A Nearly Missed Pancoast Tumour From Isolated Persistent Leg Pain.

Pancoast tumours (PTs) are apical tumours of the lung that manifest with a variety of symptoms. Herein, we describe a rare case of a 56-year-old female with a one-month history of persistent left leg pain despite advanced imaging, such as magnetic resonance imaging (MRI), and orthopaedic input, which was focused onto her left knee being the prime cause of her pain. Her non-resolving symptoms prompted her to attend the Emergency Department. A careful clinical examination pointed towards the left proximal tibia being the most probable cause. Basic radiographic imaging (x-ray) of the left tibia revealed a lytic lesion which was later confirmed to be metastatic disease arising from a Pancoast tumour (PT) following further advanced imaging and diagnostics. This case highlights a unique presentation of a Pancoast tumour that, to our knowledge, has never been reported before in the medical literature. A high index of suspicion, careful examination, and investigation were essential to reach this diagnosis.