Pancoast tumours belong to a subset of lung cancers that are unique. A primary neoplasm arises from the apex of the lungs, invading the surroundings of the soft tissues. These cancers are usually not visualised on the initial chest x-ray, they are difficult to diagnose and treat. Moreover, by the time the symptoms persist, the tumour invades nearby structures.
A 58-year-old African American male patient was referred to the neurology clinic due to weakness in the upper right extremity that worsened in addition to numbness for the last nine months. He had multiple joint pains, went through a hip replacement 5 years ago and was under follow-up with orthopaedics for chronic hip pain.
He reported back pain that radiated to his right arm and felt like a burning sensation from the right shoulder to the right hand. It also caused a disturbance in his sleep at night. He described the pain as electric in quality, shooting from the right arm to the right fingertips. Moreover, he also said he had decreased strength in his right proximal region and swelling in his right hand.
Doctors did a neurological examination that showed joint stiffness, numbness in the arm, neck pain, weakness in the arm, and hands. Moreover, there was a restriction in his shoulder movement with extensive distal and proximal muscle wasting. His right arm was adducted and his forearm was rotated externally. The muscle strength of his left upper extremity was 5/5 and his right upper extremity was 2/5. Furthermore, there was impairment in abduction. Flexion of the wrist and extension of the fingers were weak.
His motor strength for the left lower and right lower extremity was 4+/5. There was a complete loss of sensation at C8-T1 distribution and a decrease in sensation in the right upper extremity. Moreover, there was gross atrophy in the thenar, lumbrical, hypothenar, and interossei muscles. He also had miosis on his right side. However, his cerebral function was normal, with fluent speech and intact cognition.
The doctors did an MRI of the cervical spine revealing a right apical mass and mild cervical spondylosis. The right shoulder MRI showed glenohumeral joint effusion and axillary region fullness, consistent with lymphadenopathy. In addition, his chest x-ray revealed extensive right upper lung bullous changes. After the pulmonary team was consulted, he went for a chest, pelvic, and abdominal CT as per their recommendation.
The chest CT showed a mass in the right apical region extending to the right supraclavicular region. CT guided biopsy of the apical mass revealed non-small cell carcinoma of the lung. Immunochemistry provided further evidence for the diagnosis of squamous cell carcinoma.
His doctors consulted the radiation and oncology team regarding the biopsy report. However, while waiting for the oncology team, the patient developed superior vena cava syndrome. he received radiations, which were reduced in dosage and continued for two weeks. There was a significant improvement in his pain after radiation but the swelling in the arm remained the same. Moreover, weaknesses also remained the same.
Since the size of the tumour was big, radiation alone did not show any effect and doctors suggested subsequent chemotherapy. Moreover, they discussed the risks and benefits.
Pancoast Tumor: Importance of Early Diagnosis
This case depicts why early diagnosis of a tumour is necessary. It should be by expanding the differential diagnosis in patients presenting with weakness, shoulder pain, and sensory loss beyond radiculopathy and diseases related to the joint. A comprehensive history leads to an earlier diagnosis and better treatment outcomes. Especially in cases of Pancoast tumours that present with musculoskeletal and neuropathic pain.
The DD of numbness and tingling can be something as small as radiculopathy from wearing a bag pack to something serious, for example, a thoracic outlet tumour. Moreover, compression of the brachial plexus can cause a tingling sensation, pain, and intrinsic hand muscle wasting.
The patient had an extensive history of joint pain, which contributed to his delayed diagnosis and referral. Moreover, regarding his other symptoms, a thorough physical examination and history would have made the diagnosis earlier. Leading to a better clinical outcome possibly. In addition, it wasn’t clear initially that his long history of multiple joint pain was in relation to carcinomatous polyarthritis.
His symptoms were consistent with brachial plexus and nearby structures involvement. It can be a challenge to diagnose a Pancoast tumour and early diagnosis can improve patient outcomes.