Myxomas and angiomyxomas of the orbit: a clinicopathologic study of 6 cases.

Purpose: To report clinical and histopathologic features and biologic behavior of orbital myxomas and angiomyxomas.

Design: Noncomparative retrospective case series.

Participants: Patients with histopathologic diagnoses of orbital myxoma or angiomyxoma.

Methods: Clinical metadata and features were obtained from the medical record. Neoplasms were studied by routine histopathology, special stains, and immunohistochemistry.

Main Outcome Measures: Final diagnosis, based on histopathology, special stains, and immunohistochemistry, and clinical course from analysis of metadata and clinical features.

Results: Three myxomas and 3 angiomyxomas were identified in 5 males and 1 female. Median age at presentation was 56 years (range, 4-69), with a follow-up ranging from 6 months to 8 years. Two angiomyxomas occurred in children ages 4 and 7 years whose tumors were locally aggressive and recurred. Recurrence also complicated one case of myxoma after incomplete excision. Pathologically, the tumors were poorly circumscribed. Histopathology showed them to be hypocellular, containing stellate and spindled cells in an abundant, loose, myxoid stroma rich in hyaluronic acid. Small blood vessels were rare in myxomas but abundant in angiomyxomas. Tumor cells were frequently immunoreactive for vimentin, CD34, and factor XIIIa.

Conclusions: Myxomas rarely involve orbital tissue, and no angiomyxomas of the region have been previously reported. Angiomyxomas in children may be aggressive. Vascularity and bone involvement appear to be important prognostic features for recurrence. Complete resection with a margin of healthy tissue appears to be the treatment of choice. Tumor cell immunopositivity for vimentin, CD34, and factor XIIIa may assist in the histopathologic diagnosis.