Pancoast tumor
Meaning of Pancoast tumor: A Pancoast tumor is a lung cancer at the lung's apex that can invade nearby nerves, causing distinctive shoulder and arm symptoms.
Definition of Pancoast tumor
A Pancoast tumor is a cancer that develops at the very top of a lung and grows into nearby structures, including the ribs, vertebrae, and the network of nerves that supplies the arm, known as the brachial plexus. Most Pancoast tumors are non-small cell lung cancers, the more common broad category of lung cancer.
Because of its location, a Pancoast tumor often produces a distinctive pattern of symptoms not typical of lung cancer elsewhere in the lung, including persistent shoulder and arm pain from nerve involvement and, when the tumor affects the sympathetic nerve chain running through the chest, a combination of a drooping eyelid, a constricted pupil, and reduced sweating on the affected side of the face, together called Horner syndrome.
Because these symptoms can resemble a shoulder or nerve problem unrelated to the lungs, a Pancoast tumor is sometimes not recognized until it has already grown large enough to involve these nearby structures.
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Used in a sentence
Imaging revealed a Pancoast tumor invading the chest wall in the patient with persistent shoulder pain.
Good to know
A Pancoast tumor can cause shoulder and arm pain resembling a musculoskeletal problem before any typical respiratory symptom appears, a pattern that can delay recognition of its underlying pulmonary origin.