Orbital leiomyosarcoma metastasis presenting prior to diagnosis of the primary tumor

Abstract

SummaryLeiomyosarcomas, neoplasms of smooth muscle, are rarely found within the orbit. Orbital leiomyosarcoma may be primary, metastatic, or secondary to radiation. When they are metastatic, patients almost exclusively have a history of a primary leiomyosarcoma, often occurring in the spermatic cord, skin, gastrointestinal tract, or the uterus. We present the case of 48-year-old woman who presented with a metastatic orbital leiomyosarcoma, which was identified before the primary tumor. Case ReportA 48-year-old woman with a history of primary openangle glaucoma presented at Massachusetts Eye and Ear with binocular, horizontal diplopia, intermittent left retrobulbar pain, and mild discomfort of the left eye with eye movement. The patient complained of a 4-month history of hypoesthesia of the left cheek, which she associated to apparent nerve injury from ipsilateral injection of a local anesthetic for a root canal performed just prior to onset of symptoms. The patient's visual acuity was 20/15 in each eye, with slight dyschromatopsia in both eyes. She had a superior arcuate visual field defect in the left eye secondary to glaucoma ( Figure 1A). There was 1 mm of proptosis and limitation of abduction of the left eye resulting in an incomitant esotropia larger in left gaze. Magnetic resonance imaging (MRI) demonstrated a well circumscribed lesion in the left orbital apex that appeared inseparable from the left lateral rectus muscle; the lesion enhanced slightly less than muscle, with more prominent enhancement of the rim of the lesion (Figure 2).Given that the lesion appeared intrinsic to the extraocular muscle, a common site to harbor an orbital metastasis, the patient underwent a systemic work-up searching for an occult primary malignancy. An 18-fluorodeoxyglucose positron emission tomography (18-FDG PET) scan showed a right lower quadrant mass that was lobulated and heterogeneously enhancing with 18-FDG avidity in the pelvis demonstrating its hypermetabolic nature (Figure 3).A radiologically guided core needle biopsy was performed of the mass. The pathology demonstrated eosinophilic spindle-shaped cells with elongated nuclei, scattered mitotic figures, and areas of ischemic degeneration. The lesion stained positive for both desmin and smooth muscle actin, in keeping with a malignant smooth muscle neoplasm, specifically a leiomyosarcoma (Figure 4). Systemic chemotherapy was being considered for management of her metastatic disease when the patient developed worsening retrobulbar pain (2 months after initial presentation). On examination, her visual acuity was reduced to 20/25, and there was notable worsening of the dyschromatopsia and visual field defect in the left eye ( Figure 1B). In addition, she had further limitation of abduction of the left eye. Repeat MRI scan demonstrated enlargement of the lesion, with compression of the left optic nerve laterally ( Figure 5). In order

Leiomyosarcoma with Isolated Metastasis to the Extraocular Muscle: A Case Report involving Whole-Exome Sequencing

“…Among these previously reported cases, only two have involved extraocular muscle invasion. 3,5 Metastatic orbital leiomyosarcomas demonstrate a more diffuse enhancement than primary orbital leiomyosarcomas, which are isointense to the extraocular muscle on T1-weighted MRI and have notable peripheral rim enhancement. 9 However, MRI ndings of metastatic orbital leiomyosarcoma have varied across cases.…”

“…2 Leiomyosarcoma of the orbit, metastatic or primary, has rarely been reported. [3][4][5] Moreover, to our knowledge, the diagnosis and clinical course of metastatic orbital leiomyosarcoma, involving assessments using next-generation sequencing (NGS), have not been reported. Here, we present a case of metastatic leiomyosarcoma, rst presenting with symptoms in the orbital area, in which NGS was performed to evaluate common cancer-associated genes.…”