Case 3: brachial plexus tumor

posted: 5/14/96

Resident: Ian Angel, MD
Attending Staff: Robert Tiel, MD

The patient is a 45 year old right handed female in whom a left apical lung mass was incidentally discovered on chest X-ray (see below) during an evaluation for pneumonia. Retrospectively she had noted shooting pains that would go down the arm and into the hand.

PHYSICAL EXAMINATION: On inspection of her neck a slight fullness on the left side was appreciated in comparison to the right side. Gentle tapping on the left side of the neck generated a Tinel's sign going down into her fifth finger. Her only weakness was mild 4+/5 weakness of the fourth and fifth lumbricals and the left adductor digiti quinti muscle. Her sensation was intact.

RADIOLOGICAL EXAMINATION: Her preoperative radiological evaluation consisted of plain X-rays of the chest:

note the apical shadow (red marker) on the left
and a MRI with gadolinium contrast:

Here a mass measuring 3 centimeters in diameter appeared just above the left lung apex it tracked back to the left C 7-T1 neural foramina. It showed mixed contrast enhancement and abnormal signal intensity. It did not extend into the spinal canal.

How would you proceed at this point? What approach would you take to resect this tumor- Anterior vs. Posterior?

Please comment: AwasBrainS@aol.com

STEPS TAKEN AT LSU: She was taken to the operating room and via the posterior approach the trunks of the brachial plexus were exposed. This required that the trapezius , rhomboids and levator scapulae muscles be divided, and the scapula retracted. The first rib was removed to its origin. Then the posterior and middle scalene muscles were removed in a piecemeal fashion . This allowed exposure of the brachial plexus at a trunk level.

Intraoperative view (posterior approach): T: tumor (overlying the C8 and T1 roots; originating from C8 root); green: middle trunk from C7 root; yellow: C6 root extending into upper trunk; blue: C5 root; note: 1st rib has been resected. The lower trunk was mobilized. The capsule of the tumor was incised and a partial debulking initially achieved. This allowed exposure of the C-8 and T-1 nerve roots. This action facilitated further tumor removal and dissection of the capsule wall from these nerve roots. After the tumor was removed the muscle layers were re-approximated and the incision closed.

She did well, on the first postoperative day in addition to her preoperative weakness there was 4+/5 weakness of flexor digitorum profundus, digits four and five. Furthermore there was numbness of the fourth and fifth fingers with mild paresthesias. By six weeks she returned to her baseline examination with respect to motor functioning and reported only slight numbness in the fourth and fifth fingers with infrequent paresthesias. She had no scapula winging on examination.

PATHOLOGY: Benign schwannoma (C8 root origin)

References

1. Kline DG and Hudson A: Tumors involving nerve, in Nerve Injuries: Operative Results for Major Nerve Injuries, Entrapments and Tumors. Philadelphia: WB Saunders, Co., 1995, pp525-574; note: please refer to pages 525-574 of this chapter for "Brachial plexus tumors operated on by a posterior subscapular approach.".
2. Kline DG, Donner TR, Happel L, Smith B, Richter HP: Intraforaminal repair of plexus spinal nerves by a posterior approach: An experimental study. J Neurosurg 76:459-470, 1992 - this is an experimental study using a primate model .
3. Lusk MD, Kline DG, Garcia CA: Tumors of brachial plexus. Neurosurgery 21:439-453, 1987.
4. Kline DG, Kott J, Barnes G, Bryant L: Exploration of selected brachial plexus lesions by the posterior subscapular approach.. J Neurosurgery 49:872-880, 1978.

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