P27.07 Pancoast Tumour Presenting as Lower Limb Weakness; Would You Recognise It?

Abstract

Pancoast tumours were an obscure entity until Henry Pancoast first described them in the 20th century. This tumour typically involves the apical chest wall and thoracic inlet structures. To characterise a lesion as a Pancoast tumour, it must arise from the lung apices and cause neurological dysfunction. It may present as pain in the shoulder girdle and arm (along C8, T1 and T2 dermatomes), weak or atrophied hand muscles and Horner's syndrome, a constellation of symptoms collectively known as Pancoast Syndrome. These tumours that form 5 per cent of all the NSCLC (Non-small cell lung carcinoma) are often not detected early and have a high predilection for metastasis leading to an overall poor prognosis. The following clinical case study accurately describes a Pancoast tumour's signs and symptoms and emphasises the need for its early recognition by retaining a high index of suspicion even in the most routine of circumstances. A 56-year-old man presented to the emergency department with sudden onset of left leg weakness associated with mild sensory loss. Further questioning revealed clumsiness of the left hand. The initial impression was that of a stroke, but the CT head was found to be unremarkable. It was only later that examination revealed a classical Horner's syndrome; miosis, partial ptosis and hemifacial anhidrosis, raising suspicion of an apical pathology. The chest radiograph was deemed normal, and hence a CT scan of the chest was requested, which showed a left-sided Pancoast tumour. A Subsequent MRI revealed cord compression at T2-T3 levels with tumour infiltration into the left brachial plexus. CT guided biopsy confirmed lung adenocarcinoma with distant spread. He underwent five cycles of radiotherapy, during which he developed neuropathic pain, particularly along the left shoulder and upper chest. His left-sided Horner's syndrome improved clinically. The left fingers' clumsiness did not worsen, and he continued to use his left hand despite some residual weakness but permanently lost bilateral leg function due to spinal cord metastasis. This case demonstrates the significance of a thorough medical history (including smoking) and examination while assessing patients with seemingly unrelated symptoms. The presence of "normal" physical and imaging studies should provoke the clinician to think of an alternative possibility. The inability to include Pancoast tumour in the differential diagnosis most commonly causes a delay in diagnosis and management. Early recognition is the key since the prognosis is directly dependent on timely treatment, which affects patients' survival rate with lung adenocarcinoma.