Contralateral Horner’s Syndrome as the Initial Manifestation of Perihilar Small Cell Lung Cancer from Nodal Compression

Horner’s syndrome is traditionally associated with superior sulcus (Pancoast) tumours, although disruption of the oculosympathetic pathway may occur at multiple anatomical levels and may be the presenting feature of serious underlying pathology. In this case, a left perihilar SCLC was associated with a contralateral Horner’s syndrome due to suspected compression of the sympathetic chain from a nodal conglomerate abutting the right subclavian artery and common carotid. Primary detection of Horner’s syndrome remains uncommon, as most cases are only identified after an underlying diagnosis has already been established.