Liposarcoma of the Oral and Salivary Gland Region: A Clinicopathologic Study of 18 Cases with Emphasis on Specific Sites, Morphologic Subtypes, and Clinical Outcome

摘要

Liposarcoma is rare in the oral and salivary gland region (OSG), previously described in only case reports and two small series. Clinicopathologic features of a large series of these tumors were studied. Cases coded as "liposarcoma or lipoma" from 1970 to 2000 were searched for in our files. Inclusion required an OSG location and diagnosis by established soft tissue criteria. Dermal, other soft tissue, and intraosseous liposarcomas were excluded. Clinical and pathologic material was reviewed and follow-up obtained. Eighteen liposarcomas were included: 10 from males and 8 from females. The median patient age was 51 years (range, 30–70 years). Specific anatomic locations included buccal mucosa (n = 7), tongue (n = 4), parotid gland (n = 3), soft tissue overlying the mandible (n = 2), and one each of palate and submandibular gland. The average tumor size was 4.2 cm (range, 1.5 to 6.0 cm). Histologically, most tumors were well differentiated, including one atypical lipoma (n = 10), followed by myxoid (n = 5) and dedifferentiated (n = 3). OSG liposarcomas of all subtypes had increased numbers of lipoblasts. All patients were treated with surgical excision alone. Follow-up on 15 patients (83%) over a mean of 16.5 years (range, 2 to 53 years) revealed that three patients had between one and six local recurrences over periods of 18 months to 6 years. Twelve patients were without recurrence, with a mean follow-up of 12.8 years (range, 2–23 years). No patients, including those with dedifferentiated liposarcoma, had metastases or died of disease. OSG liposarcomas are rare tumors of adults, occurring most commonly in the buccal mucosa, tongue, and then parotid gland. There were no pleomorphic liposarcomas in this series; well-differentiated liposarcoma was the most common subtype, which can locally recur but, even with high-grade dedifferentiation, does not necessarily predict poor outcome. Therefore, OSG liposarcomas have better prognosis than liposarcoma in other soft-tissue locations, perhaps based on smaller size at presentation. Complete local excision and careful patient follow-up, without adjuvant therapy, appears to be the best treatment for OSG liposarcoma.