Primary oral and maxillofacial liposarcoma: a ... … · Key words: liposarcoma, oral maxillofacial region, surgery, prognosis. Introduction Liposarcoma represents one of the most

Primary oral and maxillofacial liposarcoma:a clinicopathological and immunohistochemical studyof eleven cases

Jie Cheng1,2, Hongbo Yu1, Lizhen Wang3, Xudong Wang1, Guofang Shen1

A b s t r a c t

Introduction: The present study was aimed to characterize the clinicopatholog-ical, immunohistochemical features and treatment outcomes of primary oraland maxillofacial liposarcomas by presenting the experience over a 16-year peri-od at a tertiary referral Chinese institution for head neck cancer.Material and methods: This retrospective clinical study included 11 cases ofpathologically confirmed primary liposarcomas treated from January 1993 toSeptember 2009. Detailed information regarding primary site, clinical manifes-tations, histopathological and immunohistochemical analysis, treatments andprognosis was collected and reported.Results: Eight female and 3 male patients aged from 8 to 76 years old. Theselesions occurred in buccal (3), parotid (2), temporal (2), tongue (2), palate (1)and oropharyngeal (1) region. They were histopathologically categorized into 4 subtypes based on WHO classification scheme: atypical lipomatous tumor/well-differentiated (4), myxoid (4), mixed-type (2) and pleomorphic (1) liposarcomas.Immunohistochemical staining indicated mostly positive for Vimentin and S-100 but negative for other markers. Most patients presented as slow-grow-ing painless masses and underwent surgery alone or combined with postoper-ative radiotherapy. Two patients were misdiagnosed and inappropriate treatedand developed local relapse before referred to our institute. No distant metas-tasis and one disease-related death were recorded during the follow-up (ranging:1-11 years, mean: 4.5 years).Conclusions: Oral and maxillofacial liposarcoma is exceedingly rare and hasatypical clinical manifestations but characteristic histopathology. Complete exci-sion with negative margins followed by long-term follow-up is recommendedas the treatment of choice for these uncommon entities.

Key words: liposarcoma, oral maxillofacial region, surgery, prognosis.

Introduction

Liposarcoma represents one of the most common mesenchymal malig-nant neoplasms, approximately accounting for 20% of all soft tissue sar-comas [1]. It predominantly occurs in the extremities and retroperitoneumand is extremely rare in the oral and maxillofacial region. To our knowl-

Corresponding author:Guofang Shen MD, DDS639 Zhizaoju RoadShanghai 200011, PR ChinaPhone/fax: +86-021-23271699E-mail: [email protected]

Clinical research

1Department of Oral and Maxillofacial Surgery, Shanghai Ninth People’s Hospital, Shanghai Jiao Tong University, School of Medicine, Shanghai, China

2Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital, Nanjing Medical University, Jiangsu, China

3Department of Oral Pathology, Shanghai Ninth People’s Hospital, Shanghai Jiao TongUniversity, School of Medicine, Shanghai, China

Submitted: 10 November 2010Acccepted: 22 January 2011

Arch Med Sci 2012; 8, 2: 316-323DOI: 10.5114/aoms.2012.28560Copyright © 2012 Termedia & Banach

Arch Med Sci 2, April / 2012 317

edge, only limited case reports and small series ofprimary liposarcomas involved in this anatomicregion have been previously published [2-7]. Thecomprehensive clinicopathological information aswell as treatment modalities and outcomes of thisuncommon malignancy were poorly described thusfar. Moreover, the rarity of liposarcoma togetherwith its frequently atypical clinical presentationsmay probably lead to misdiagnosis and inappropri-ate management with compromised prognosis.Therefore, a more thorough understanding of theepidemiology, histopathological characteristics oforal and maxillofacial liposarcoma is urgentlyrequired to optimize the diagnosis and treatmentstrategies to achieve better outcomes.

Liposarcomas within oral and maxillofacial regionusually present as slow-growing painless mass inindividuals with a peak incidence between 40 and60 years of age [8]. A male preponderance and buc-cal mucosa as the site of predilection for them werereported [3, 9]. Advances in genetic and molecularinvestigation have revealed that liposarcoma isa heterogeneous group of tumors composed of fivehistological subtypes with distinct morphology,cytogenetic abnormalities and clinical features asshown in the latest WHO classification for soft tis-sue sarcoma [10]. The precise diagnosis of liposar-coma relies heavily on the histopathological exam-ination before or after surgery. Complete surgicalexcision remains the mainstream treatment modal-ity for liposarcomas [11]. However, no consensusabout the optimized treatment options and properprognosis prediction for these malignancies existsuntil now.

In the present study, the clinicopathological andimmunohistochemical data, clinical presentation,treatments and disease-specific outcomes regard-ing primary oral and maxillofacial liposarcomastreated in a tertiary referral Chinese hospital werereported in detail.

Material and methods

The oral and maxillofacial tumor registry ofShanghai Ninth people’s hospital affiliated toShanghai Jiao Tong University was searched andrelevant medical records were reviewed to retrieveinformation for patients diagnosed as primary oraland maxillofacial liposarcomas between January1993 and September 2009. Inclusion criteria com-prised an oral and maxillofacial location for primarylesion and definitive diagnosis by establishedpathological criteria for liposarcoma. The archivedH&E and immunohistochemical slides availablewere further retrieved and reviewed independent-ly by the senior oral pathologists. The research pro-tocol was approved by the Institutional ReviewCommittee of Shanghai Jiao Tong University Med-ical School. Informed consents were obtained from

patients or patient relatives. The clinical and fol-low-up information of these patients includingdemographics, primary tumor site, histological sub-types, treatment modality and outcomes from med-ical records were collected and presented.

During surgery, these lesions were excised about1.5 cm away from the tumor margin. After surgicalremoval of the lesions, the tissue specimen wereimmediately transferred to oral pathology unit andsubjected to pathological examination by frozensections. The three-dimensional margins were alsodetermined by frozen sections to avoid possibleresidual tumor. After surgery, the surgical sampleswere fixed in 10% buffered formalin and sectionedin 4-μm slides for hematoxylin-eosin staining andimmunohistochemical staining using standard pro-cedures. The commercial available antibodies toVimentin, S-100, CD34, CD99, smooth-muscle actin(SMA), CKpan, Desmin, muscle-specific actin (MSA)were used together with DAB staining system withappropriate positive and negative controls.Immunoreactivity for each protein was determinedbased on the proportion of stained cells and expect-ed subcellular locations. Negative control was pre-pared using phosphate buffer solution (PBS) insteadof primary and second antibodies.

Most patients in this series underwent completelocal excision with disease-free margins. To reducethe possibility of local recurrence, postoperativeradiotherapy (about 55-60 Gy) was administered toselected cases. Two recurrent patients who weremisdiagnosed and inappropriate treated in localhospital were received another surgical resectionin our institute followed by chemotherapy. Largelesions which were more than 5 cm in largestdimension in other two patients and they were rec-ommended for radiotherapy after surgery. Nochemotherapy before and after surgery were givendue to the insensitiveness of liposarcoma to chem-ical agents. All patients were recommended to par-ticipate in long-term follow-up at regular intervals.

Results

Demographic and clinical features

Through tumor registry search and furtherpathological confirmation of initial diagnosis, elevencases of primary oral and maxillofacial liposarco-mas were enrolled and briefly showed in Table I.Eight patients were females and the others weremales, indicating a female predominance (8 : 3).The mean age of patients were 33.7 years. Thelesions were found in buccal mucosa (3), temporal(2), parotid (2), ventral tongue (2), palate (1) andthe lateral pharyngeal wall (1). Clinical manifesta-tions of this malignancy varied largely dependingon the areas involved. Most lesions typically beganas slowly-growing and painless masses with dif-

Primary oral and maxillofacial liposarcoma: a clinicopathological and immunohistochemical study of eleven cases

318 Arch Med Sci 2, April / 2012

ferent intervals between tumor onset and clinicalpresentation. The main reasons for patients to seektreatment were accelerated growth of masses andresulting facial disfigurement and the developmentof pain. Liposarcoma in the parotid region oftenresembled a begin tumor without obvious facialnerve paralysis. However, when large parotid lesionsextended toward parapharygeal space or para-pharygeal liposarcoma developed, diverse severitiesof airway obstruction, dysphagia and night snoringoccurred (Figure 1). Computed tomography (CT) andMagnetic resonance imaging (MRI) were usuallyemployed to determine the precise location andboundary as well as its relationship with adjacenttissues. Images of ALT/WD liposarcoma usuallyshowed similar signal intensity equal to fat thatclosely resemble lipoma and characteristic thickenedsepta (Figure 1). Other subtypes of liposarcomasshowed no remarkable difference to other soft-tis-sue malignancies in CT/MRI images. Among thesepatients, wide local excision with negative marginswas the most common treatment modality. Radicalresection was carried out for patients with localrecurrence. Postoperative radiotherapy was alsoadministered to four patients, mainly due to largelesions and recurrent cases. Follow-up period rangedfrom 1 to 11 years (mean: 4.5 years). Ten patientsremained alive until last follow-up, while only 1 patient died of recurrent lesions adjacent to brainand cranial base. Two patients had recurrent lesionsabout 2-3 months after initial incomplete excisionin local hospital before admitted to our department.No evidence of distant metastasis was recorded.

Histopathological and immunohistochemicalfindings

Macroscopically, liposarcomas often appearedas soft-tissue mass containing diverse extent of

hemorrhage and necrosis and varied from well-cir-cumscribed, multilubolated and partially encapsu-lated to less well-delineated and more invasive andinfiltrating with adjacent tissue. The colors of tumorcut surfaces ranged from yellow to grey and fromgreasy to mucoid and gelatinous mainly dependingon different histopathologic types. Based onhistopathology and the latest WHO classificationfor liposarcoma, eight cases were categorized asatypical lipomatous tumor/well differentiated(ALT/WD) and myxoid liposarcoma. Two cases weresubtyped as mixted-type and 1 patient had pleo-morphic liposarcoma.

Under microscopy, ALT/WD subtype was char-acterized by the presence of mature adipocyteswith significant variation in cell size and scatterednuclear atypia and variable number of atypicalstromal cells (Figure 2). The atypical stromal cellswere spindle and often identified with hyper-chromatic nuclei embedded within mature adiposetissue. Rare scattered and monovacuolated or mul-tivacuolated lipoblasts could be found. The casewith multiple recurrences was diagnosed as lipo-ma-like subtype of ALT/WD liposarcoma. No evi-dence of dedifferentiation of ALT/WD or othertypes of malignancy could be detected in therelapsed lesions. Myxoid liposarcoma consistedround primitive nonlipogenic mesenchymal cellsand a few small signet-ring lipoblasts within promi-nent myxoid stroma (Figure 3). Rich and delicatebranching capillary architecture was frequentlyobserved and sometimes vessel and perineuralinvasions could be detected. As to pleomorphicliposarcoma, it comprised of pleomorphic lipo -blasts in the background of plemorphic sarcoma.The plemorphic round and spindled tumor cellswere mixed with multinucleated giant cells which were morphologically similar to malignant

Case no. Age [years] Gender Primary sites Pathologic subtype Treatment Treatment outcome

1 21 Female Right parotid region Myxoid SE + PR NED

2 26 Female Right pharyngeal region ALT/WD SE NED

3 25 Female Left buccal region ALT/WD SE + PR R, D

4 11 Female Left buccal region Pleomorphic SE NED

5 8 Female Left ventral tongue Myxoid SE NED

6 46 Male Left palate Mixed-type SE NED

7 43 Female Left temporal region Myxoid SE NED

8 28 Female Left buccal region Mixed-type SE + PR NED

9 48 Female Right temporal region Myxoid SE + PR NED

10 39 Male Right parotid region ALT/WD SE NED

11 76 Male Left ventral tongue ALT/WD SE NED

ALT/WD – atypical lipmatous tumor/well differentiated liposarcoma, SE – surgical excision, SE + PR – surgical excision + postoperative radio-therapy, NED – no evidence of disease, R – recurrence, D – death

Table I. Clinicopathological characteristics and treatment outcome of 11 oral and maxillofacial liposarcomas

Jie Cheng, Hongbo Yu, Lizhen Wang, Xudong Wang, Guofang Shen



fibrous histocytoma (Figure 4). High mitotic activ-ity and intramuscular invasion of tumor could beobserved. Mixed-type liposarcoma showed thediverse morphological features of myxoid liposar-coma and ALT/WD or pleomorphic liposarcoma inthe lesions with clear boundary. Among the mixed-type lesions, different parts had their own char-acteristic cell morphology and histopathologicalfeatures (Figure 5).

Immunohistochemical staining results availablefor 7 cases showed that vimentin and S-100 werepositive most cases. However, CD99, α-SMA, MSA,CKp and Des commonly appeared negative (Table II).Despite limited values for direct diagnosis for liposar-coma based on immunohistochemical staining, theseresults were valuable for differential diagnosis amongdiverse types of malignancies.

Discussion

Liposarcoma, first described by Virchow in 1857,is considered as one of the most common soft tis-sue sarcomas in adults. However, it rarely involvesthe oral and maxillofacial region [9, 12]. Its rarityand lack of characteristic symptoms and signsreduced the opportunity to early detect and man-agement [13]. The lack of adequate informationregarding the clinicopathological features and prog-nostic factors for this rare tumor further makes ear-ly diagnosis and treatment planning difficult. Ourdata reported here may improve our understand-ing of clinicopathological features of oral and max-illofacial liposarcoma to avoid misdiagnosis and mis-treatment in the clinic.

Previous reports showed a male/female ratio ofabout 2 : 1 for liposarcoma in the head and neck

Figure 1. ALT/WD liposarcoma in the right parotid region. A-B – Frontal and lateral view of a male patient with parotidliposarcoma. C-D – MRI images showed a well-defined mass with irregular margins in the right parotid region andextending toward parapharyngeal space (C – axial fat-suppressed T2 weighted, D – T2 weighted)

A B

C D


region, indicating a male preponderance for thistumor [2, 11]. However, an obvious female pre-dominance (female/male: 8 : 3) was found in ourseries. Similarly, Zheng et al. reported female pre-ponderance with the female/male ratio of 4 : 1 intheir series of Chinese origin [5]. The discrepancyof gender distribution may be due to limited num-ber of cases analyzed and/or genetic in origin.Moreover, the average age (33.7 years) in the Chi-nese cohort is also lower than that in previous stud-ies, as previous reports indicated the age of pres-entation ranging from 30 and 60 years with a peakin the sixth decades [14]. Notably, two female pae-diatric patients with 8 and 11 years old were includ-ed, being myxoid and pleomorphic subtype arisingfrom buccal mucosa and ventral tongue, respec-tively. Pediatric liposarcoma is extremely unusualand significantly different from adult cases. Alag-gio et al. reported that conventional myxoid liposar-coma was the most common subtype with excel-lent prognosis in patients younger than 22 year ofage [15]. These two paediatric patients underwentwide local excision with negative margins and hadno local recurrence and metastasis during the fol-low-up. This finding reminds the clinicians that oraland maxillofacial liposarcoma can even occur in chil-dren and adolescent.

As the sites of predilection for oral liposarcomas,the buccal mucosa is the most common site in thisseries which is consistent with previous studies [16].Of note, two parotid liposarcomas were found andboth were pathologically classified as ALT/WD. Nosuch lesions were found in minor salivary glands.One patient was initially misdiagnosed as pleo-morphic adenoma and inappropriately treated inlocal hospitals, then developed recurrent lesion 2 month later. To our knowledge, although ten cas-es of liposarcomas in the parotid region were report-ed in the English literature so far, only one casewith definitive diagnosis of parotid ALT/WD waspreviously documented by Fanburg-Smith et al. withunspecified treatment and no recurrence during 2 years follow-up [9]. Therefore, our two casesmight add some important information to betterunderstanding of parotid ALT/WD and remind sur-geons to be alert about the diagnosis and treatmentof such rare tumor in the parotid region.

The liposarcomas within oral and maxillofacialregion often appear as painless, slow-growingswelling or soft-tissue masses. On the first exami-nation, these disease entities tend to be perceivedas benign tumors. Three patients in this series hadinitial misdiagnosis and incomplete excision and 2 patients developed local recurrence before

Figure 2. Histopathological and immunohistochemical examination of ALT/WD liposarcoma. Mature adipocytes withdiverse size, multi-vacuolated lipoblasts and variable number of atypical stromal cells as showed by H + E staining(A). Immunohistochemical staining for vimentin (B), S-100 (C), CD99 (D). Magnification 200×

D

A B

C



Figure 3. Histopathological and immunohistochemical examination of myxoid liposarcoma. Multivacuolated andsignet-ring primitive cells within the prominent myxoid stroma as showed by H&E staining (A). Magnification 100×.Immunohistochemical staining for, S-100 (B), vimentin (C) CD34 (D). Magnification 400×

D

A B

C

A B C

Figure 4. Histopathological examination of pleomorphic liposarcoma. The tumor consists of pleomorphic sarcoma(left area) and pleomorphic lipoblasts (right area) as showed by H&E staining. Magnification 100× (A). The pleo-morphic sarcoma is similar to malignant fibrous histocytoma and contains round and pleomorphic tumor cells withmitosis. Magnification 400× (B). The lipoblasts shown nuclear atypia. Magnification 400× (C)

A B C

Figure 5. Histopathological examination of mixed-type (ALT/WD & myxoid) liposarcoma. The lesion consists ofALT/WD (upper area) and myxoid liposarcoma (lower area) with apparent boundary as showed by H&E staining.Magnification 100× (A). The ALT/WD (B) and myxoid part (C) each shows characteristic histology. Magnification 400×



referred to our department. Therefore, differentialdiagnosis of such masses is essential and shouldinclude various benign and malignant lesions suchas lipomas, lymphadenopathies, branchial cyst andHodgkin lymphoma, et al. The presence of fat in CTand MRI images may suggest a lipomatous tumorsuch as lipoma and liposarcoma. Several charac-teristic findings including more than 75% fat, thicksepta may contribute a lot to differential diagnosisbetween lipoma and ALT/WD [17, 18]. However, it’sfairly difficult to definitely diagnose such massesbetween liposarcomas and other soft tissue neo-plasm based on radiography.

Histological examination of liposarcoma is piv-otal for diagnosis establishment. Tumor cells withcharacteristic morphology contribute to diagnosisand subtype classifications. The most common his-tologic subtypes in our series, in agreement withprevious findings, are ALT/WD and myxoid liposar-coma. The lipogenic differentiation marker S-100,indicative of the presence of lipoblasts, was stainedpositive in ALT/WD and myxoid liposarcoma, butnegative in other subtypes. Although no specificmolecular markers exist for its diagnosis, howev-er, such markers by immunohistochemistry maybe beneficial for differential diagnosis and subtypeclassification. The cytogenetic feature of ALT/WDand dedifferentiated liposarcoma has beenrevealed in the form of supernumerary ring or giantmarker chromosomes with 12q13-15 amplification[19]. Several tumor-associated genes includingMDM2, HMGA2 and CDK4 were identified andproven beneficial for differential diagnosis byimmunohistochemical detection or fluorescent insitu hybridization [20]. Moreover, fine needle aspi-ration biopsy was suggested as a valuable andpromising technique for preoperative diagnosisespecially in the deep region [21]. Therefore, fur-ther studies were warranted to determine the rolesof such tumor biomarkers in early detection, patho-logical categorization and prognostic prediction forliposarcoma [22].

Complete surgical excision with free margins isthe primary treatment option for liposarcomas [2,

9, 13]. The values of adjuvant radiotherapy andchemotherapy for liposarcoma still remain contro-versial. Radiotherapy alone is occasionally consid-ered as an alternative for selected cases especial-ly for impossible total excision or recurrent tumors.Careful follow-up after complete excision has beenrecommended for monitoring recurrence and dis-tant metastasis. Local recurrence, usually resultingfrom incomplete excision becomes a common chal-lenge for successful management of liposarcoma.Although these tumors sometimes appear wellencapsulated, wide excision should be emphasizedto avoid nay microscopic residual disease. In ourcases, excisions were performed at least 1.5 cmfrom the palpable margins of lesions to guaranteecomplete removal when possible. However, theproximity of vital neurovascular structures andensuing severe morbidities caused by wide excisionsometimes limited the extent of excision. There-fore, adjuvant postoperative radiotherapy is some-times needed for selected cases especially whencomplete excision was unattainable. It has beensuggested that radiotherapy delayed tumor growthand prevented local recurrence [23]. Golledge et al.reported that patients treated with surgery alonehad a 5-year survival rate of 83% as compared with63% for those treated with combined surgery andradiotherapy [2]. Four patients reported here under-went surgery combined postoperative radiothera-py and had satisfactory results without evidence ofrecurrence. Based on our experience and previousreports, adjuvant radiotherapy should be consid-ered as a valuable treatment alternative for localdisease control after incomplete excision or suspi-cious disease left. In addition, no study has offeredconclusive evidence supporting the treatment util-ity of chemotherapy for liposarcoma.

Although previous studies suggested that tumorsize, histological subtype and treatment correlatedwith biological behaviors and prognosis of liposar-comas, we didn’t confidentially draw conclusionsabout the relationship between prognosis and theseclinicopathological variables largely due to limitednumber of cases. But, in general, oral and maxillo-

Case Vim S-100 CD34 CD99 α-SMA CKp EMA Des

1 + + + – – – – –

4 + – – – – – – –

6 + ± – – – – – –

8 + ± + – – – – –

9 + – – – – – – –

10 + + – + – – – –

11 + + – ± – – – ±

Vim – vimentin, α-SMA – α-smooth muscle actin, MSA – muscle-specific actin, CKp – pan-cytokeratin, EMA – epithelial membrane antigen, Des – desmin, positive: +, negative: –, partial positive: ±

Table II. Immunohistochemical analyses of oral and maxillofacial liposarcomas



facial liposarcomas had good prognosis as sup-ported by our data and others findings, presumablyowing to easy detection and timely therapeuticintervention.

In conclusion, we retrospectively reviewed 11 cas-es of primary liposarcomas within oral and max-illofacial region and described the clinicopatholog-ical features and treatment outcomes in detail. Ourstudy indicated that these rare tumors developedfrom various anatomic sites, most frequently in thebuccal mucosa and usually identified as ALT/WDand myxoid subtypes by histopathology. The treat-ment outcomes of these patients receiving surgeryor together with radiotherapy were favorable with90.9% disease-free survival during the follow-up,rare recurrence and no metastasis. It’s criticallyessential for clinicians to keep the possible diag-nosis of liposarcoma in mind when diagnosingmasses in the oral and maxillofacial region. Moreretrospective and perspective studies are still need-ed to establish the optimized diagnosis and treat-ment regimes for oral and maxillofacial liposarco-ma.

Acknowledgments

These works were financially supported byresearch Grant 2007BAI 118B04 from National Key Technology R&D Pillar Program in the 11th

5 year plan of China, National Natural Science Foundation of China (Grant No. 81100737) and Natural Science Foundation of Jiangsu Province (GrantNo. BK2011762).

Re f e r e n c e s1. Mack TM. Sarcomas and other malignancies of soft tissue,

retroperitoneum, peritoneum, pleura, heart, mediastinum,and spleen. Cancer 1995; 75: 211-44.

2. Golledge J, Fisher C, Rhys-Evans PH. Head and neckliposarcoma. Cancer 1995; 76: 1051-8.

3. Nascimento AF, McMenamin ME, Fletcher CD. Lipo -sarcomas/atypical lipomatous tumors of the oral cavity:a clinicopathologic study of 23 cases. Ann Diagn Pathol2002; 6: 83-93.

4. Titiz A, Yilmaz YF, Ceyhan S, Unal T. Atypical lipomatoustumor in the submental region. J Craniofac Surg 2008;19: 1558-60.

5. Zheng JW, Wang Y. Liposarcoma in the oral and maxil -lofacial region: an analysis of 10 consecutive patients. J Oral Maxillofac Surg 1994; 52: 595-8.

6. DeWitt J, Heidelman J, Summerlin DJ, Tomich C. Atypicallipomatous tumors of the oral cavity: a report of 2 cases.J Oral Maxillofac Surg 2008; 66: 366-9.

7. Chandan VS, Fung EK, Woods CI, de la Roza G. Primarypleomorphic liposarcoma of the parotid gland: a casereport and review of the literature. Am J Otolaryngol 2004;25: 432-7.

8. Dei Tos AP. Liposarcoma: new entities and evolvingconcepts. Ann Diagn Pathol 2000; 4: 252-66.

9. Fanburg-Smith JC, Furlong MA, Childers EL. Liposarcomaof the oral and salivary gland region: a clinicopathologic

study of 18 cases with emphasis on specific sites,morphologic subtypes, and clinical outcome. Mod Pathol2002; 15: 1020-31.

10. Fletcher CD, Unni KK, Mertens F (eds). Adipocytic tumors.In: World Health Organization classification of tumors:pathology and genetics of tumors of soft tissue and bone.IARC Press, Lyon 2002; 35-46.

11. Davis EC, Ballo MT, Luna MA, et al. Liposarcoma of thehead and neck: The University of Texas M.D. AndersonCancer Center experience. Head Neck 2009; 31: 28-36.

12. Weiss SW, Goldblum JR. Liposarcoma. In: Enzinger’s andWeiss’s soft tissue tumors. Weiss SW, Goldblum JR (eds).Mosby, St. Louis 2001; 641-93.

13. Dalal KM, Antonescu CR, Singer S. Diagnosis andmanagement of lipomatous tumors. J Surg Oncol 2008;97: 298-313.

14. Stewart MG, Schwartz MR, Alford BR. Atypical andmalignant lipomatous lesions of the head and neck. ArchOtolaryngol Head Neck Surg 1994; 120: 1151-5.

15. Alaggio R, Coffin CM, Weiss SW, et al. Liposarcomas inyoung patients: a study of 82 cases occurring in patientsyounger than 22 years of age. Am J Surg Pathol 2009; 33:645-58.

16. Charnock DR, Jett T, Heise G, Taylor R. Liposarcoma arisingin the cheek: report of a case and review of the literature.J Oral Maxillofac Surg 1991; 49: 298-300.

17. Munk PL, Lee MJ, Janzen DL, et al. Lipoma and lipo -sarcoma: evaluation using CT and MR imaging. AJR Am J Roentgenol 1997; 169: 589-94.

18. Hosono M, Kobayashi H, Fujimoto R, et al. Septum-likestructures in lipoma and liposarcoma: MR imaging andpathologic correlation. Skeletal Radiol 1997; 26: 150-4.

19. Micci F, Teixeira MR, Bjerkehagen B, Heim S. Charac -terization of supernumerary rings and giant markerchromosomes in well-differentiated lipomatous tumorsby a combination of G-banding, CGH, M-FISH, andchromosome- and locus-specific FISH. Cytogenet GenomeRes 2002; 97: 13-9.

20. Dei Tos AP, Doglioni C, Piccinin S, et al. Coordinatedexpression and amplification of the MDM2, CDK4, andHMGI-C genes in atypical lipomatous tumours. J Pathol2000; 190: 531-6.

21. Klijanienko J, Caillaud JM, Lagacé R. Fine-needle aspirationin liposarcoma: cytohistologic correlative study includingwell-differentiated, myxoid, and pleomorphic variants.Diagn Cytopathol 2004; 30: 307-12.

22. de Vreeze RS, de Jong D, Nederlof PM, et al. Added valueof molecular biological analysis in diagnosis and clinicalmanagement of liposarcoma: a 30-year single-institutionexperience. Ann Surg Oncol 2010; 17: 686-93.

23. Eeles RA, Fisher C, A'Hern RP, et al. Head and necksarcomas: prognostic factors and implications fortreatment. Br J Cancer 1993; 68: 201-7.


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Primary oral and maxillofacial liposarcoma: a ... … · Key words: liposarcoma, oral maxillofacial region, surgery, prognosis. Introduction Liposarcoma represents one of the most