Solitary Orbital Metastasis in Carcinoma Esophagus: Findings on Serial 18F-FDG PET/CT Scans

The Monocle Sign in FDG-PET: A Sign of Contralateral Facial Nerve Palsy

We report three cases of unilateral F-FDG uptake in the orbicularis oculi muscle in subjects with contralateral peripheral facial nerve palsy. We argue that this asymmetric uptake pattern in fact reflects lack of metabolism on the side affected by facial nerve palsy, owing to denervation. Since the unilateral periorbital uptake resembles a monocle, we chose to call this finding the monocle sign. The monocle sign should not be confused with inflammation or tumor, but should prompt a neurological assessment for facial nerve palsy and a potential underlying disease.

Unilateral exophthalmos secondary to esophageal adenocarcinoma metastasis to the medial rectus muscle

A case is presented on a 51 year-old man with stage IV oesophageal adenocarcinoma. The patient was referred by the Oncology Department urgently for a same-day assessment by an ophthalmologist due to two weeks of severe unilateral exophthalmos and binocular diplopia. A comprehensive eye exam revealed the presence of an axial non-reductive exophthalmos and a limitation in left eye levoduction. A computed tomography scan was performed that showed a multiple lobed, intra-and extra-conal, heterogeneous left orbital mass, that surrounded the internal rectus muscle, compatible with metastasis, as well as another small extraconal mass at the base of the contralateral orbit. Palliative radiotherapy was then indicated. Metastases in the extraocular muscles are a very rare finding, but should be suspected in a case of unilateral exophthalmos and, if necessary, refer the patient to have the corresponding complementary tests performed.