Contrasting radiological presentation of cervical sympathetic chain schwannoma: case series of two cases.

Splaying of carotid bifurcation on imaging, known as Lyre sign, is seen characteristically in carotid body tumors. Is positive Lyre sign always confirmatory of carotid body tumor? Here we discuss two cases of cervical sympathetic chain schwannoma. The first case presented radiologically as an enhancing lesion with splaying of external carotid artery and internal carotid artery (positive Lyre sign) and misled us to the diagnosis of carotid body tumor. The second case presented as an enhancing lesion causing anterior displacement of external carotid artery and internal carotid artery (negative Lyre sign). Both lesions were confirmed as cervical sympathetic schwannoma. Post-operatively both patients developed Horner's syndrome. Lyre sign is not always confirmatory of carotid body tumor.