Metastasis of advanced gastric cancer to the extraocular muscle: a case report

BACKGROUND: Metastatic tumors in the orbit, especially from gastric cancer, are rare. We present a rare case of extraocular muscle metastasis from gastric cancer and raise consideration of metastasis to extraocular muscle as a differential diagnosis of proptosis/lid swelling in a patient with history of malignancy. CASE PRESENTATION: A 54-year-old Japanese woman presented with proptosis, lid swelling, diplopia, and retro-orbital pain in her left eye, which she had been experiencing for 1 day. She had a medical history of poorly differentiated adenocarcinoma of the stomach, which had metastasized to several organs. A computed tomography scan showed enlargement of the medial rectus muscle in her left eye. She was diagnosed as having gastric cancer metastasis to the medial rectus muscle of her left eye, and received a total of 20 Gy radiation therapy to the orbit, which resulted in resolution of her ocular symptoms. She died 3 months after her initial visit to our ophthalmic department. CONCLUSIONS: Metastasis from malignancy should be considered in the differential diagnosis of a patient presenting with proptosis or lid swelling who has a history of gastric cancer. Radiation therapy of metastases in the orbit may be an effective treatment in such cases.