Intraoral liposarcomas are extremely rare. Gagari et al. [
6] reviewed the literature and found that till 2000, only 45 cases had been reported in the literature. A search of the literature revealed that further four cases were reported as single case reports, thus making a total of 49 cases [
7-
9]. Among the various sub-sites in the oral cavity, cheek is the most frequently reported site of involvement followed by oral tongue, floor of mouth, soft palate, mandible, gingiva, upper lip, etc. in decreasing order of frequency (Table
1). The first case of liposarcoma of the floor of mouth was described by Enterline et al [
10] in 1960, and until now, only five cases have been reported in the literature [
9-
13]. The present patient is only 6
th case of liposarcoma of the floor of the mouth in the literature and the first being reported from India. Liposarcoma arises from fatty tissues. The relative lack of these tissues in the head and neck reflects the rarity of finding liposarcoma in these areas, while accounting for their relative abundance in the lower extremities and retroperitoneum. It should be noted that there is relative abundance of adipose tissue in those sites of the head & neck region (i.e., neck, orbit, and cheek, etc.) where majority of the head & neck liposarcomas have been reported.
Enzinger and Winslow [14] proposed the first classification of liposarcoma, currently used by the World Health Organization, grouping histologically into four types, e.g. myxoid, well differentiated, round cell, and pleomorphic. The well differentiated liposarcoma can be divided into several subtypes, including lipoma like, inflammatory, sclerosing and de-differentiated type. Myxoid liposarcoma is the most common type and accounts for approximately 40-50% of all liposarcomas [14,15]. Majority of the head and neck liposarcomas are myxoid type. Of the five previously reported cases of liposarcoma of floor of mouth, majority of the patients had this histologic sub-type. Our patient also had myxoid histology. Liposarcoma has no predilection for any particular race or geographic region. It is most often seen in middle aged patients with slightly higher incidence in men. Yueh et al. [3] reviewed the literature on reported cases of head and neck liposarcoma and observed a significant male predominance (67%), and seen in all age groups from infancy to 88 years, but most commonly found in 5th and 6th decades. Our patient was 35-year-old woman. Surprisingly, most of the liposarcomas involving the floor of the mouth region have been reported in women. Surgery remains the mainstay of the treatment. Many liposarcomas appear to be well circumscribed or encapsulated. However, they actually spread relentlessly into adjacent tissues and their satellite nodules may be missed and left behind at the time of excision. Despite aggressive surgery, 50 to 70% recur locally [15,16]. Enzinger and Winslow [14] reported recurrence rates of 53% for well differentiated and myxoid liposarcoma, while 73% for pleomorphic and 85% for round cell type. Lymph node metastasis is rare, thus, lymphadenectomy is not indicated unless there is evidence of involvement of lymph nodes [17]. Metastases are more commonly hematogenous [10]. Several studies have shown that adjuvant radiotherapy reduces local recurrence after surgery [10,18,19]. Adjuvant chemotherapy has not been proved to be of value [17]. It is reported that highest 5 year survival rate was found in patients with well differentiated and myxoid varieties and the lowest in those with round cell type of liposarcoma [7,16]. In conclusion, liposarcoma of the floor of mouth is an exceptionally rare malignant lesion with poor prognosis. However, in order to reduce the risk of local recurrence, adjuvant post-operative radiotherapy should be considered in initial management of these tumors.
Table 1: Intra-oral cases of liposarcoma classified according to location
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