Abstract
Background The appearance of dumbbell neuroma of the first thoracic root is extremely rare.
The extradural component of a T1-dumbbell neuroma may present as an apical mass. The
diagnosis of hand weakness is complex and may be delayed in T1-neuroma because of
absence of the palpable cervical mass. One-stage removal of a T1-root neuroma and
its intrathoracic extension demanded an extended posterior midline approach in the
sitting position.
Case presentation A 51-year old man had suffered a traumatic partial tendon rupture of his wrist flexor
muscles 6 years ago. Since the incident he occasionally felt fullness and tenderness
in the affected forearm with some tingling in his fingers bilaterally. During the
last two years the hand weakness was continuous and hypotrophy of the medial flexor
and intrinsic hand muscles had become apparent. Electrophysiological studies revealed
an ulnar neuropathy in addition to mild median and radial nerve dysfunction, including
a mild contralateral carpal tunnel syndrome. The diagnostic work-up for multiple mononeuropathy
in the upper extremity was negative. Repeated electrophysiological studies revealed
fibrillations in the C7 paravertebral muscles on the affected side. Chest x-ray revealed
a large round apical mass on the affected side. A Horner’s syndrome was noted at this
point of diagnostic work-up. MRI of the cervical and thoracic spine revealed a dumbbell
T1 neuroma enlarging the intervertebral foramen at T1-2 and a 5 cm large extradural
tumor with extension into the apex of the ipsilateral lung. The patient underwent
surgery in sitting position using a left dorsal midline approach. Although the T1
root could not be preserved, the patient’s neurological condition was unchanged after
the surgery.
Conclusion Extended posterior midline exposure described here using hemilaminectomy, unilateral
facetectomy and costo-transversectomy is efficient and safe for one-stage removal
of dumbbell tumors at the T1 level with a predominantly extraforaminal component in
the apex of the lung extending up to 6–7 cm laterally. Horner’s syndrome, if present
and observed, may significantly narrow the differential diagnosis of hand weakness
caused by T1-root tumors.
