Orbital alveolar soft part sarcoma: A report of 8 cases and review of the literature.

Alveolar soft part sarcoma (ASPS) is a rare soft tissue neoplasm. The incidence of orbital involvement is the highest in ASPS arising in the head and neck region. However, limited information is available regarding its clinical characteristics. The present study presents the clinical manifestations, imaging findings, pathological features, treatment strategies and prognosis records of 8 cases of orbital ASPS over the last 15 years in a single hospital, along with a review of the literature. Included were 3 male and 5 female patients, with the median age at presentation being 9.5 years. The mean average largest tumour diameter was 3.6 cm. A total of 5 patients underwent surgical excision of the tumour, with 2 undergoing orbital exenteration and 1 undergoing partial orbital exenteration. In total, 6 patients received postoperative radiotherapy and 2 received chemotherapy. Upon follow-up, 6 patients were doing well with no evidence of recurrence or metastasis. Local recurrence developed in 2 patients, of whom 1 succumbed following withdrawal from treatment. According to the present series and the cases mentioned in the literature, orbital alveolar soft part sarcoma has characteristics distinct from those of alveolar soft part sarcoma which arises in other locations. Orbital alveolar soft part sarcoma presents itself in a younger population with a shorter course of disease, smaller tumour size, improved prognosis, a marked association with the extraocular muscles and with the Ki-67 proliferation index possibly associated with prognosis of the disease.