weakness or other symptoms. Magnetic resonance imaging of the left upper limb demonstrated a large lipoma completely encasing the radial nerve, originating at the level of the spiral grove proximally and extending distally to the lateral epicondyle. The lesion was completely resected at surgery with total preservation of radial nerve function.

LESSONS

Lipomas encasing peripheral nerves can be difficult to manage while preserving function. This case adds to the intriguing spectrum of adipose lesions associated with peripheral nerves. https://thejns.org/doi/10.3171/CASE24148.

The Utility of Intraoperative Neuromonitoring in Pediatric Surgical Oncology

BACKGROUND

Intraoperative nerve monitoring (IONM) is a technique used to decrease the possibility of nerve-associated morbidity and damage to nearby neural structures during complex surgical procedures. The use and potential benefits of IONM in pediatric surgical oncology are not well-described.

METHODS

An overview of the current literature was performed to elucidate the various techniques that may be useful to pediatric surgeons for resection of solid tumors in children.

RESULTS

The physiology and common types of IONM relevant to the pediatric surgeon are described. Important anesthetic considerations are reviewed. Specific applications for IONM that may be useful in pediatric surgical oncology are then summarized, including its use for monitoring the recurrent laryngeal nerve, the facial nerve, the brachial plexus, spinal nerves, and lower extremity nerves. Troubleshooting techniques regarding common pitfalls are then proposed.

CONCLUSION

IONM is a technique that may be beneficial in pediatric surgical oncology to minimize nerve injury during extensive tumor resections. This review aimed to elucidate the various techniques available. IONM should be considered as an adjunct for the safe resection of solid tumors in children in the proper setting with the appropriate level of expertise. A multidisciplinary approach is advised. Additional studies are necessary to further clarify the optimal use and outcomes in this patient population.

LEVELS OF EVIDENCE

Level III.

Upper extremity mass with lipomatous axillary involvement and multiple level encasement of the brachial plexus

A 40-year-old female presented for surgical consultation of an upper extremity soft tissue mass. Initial ultrasound report recorded a 5.5 cm mass, consistent with a subcutaneous lipoma. Intra-operative visualization revealed an intramuscular lipoma emerging from brachialis muscle. Post-excision MRI was ordered for continued axillary fullness which revealed lipomatous extension into axilla and posterior arm with multiple level encasement of the brachial plexus. Lipomas with brachial plexus involvement are rare and can present with a range of symptoms and distortion of local anatomy. Surgical debulking is challenging requiring microsurgical expertise for adequate removal and to minimize long-term neurological deficits.