Conglomerated Facial Liposarcoma

Abstract

Dear Editor: Liposarcoma is the most common soft-tissue tumor occurring in adults1. Most liposarcomas develop in the deep soft tissues of the extremities and retroperitoneum. Only a very small percentage occurs in the head and neck regions2. Although very large liposarcomas are not infrequently found in the intraabdominal regions or extremities, the head and neck liposarcomas mostly occur as small solitary mass which can usually be treated by surgical excision. We report a case of large conglomerated liposarcoma developed on the forehead. A 74-year old woman presented with firmly palpable nodules on the forehead which had existed for 2 years (Fig. 1). Histopathologic evaluation revealed multivacuolated lipoblasts with nuclear pleomorphism and hyperchromatism scattered in the subcutaneous fat (Fig. 2A, B), which was consistent with the well-differentiated liposarcoma. Immunohistochemical stain with S-100 protein was positive in the adipocytes and some lipoblasts (Fig. 2C), while Ki-67 was negative. The magnetic resonance imaging (MRI) showed a large liposarcoma involving the entire forehead and soft tissues to the level of ethmoid sinuses. Neither positron emission tomography-computed tomography nor the neck computed tomography showed nodal involvement or distant metastasis. Initially, she was referred to the plastic surgery for surgical excision, but due to the large extent of the lesion, surgical removal was considered impossible. Instead, concurrent chemo-radiotherapy with doxorubicin (10 mg/m2 weekly) was attempted as the primary treatment. Radiotherapy followed in the standard protocol with fractioned doses of 200 cGy, 5 days a week for 2 months. The facial MRI, 4 months after the initial visit, showed a decreased thickness of the tumor without metastatic lymph nodes. Fig. 1 Multiple firmly palpable subcutaneous nodules on the forehead. Fig. 2 (A, B) Histopathologic evaluation revealed multivacuolated lipoblasts with nuclear pleomorphism and hyperchromatism scattered in the subcutaneous fat (HE A: ×20, B: ×200). (C) S-100 protein was positive in the adipocytes and ... Four histological variants, namely the well-differentiated, myxoid, round cell and pleomorphic liposarcomas, have been described3. The term well-differentiated liposarcoma, the most common subtype, has been designated to describe the nonmetastasizing, low-grade lipomatous tumors with a tendency for local recurrence. Histologically, it resembles the normal fat with scattered multivacuolated lipoblasts, featuring some nuclear pleomorphism and hyperchromatism. Although most authors agree that sarcoma label is appropriate when these lesions are found in retroperitoneum, when they are located in the extremities or elsewhere, some experts prefer the term atypical lipomatous tumor due to the favorable outcome after surgery and the nearly negligible effect on survival4. Complete excision is the treatment of choice for all histologic subtypes. Patients with smaller, well-differentiated or myxoid liposarcomas without local extension may be observed after surgery. Neoadjuvant chemotherapy may be considered in patients with high-grade tumors and for those involving complex anatomical structures, and the use of the adjuvant postoperative chemotherapy would theoretically offer benefits to patients with aggressive tumors. Postoperative radiotherapy may be indicated for patients with high-grade tumors, positive margins, large tumors, local extension and complex anatomic subsites5. The present case is unique in its wide-spread, conglomerated nature and superficial location, which rendered surgical resection impossible. The reports regarding the treatment of facial liposarcomas without surgery are very limited in the literature. The well-differentiated liposarcomas show nearly 100% 5 year survival rate without metastasis, despite frequent local recurrence after surgery. In addition, scalp or face tumors are known to have a better prognosis than the oral tumors1. Long-term follow-up would be required to determine the treatment outcome.