Intra-articular fibroma of tendon sheath in the temporomandibular joint

Intra-articular fibroma of tendon sheath in the temporomandibular joint Tie-Jun Li, D D S , MDentSc, PhD, a Motoo Kitano, DDS, PhD, b Masazumi Tsuneyoshi, MD, PhD, c Satoru Sonoda, DDS, d Tamotsu Mimura, DDS, PhD, e Kagoshima, Japan KAGOSHIMA UNIVERSITY DENTAL SCHOOL, KAGOSHIMA, JAPAN,AND KYUSHU UNIVERSITY, FUKUOKA, JAPAN Fibroma of tendon sheath is an uncommon soft tissue tumor. The first case involving the temporomandibular joint is reported here. The patient presented with chronic clicking, pain, and swelling of the right temporomandibular joint associated with restricted jaw opening. Histologic, immunocytochemical, and ultrastructural features of the intra-articular tumor were identical to fibroma of tendon sheath. The variability of symptoms and the diagnostic problems 3resented by this tumor are discussed. (Oral

Surg Oral Med Oral Pathol Oral Radiol Endod 1997;84:407-10)

F i b r o m a of tendon sheath (FTS) is a rare benign tumor described initially by Geschickter and C o p e l a n d I in 1949. There was no further d o c u m e n t a t i o n of this tumor until 1979, when Chung and Enzinger 2 presented detailed clinicopathologic findings in a study of 138 cases. The tumor consists of a s l o w - g r o w i n g dense fibrous nodule that is firmly attached to tendon sheath, and it most frequently involves the fingers, hands, and wrist. Intra-articular l o c a l i z a t i o n of the tumor is extremely rare, and to our knowledge, only one case has been r e c e n t l y r e p o r t e d in the knee joint. 3 Temporomandibular joint (TMJ) involvement b y this tumor has not been previously documented. We report here a case of histologically verified fibroma of tendon sheath with an intra-articular location in the TMJ. I m m u n o c y t o c h e m i c a l and ultrastructural features of this case are also presented.

Fig. 1. Magnenc resonance imaging of the right TMJ demonstrating an intraarticular soft tissue mass (arrowheads)causing displacement and cortical bone erosion of the condyle.

CASE REPORT A 42-year-old Japanese man was referred to our hospital with complaints of fullness and pain in the right TMJ. He had an approximately 20-year history of clicking and mild pain in the right joint, arid the symptoms had been worsening for the last 6 months. He had no history of trauma to the mandible and/or TMJ or systemic joint diseases. Physical examination disclosed diffuse swelling and pain of the right TMJ region. There was no erythema of the overlying skin. His maximum incisal opening was 38 mm, and crepitus in the right TMJ aResearch Fellow, Department of Oral Pathology, Kagoshima University Dental School, Kagoshima, Japan. bprefessor and Head, Department of Oral Pathology, Kagoshima University Dental School, Kagoshima, Japan. cprofessor and Head, Second Department of Pathology, Faculty of Medicine, Kyushn University, Fukuoka, Japan. dLecturer, Department of Oral Surgery, Kagoshima University Dental School, Kagoshima, Japan. eAssociate Professor, Department of Oral Surgery, Kagoshima University Dental School, Kagoshima, Japan. Received for publication Jan. 28, 1997; accepted for publication June 5, 1997. Copyright © 1997 by Mosby-Year Book, Inc. 1079-2104/97/$5.00 + 0 7/14/84181

was detected, with deviation toward the left side on opening. Oral examination revealed a marked open bite on the right side. Radiographic examination including tomography, computed tomography (CT) and magnetic resonance imaging (MRI) showed a well-demarcated mass in the upper joint compartment of the right TMJ causing anteroinferior displacement of the condyle and superficial cortical bone erosion of both the condyle and fossa (Fig. 1). A preliminary diagnosis of benign soft tissue tumor of the right TMJ was made. The right joint was exposed from a lateral approach, and after incision of the capsule, a well-circumscribed tumor was disclosed within the upper joint cavity. The tumor was firmly attached to the synovial membrane of the anterior part of the capsule. Part of the affected disk was excised to gain assess to the deeper portions of the tumor, and the mass was then removed together with the attached synovial membrane. Postoperative healing was uneventful and TMJ function improved gradually with time. At 1-year follow-up, the incisal opening had increased to 45 ram. Clicking and pain were not evident on jaw opening, and normal occlusion was seen. There was no sign of recurrence. 407

408

gi et al.

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY October 1997

Fig. 2. Histologic features of the lesion. A, Well-circumscribed mass made up of closely aggregated spindle cells in a collagenous matrix. Dilated vascular channels and elongated slit-like spaces (arrows) are prominent. (Hematoxylin-eosin stain; original magnification xl0.) B, The central collagenized area with few stromal cells, broad hyalinized collagen bands, and vascular slits is in contrast to the peripheral cellular area C, with a vaguely storiform pattern. (Hematoxylin-eosin stain; original magnification x50.) D, Immunostaining of smooth muscle actin is seen in the cytoplasm of many spindle-shaped tumor cells. (Original magnification xl60.)

PATHOLOGIC FINDINGS On gross examination, the tumor was firm or rubbery, ovalshaped, and well circumscribed, measuring 30 x 30 x 20 mm. The mass was attached to fragments of synovium. On sectioning, it had a uniform yellowish-white appearance. Histologically, the tumor was sharply demarcated and mainly composed of fibroblast-like cells and collagenous stroma interspersed with numerous medium-sized vessels. Elongated cleft-like spaces devoid of an endothelial lining were also seen in areas (Fig. 2, A), The degree of collagenization and cellularity varied in different areas of the lesion. The central part of the tumor consisted of a poorly cellular collagenous matrix, showing broad eosinophilic areas similar to the collagen of a keloid. In these areas, scattered spindleshaped or stellate cells and narrow vessels were enclosed by the collagen matrix (Fig. 2, B). Foci of myxoid change with interspersed stellate-shaped fibroblasts were seen in areas. The peripheral zone was generally more cellular and contained slit-like or dilated vascular spaces. The slender, spindle-shaped cells contained an elongated nucleus. Focally, aggregated spindle cells sometimes appeared to form a vaguely storiform pattern (Fig. 2, C). There was a gradual

transition between the poorly cellular hyalinized collagenous central areas and more cellular peripheral areas. For immunocytochemical pbenotyping, tissue sections were stained for vimentin (Dako, 1/10), desmin (Dako, 1/50), smooth muscle actin (Dako, 1/100), S-100 protein (Dako, 1/100), and Factor VIII-related antigen (Dako, 1/100). The spindle-shaped tumor cells, particularly in the peripheral cellular areas, stained for vimentin and smooth muscle actin (Fig. 2, D) but were negative for other markers. The endothelial cells of the slit-like vessels stained positively for Factor VIII. Ultrastructurally, spindle and stellate cells were scattered in the collagen matrix. These cells had oval nuclei and smooth to deeply convoluted nuclear membranes. The chromatin was finely granular and a prominent nucleolus was occasionally seen. The cytoplasm often contained abundant microfilaments with prominent periodic densities. These microfilament bundles were located in the periphery beneath the plasma membrane and arranged parallel to the long axis of the cells (Fig. 3, A). These features were identical to the so-called myofibroblast. Rough endoplasmic reticulum with dilated cisternae was prominent in most cells. Golgi zones and micropinocytotic vesicles were also locally evident.

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY

Li et al. 409

Volume 84, Number 4

Fig. 3. A, Electron micrograph showing a spindle-shaped tumor cell with a convoluted nucleus (N) and actintype microfilament bundles (F) with prominent periodic densities (arrows) just beneath the plasma membrane. (Original magnification x 15,000.) B, Desmosome-like junctions (arrowheads) are occasionally seen between these cells. (Original magnification x26,000.)

Desmosome-like junctions were occasionally seen between these cells (Fig. 3, B).

DISCUSSION FTS is one of the benign tumors or tumor-like lesions that arise from the synovium. Other benign tumors of synovial origin are chondroma of the tendon sheath, synovial chondromatosis, synovial hemangioma, and giant-cell tumor. 4 Although there have been occasional reports of TMJ involvement b y synovial chondromatosis 5,6 and giant-cell tumor, 7 fibroma of tender sheath has not been previously reported in the TMJ. The clinical signs and symptoms of the present case suggested TMJ dysfunction. Imaging studies including CT and MRI helped greatly in the present case for the identification of an intra-articular soft tissue tumor in the TMJ. The histologic features of the present tumor were identical to FTS. The tumor was well circumscribed and consisted of a dense collagenous stroma containing spindle-shaped cells and slit-like blood vessels. Of particular interest was the nature of these fibroblast-like cells in the lesion. Immunoreactivity for actin and the presence of actin-type microfilament bundles in the cytoplasm of these cell indicated that they were myofibroblasts, a consistent cellular component reported in FTS occurring in other parts of the body. 2,3,8-1° Myofibroblasts combine the features of fibroblasts and smooth muscle cells. They exhibit nuclear indentations and folds, bundles of cytoplasmic microfilaments arranged parallel to the long axis of the cell, dense bodies, surface differentiation with desmosomes and hemidesmosomes, abundant rough endoplasmic reticulum, and pinocytotic vesicles. 1~ Myofibroblasts have been identified in a variety of tissues and lesions, the majority of which have been non-neoplastic and fre-

quently of a proposed reactive nature. 12Among the neoplasms described as containing myofibroblasts, most have been benign or of low-grade malignancy. 1~ Although the histologic features of FTS are usually characteristic, the spectrum of changes observed in FTS could sometimes overlap with other tumors and tumorlike lesions, such as giant cell tumor of tendon sheath, nodular fasciitis, fibrous histiocytoma, etc. Giant cell tumor is the most common benign tumor of the tendon sheath and synovium. 4 It is clinically and macroscopically similar to FTS, but the two lesions can be easily distinguished microscopically in most cases. Giant cell tumor may also contain some fibroblast-like and myofibroblast-like cells but is usually dominated by proliferating synovial cells, foamy histiocytes, and osteoclastlike giant cells. 2,8 Histologic distinction between cellular or myxoid variants of FTS and nodular fasciitis may also be difficult. Nodular fasciitis, however, appears suddenly, grows rapidly, and usually attains its full size in 3 to 6 weeks. 2,3 FTS is, in contrast, usually slow-growing. Furthermore, lesions of nodular fasciitis are poorly circumscribed as compared with the usual examples of FTS. 9 Confusion may also be possible between a more cellular form of FFS and fibrous histiocytoma. However, distinction will be readily apparent if attention is paid to the distinctly circumscribed or lobulated appearance and the gradual transition between cellular and more hyalinized collagenous areas in FTS. 2 Whether fibroma of tendon sheath is a reactive fibrosing process or a true neoplasm is still not clear. 4 Repeated minor trauma has been considered as a possible causative factor. 3A° In the present case, there was no recorded history of trauma to the TMJ region. However, the patient had had a 20-year chronic course of TMJ clicking and pain, suggesting the initial presence of

410 gi etal.

ORAL SURGERY ORAL MEDICINE ORAL PATHOLOGY October 1997

joint dysfunction and/or internal joint derangement. It is possible that chronic friction or other forms of minor injury caused by the condyle-disk incoordination could have contributed to the subsequent development of the tumor. This could explain the intra-articular localization of the present lesion. Pulitzer et al. 9 have suggested that FTS may represent a group of pathogenetically diverse lesions with similar clinical and pathologic features, and some of them may be derived from mesenchymal structures other than tendon sheaths. The present intraarticular FTS appeared to arise from the synovial membrane o f the joint capsule, as the tumor was firmly attached to the synovial structure of the TMJ. From a practical point of view, FTS has no aggressive potential. Recurrence, if it occurs, is most likely the result in incomplete excision of the lesion. 2,3,8-1° There is no evidence that it can undergo malignant change. As it occurs in the TMJ, a major consideration would be the postoperative functional restoration of the joint, in addition to the requirement of complete excision of the tumor and affected tissues to prevent recurrence. That emphasizes the importance of early diagnosis and prompt therapy. However, TMJ involvement with a slow-growing tumor such as FTS could present with nonspecific symptoms of TMJ dysfunction, and the possibility of neoplastic diseases may be overlooked initially.

2. Chung EB, Enzinger FM. Fibroma of tendon sheath. Cancer 1979;44:1945-54. 3. Pinar H, Ozkan M, Ozaksoy D, Pabuccuoglu U, Akseki D, Karaogkan O. Intraarticular fibroma of the tendon sheath of the knee. Arthroscopy 1995; 11:608-1 I. 4. Enzinger FM, Weiss SW. Soft tissue tumors. 2nd ed. St. Louis: Mosby; 1988. p. 638-58. 5. Thompson K, Schwartz HC, Miles JW. Synovial chondromatosis of the temporomandibular joint presenting as a parotid mass: possibility of confusion with benign mixed tumor. Oral Surg Oral Med Oral Pathol 1986;62:377-80. 6. Holmlund A, Reinholt F, Bergstedt H. Synovial chondromatosis of the temporomandibularjoint. Report of a case. Oral Surg Oral Med Oral Pathol 1992;73:266-8. 7. Holscher AH, Rahlf G, Stennert E, Schaner A. Giant cell tumor of tendon sheath in association with synovial chondroma. An unusual tumor-combination at the temporomandibular joint. Laryngol Rhinol Otol Stuttg 1978;57:904-7. 8. Millon SJ, Bush DC, Garbes AD. Fibroma of tendon sheath in the hand. J Hand Surg Am 1994;19:788-93. 9. Pulitzer DR, Martin PC, Reed RJ. Fibroma of tendon sheath. A clinicopathologic study of 32 cases. Am J Surg Pathol 1989;13:472-9. 10. Lundgren LG, Kindblom LG. Fibroma of tendon sheath. A light and electron microscopic study of 6 cases. Acta Pathol Microbiol Immunol Scand A 1984;92:401-9. 11. Gabbiani G, Ryan GB, Majno G. Presence of modified fibroblasts in granulation tissue, their possible role in wound contraction. Experientia 1971;27:549-50. 12. Ghadially FN. Ultrastructural pathology of the cell and matrix. 2nd ed. London: Butterworths; 1982. p. 654-63. 13. Seemayer TA, Lagace R, Schurch W, Thelmo WL. The myofibroblast: biologic, pathologic and theoretical considerations. Pathol Annu 1980;15(Ptl):443-70.

REFERENCES 1. Geschickter CF, Copeland MM. Tumors of bone. 3rd ed. Philadelphia: JB Lippincott; 1949. p. 693-5.

Reprint requests: Prof. M Kitano, DDS, PhD Department of Oral Pathology Kagoshima University Dental School Sakuragaoka 8-chome Kagoshima-shi 890 Japan