A cluster of signs and symptoms that include (1) upper extremity or shoulder pain, (2) Horner’s syndrome, and (3) atrophy of muscle or bone of the affected arm. It almost always is caused by a malignant neoplasm invading the brachial plexus and cervical sympathetic nerves. Rarely, it results from a tubercular or fungal infection of the same nerves.
A set of symptoms arise when a growth impinges on the brachial plexus, the primary nerve cluster governing the arm and hand. These symptoms encompass pain and paralysis in the arm or hand. If the growth affects the sympathetic cervical (neck) nerves, Horner’s syndrome may also manifest. This condition, known as Pancoast’s syndrome, is often attributed to a specific tumor called Pancoast’s tumor, which forms in the lung’s upper region, typically in those with lung cancer.