A tumor in the pulmonary apex (Pancoast tumor) can invade the T1 sympathetic ganglion, causing Horner’s syndrome : ptosis, miosis, anhidrosis, and enophthalmos.
T7-T12 mediate the superficial abdominal reflexes. Loss of these reflexes can indicate a thoracic spinal cord lesion (e.g., multiple sclerosis or transverse myelitis). thoracic spine nerve
Compression of the lower trunk of the brachial plexus (C8-T1) can cause intrinsic hand muscle weakness and sensory loss along the medial arm and ulnar fingers. A tumor in the pulmonary apex (Pancoast tumor)