K. Tanio et al.

ACBDFig. 6. This SFT tumor shows diffuse and strong immunoreactivity for CD34 (A) and bcl-2 (B) but is negative to SMT (C), S100 protein (D) and c-kit (E). Bar =100 µm.

malignant transformation of SFT for patients with along clinical history. Concerning the incidence of
SFT in the oral cavity, the buccal mucosa or cheekshows higher levels, followed by the tongue.
MRI images of SFT for this patient showed asignal intensity homogeneous to that of the muscle
on both T1- and T2-weighted images. Likewise,
Sato et al. (1998) reported that low signal levels
on both T1- and T2-weighted images would becharacteristic of SFT. However, even though some
reports showed low levels on T1-weighted images,
high levels on T2-weighted images were also seen
(Yanamoto et al., 2003). We think that the histological diversity of SFT leads to the difference in
MRI findings.

EGenerally, diagnosing SFT is difficult becauseof its broad range of morphologic characteristics,
including storiform, hemangiopericytic, herringbone and palisading areas (Chan, 1997). In
the present case, we observed a storiform patternalong with a stag-horn appearance occasionallyseen in hemangiopericytoma. Therefore, the current diagnosis of SFT has been based on histologi-78

SFT of the buccal mucosa

1ReportAge Sex(yr)Location

1994 55 M Sublingualgland2 Suster et al.
1995 50 F Soft palate
3 Suster et al.
1995 83 M Cheek
4 Piatteli et al.
1998 66 F Tongue
5 Iwai et al.
1999 27 M Buccal mucosa
6 Kurihara et al.
1999 34 F Buccal mucosa
7 Perez-Ordonez et al. 1999 39 F Mandible
8 Perez-Ordonez et al. 1999 70 M Buccal mucosa
9 Brunnemann et al. 1999 46 F Buccal mucosa
10 Brunnemann et al. 1999 53 M Oral mucosa
11 Lukinmaa et al.
2000 56 M Cheek
12 Lukinmaa et al.
2000 45 F Cheek
13 Lukinmaa et al.
2000 70 M Cheek
14 Hirano et al.
2001 64 F Mental
15 Kuo et al.
2001 31 M Infraorbital
16 Alawi et al.
2001 44 F Tongue
17 Alawi et al.
2001 40 M Buccal mucosa
18 Alawi et al.
2001 55 M Buccal mucosa
19 Alawi et al.
2001 51 F Buccal mucosa
20 Alawi et al.
2001 38 F Buccal mucosa
21 Alawi et al.
2001 31 F Buccal mucosa
22 Alawi et al.
2001 61 M Buccal mucosa
23 Alawi et al.
2001 63 M Buccal mucosa
24 Alawi et al.
2001 60 F Buccal mucosa
25 Alawi et al.
2001 58 F Buccal mucosa
26 Alawi et al.
2001 64 F Lower Lip
27 Alawi et al.
2001 67 F Buccal mucosa
28 Alawi et al.
2001 60 M Buccal mucosa
29 Alawi et al.
2001 73 F Buccal mucosa
30 Alawi et al.
2001 48 F Tongue
31 Alawi et al.
2001 36 M Lower Lip
32 Shin et al.
2001 46 M Buccal mucosa
33 Harada et al.
2002 32 M Gingival
34 Hardisson et al.
2002 56 F Cheek
35 Vargas et al.
2002 20 F Cheek
36 Vargas et al.
2002 65 F Tongue
37* Shnayder et al.
2003 57 F Tongue
38 Yamamoto et al.
2003 32 M Buccal mucosa
39 Tanio et al.
Present 56 M Buccal mucosa

ckit

Number

CD
34
V
iment
bc i nl -2
SM
A
Desmi
S- n
100Cy
toke
F - ratin
8Table 1. Clinical and pathologic features of 39 patients with intraoral SFT

12 yr NA + NA NA–– NA NA
NA++ NA NA–– NA –NA++ NA NA–– NA –1 yr +++NA NA –––5 yr ++ NA NA NA – NA NA
3 yr ++ NA–––––
1 mo +++NA–– NA NA
NA++–NA–– NA NA
NA NA NA NA NA NA NA NA NA
NA NA NA NA NA NA NA NA NA
10 yr +++–
NA –– NA
6 mo +++–NA –– NA
6 mo +++–NA –– NA
9 yr ++ NA+–– NA NA
4 yr +++–
NA –– NA
NA+NA
NA
1 yr +NANA
3 yr +NANA
3 yr +
NA
NANA+NANA
2 yr +NA
NA+,+,+,
2.5 yr +NA
NA13/13†2/13†
0/5†NA+NA
NA+,+,
15 yr +
NANA
12/13†
NA+NA 0/10†NA
11 mo +NA
NA
NA+NA
NA
NA+NA
NA
50 yr +NANA
8 mo +
NANA
4 mo +NANA
1 mo ++ NA NA––– NA
5 yr ++ NA––– NA NA
2 yr +++NA–– NA –
6 mo +++–––– NA
15 yr +++–––– NA
25 yr +++–––– NA
1 yr +++–––––
24 mo + NA +–NA – NA NA

NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA–NA
NA
NA
NA
NA
NA
NANA
NANANANANANANANANANANANANA
NA–NA–

Size Clin(mm) ical
historyGunhan et al.

304015102015104029222015103240
11123340
1430
33
98813121713882710153048
253530* Case 37 was the only malignant tumor in this series.
† Positive case(s)/examined cases reported in Alawi et al. (2001).
F, female; M, male; mo, month(s); NA, not available; SFT, solitary fibrous tumor; SMA, smooth muscle actin; yr,year(s).

79K. Tanio et al.
cal and immunohistochemical findings. In 1997,
Chan proposed an immunohistochemical profile inwhich SFT is immunopositive to vimentin, CD34
and bcl-2, but is negative to cytokeratin, von Willebrand factor, SMA and S-100 protein. In 56
pleural and extrapleural SFTs, Suster et al. (1998)
showed a close correlation between the expressionsof CD34 and bcl-2. The present case and othercases shown in Table 1 were positive to CD34 andbcl-2. Although many reports have emphasized
the importance of CD34 in diagnosis of SFT, CD34
immunopositivity is not specific to SFT. Tumors
including hemangiopericytoma, neurofibroma,neurilemmoma, angioleiomyoma, gastrointestinal
stromal tumor (GIST) and dermatofibrosarcoma
protuberans are positive to CD34. Neurofibroma
and neurilemmoma are usually positive to S-100
protein, whereas SFT is negative. Dermatofibrosarcoma protuberans is rarely involved in oral soft
tissues, but it can be distinguished from SFT by
its malignant cytologic features. Also, angioleiomyoma is positive to SMA, where SFT is usuallynegative. GIST is positive to c-kit. Hemangiopericytoma is probably the most difficult to be distinguished from SFT, because SFT often presents
hemangiopericytoma-like areas. Hemangiopericytoma also has immunoactivity for CD34 like SFT.
However, hemangio-pericytoma lacks the othermorphologic features associated with SFT, such as
the storiform pattern, herringbone pattern, neuralpalisades and thick collagenous stroma. Thesefacts convinced us that we should differentiate thiscase as SFT.
Diagnosis of SFT is difficult and, although uncommon, it should be contained in the differential
diagnosis of oral soft tissue tumors. We reported arare case of SFT and reviewed 38 cases of intraoral
SFT.

Solitary fibrous tumor: a cytologyic-histologic study
with clinical, radiologic and immunohistochemicalcorrelations. Cancer 1997;81:116–121.
3 Brunnemann RB, Ro JY, Ordonez NG, Mooney J,El-Naggar AK, Ayala AG. Extrapleural solitary fibrous tumor: a clinicopathologic study of 24 cases.
Modern Pathol 1999;12:1034–1042.
4 Chan JK. Solitary fibrous tumour: everywhere, anda diagnosis in vogue. Histopathology 1997;31:568–576.
5 Dervan PA, Tobin B, O’connor M. Solitary (localized) fibrous mesothelioma: evidence against mesothelial cell origin. Histopathology 1986;10:867–875.
6 England DM, Hochholzer L, McCarthy MJ. Localized benign and malignant fibrous tumors of thepleura: a clinicopathologic review of 223 cases.
Am J Surg Pathol 1989;13:640–658.
7 Goodlad JR, Fletcher CDM. Solitary fibrous tumour arising at unusual sites: analysis of a series.
Histopathology 1991;19:515–522.
8 Gunhan O, Yildiz FR, Celasun B, Onder T, FinciR. Solitary fibrous tumor arising from sublingualgland: report of a case. J Laryngol Otol 1994;108:998–1000.
9 Harada T, Matsuda H, Maruyama R, Yoshimura
Y. Solitary fibrous tumours of the lower gingival:a case report. Int J Oral Maxillofac Surg 2002;34:448–450.
10 Hardisson D, Cuevas-Santos J, Contreras F. Solitary fibrous tumor of the skin. J Am Acad Dermatol
2002;46:37–40.
11 Hirano M, Tanuma J, Shimoda T, Sugihara K,
Tsuneyoshi M, Kitano M. Solitary fibrous tumor in
the mental region. Pathol Int 2001;51:905–908.
12 Iwai S, Nakazawa M, Yoshikawa F, Amekawa S,Sakuda M. Solitary fibrous tumor of the buccal
mucosa: report of a case with immunohistochemical studies. Oral Surg Oral Med Oral Pathol OralRadiol Endod 1999;88:461–465.
13 Klemperer P, Rabin CB. Primary neoplasmas of thepleura. Arch Pathol 1931;11:385–412.
14 Kuo WP, Sirois DA, Pemble CW. Locally aggressive solitary fibrous tumor in the infraorbital
region: a case report and review of the literature.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod
2001;92:308–311
15 Kurihara K, Mizuseki K, Sonobe J, Yanagihara J.
Solitary fibrous tumor of the oral cavity. Report ofa case. Oral Surg Oral Med Oral Pathol Oral Radiol
Endod 1999;87:223–226.
16 Lukinmaa PL, Hietanen J, Warfvinge G, Sane J,Tuominen S, Henriksson V, et al. Solitary fibroustumor of the oral cavity. Clinicopathological andimmunohistochemical characterization of threeReferences
1 Alawi F, Stratton D, Freedman PD. Solitary fibroustumor of the oral soft tissues: a clinicopathologicand immunohistochemical study of 16 cases. Am JSurg Pathol 2001;25:900–910.
2 Ali SZ, Hoon V, Hoda S, Heelan R, Zakowski MF.

80

SFT of the buccal mucosa

22 Suster S, Nascimento AG, Miettinen M, Sickel JZ,
Moran CA. Solitary fibrous tumor of soft tissue: aclinicopathologic and immunohistochemical studyof 12 cases. Am J Surg Pathol 1995;19:1257–1266.
23 Yanamoto S, Kawasaki G, Mizuno A, Fujita S.
Solitary fibrous tumour of the buccal mucosa: immunohistochemical and ultrastructural observation.
Asian J Oral Maxillofac Surg 2003;15:199–204.
24 Vargas PA, Alves FA, Lopes MA, Siqueira SAC,Menezes LFC, Aldred VL, et al. Solitary fibroustumour of the mouth: report of two cases involving
the tongue and cheek. Oral Dis 2002;8:111–115.
25 Weiss SW, Goldblum JR. Enzinger and Weiss’s soft
tissue tumors. London: Mosby; 2001. p. 1021.

cases. J Oral Pathol Med 2000;29:186–192.
17 Piatteli A, Fioroni M, Rubini C. Solitary fibrous tumour of the tongue. Oral Oncol 1998;34:431–434.
18 Perez- Ordonez B, Koutlas IG, Strich E, Gilbert
RW, Jordan RCK. Solitary fibrous tumor of the oralcavity: an uncommon location for a ubiquitous neoplasm. Oral Surg Oral Med Oral Pathol Oral Raiol
Endod 1999;87:589–593.
19 Sato J, Asakura K, Yokoyama Y, Satoh M. Solitary
fibrous tumor of the parotid gland extending to theparapharyngeal space. Eur Arch Otorhinolaryngol
1998;255:18–21.
20 Shin JH, Sung IY, Suh JH, Yang SO, Jeong YK, Lee
JH, et al. Solitary fibrous tumor in the buccal space:MR findings with pathologic correlation. Am J
Neuroradiol 2001;22:1890–1892.
21 Shnayder Y, Greenfield BJ, Oweity T, Delacure MD.
Malignant solitary fibrous tumor of the tongue. AmJ Otolaryngol 2003;24:246–249.

Received July 1, 2005; accepted August 12, 2005
Correspondence: Kazuhiko Tanio, DDS, PhD

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