Orbital myxoma: A case report

Abstract

Background: Myxomas are rare, locally infiltrative, benign neoplasms of mesenchymal origin. Although benign, these tumors are locally aggressive with a high rate of recurrence following conservative resection. Their relative infrequency, variable location, and insidious growth present a diagnostic challenge to clinicians. Cases of myxomas have been described throughout the body, but intraosseous myxomas of the orbit are exceedingly rare.

Case description: We report a case of a 53-year-old male with a history of chronic sinusitis and symptoms of hyposmia and bifrontal headaches refractory medical management who presented for neurosurgical evaluation after radiographic findings of an orbital lesion. Physical examination was unremarkable with intact extraocular movements. Prior radiographic workup demonstrated a 2.4 × 2.7 × 2.2 cm expansile lesion involving the bony left superior and lateral orbit. A prior open biopsy was performed which demonstrated a low-grade spindle cell neoplasm consistent with intraosseous myxoma. Definitive resection was recommended through the left orbitozygomatic craniotomy. The patient tolerated the procedure well without complications. Gross total resection was achieved. Reconstruction of the orbital roof and lateral orbital wall was performed with a frontal bone autograft and titanium plating. Postoperative course was uneventful, and the patient was discharged home postoperative day 2. At 1-month follow-up visit, the patient remained neurologically intact. Surveillance imaging at 6 months and 1 year remained stable without signs of recurrence.

Conclusion: Intraosseous orbital myxomas are exceedingly rare entities. Although they are considered benign neoplasms, myxomas demonstrate high recurrence rates. The authors report a unique case of an orbital myxoma that was successfully treated through an orbitozygomatic approach achieving gross total resection.

Keywords: Intraosseous; Myxoma; Orbit.

Figure 1:

(a and b) Coronal and axial views of non-contrast computed tomography sinus revealing a 2.4 × 2.7 × 2.2 cm expansile lesion involving the bony superior and lateral orbit. There are cortical thinning and loss of portions of the cortical margin, expansion into the left anterior cranial fossa table, and a central matrix with chondroid density, (c and d) T2 coronal and axial magnetic resonance imaging demonstrating the T2 hyperintense and T1 hypointense lesion involving the greater wing of the sphenoid, lateral orbital wall, and orbital roof. Faint dural enhancement of the left anterior cranial fossa overlying the mass was also noted.

Figure 2:

H and E stained sections of the biopsied lesion. (a) Histopathologic analysis of biopsy specimens revealed a hypocellular tumor composed of spindle, stellate, and polyhedral cells within a myxoid stroma, (b) Low-power image reveals reactive woven bone within the myxoma. Immunohistochemistry was positive for vimentin and CD68 and negative for BER-EP4, SMA, S100, MSA, CAM-5.2, PAN-CK, CD34, CD138, and CD1A. These findings were consistent with intraosseous myxoma.

Figure 3:

(a) Axial and (b) coronal cuts of postoperative computed tomography head without contrast following resection of the left superior orbital rim and lateral orbital wall bony mass lesion show no residual bony lesion. Expected small area of the left frontal and soft-tissue extra-axial gas is also noted on sagittal view.