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Intraosseous leiomyoma: A report of two cases
Joint Bone Spine 74 (2007) 389e392 http://france.elsevier.com/direct/BONSOI/
Case report
Intraosseous leiomyoma: A report of two cases Jean-Michel Laffosse a,*, Anne Gomez-Brouchet b, Ge´rard Giordano a, Nicolas Bonnevialle c, Jean Puget a a
Orthopedic Surgery and Trauma Department, Rangueil 1 Teaching Hospital, avenue Jean Poulhe`s TSA 50032, 31059 Toulouse Cedex 9, France b Pathology Department, Rangueil 1 Teaching Hospital, Toulouse, France c Orthopedic Surgery and Trauma Department, Purpan Teaching Hospital, Toulouse, France Received 20 July 2006; accepted 27 November 2006 Available online 29 May 2007
Abstract Intraosseous leiomyoma is an exceedingly rare tumor, with about 15 cases in the literature. Gradually worsening nonspecific pain is the main manifestation. A unilocular or multilocular radiolucency with a rim of sclerosis is seen on standard radiographs. The findings may simulate nonossifying fibroma of a metaphysis or histiocytofibroma of the pelvis. Neither computed tomography nor magnetic resonance imaging can establish the definitive diagnosis, which requires histological examination with immunohistochemistry stains. Intraosseous leiomyosarcoma is the main differential diagnosis. The best discriminating criterion is the mitotic index, which is less than 1 to 4 mitoses per 50 high-power fields in leiomyomas. En bloc excision with wide margins is the treatment of choice for avoiding local recurrences, which are extremely rare. Ó 2007 Elsevier Masson SAS. All rights reserved. Keywords: Leiomyoma; Angioleiomyoma; Intraosseous; Immunohistochemistry; Mitotic index
1. Introduction
2. Case 1
Leiomyomas are benign tumors composed of smoothmuscle cells. They contribute 70e80% of all benign mesenchymatous tumors. The uterus is the main site of involvement, although leiomyoma may also arise in the gastrointestinal and urinary tracts, skin, and mucous membranes. Angioleiomyoma is a variant that typically presents as a painful nodule in the skin or subcutaneous tissue. Intraosseous leiomyoma is exceedingly rare and usually primary, arising from smooth-muscle cells in vessel walls. However, two cases of intraosseous leiomyoma secondary to disseminated leiomyomatosis have been reported [1,2]. Intraosseous leiomyoma usually arises in the axial skeleton [1,3e5]. Involvement of the peripheral skeleton is exceedingly rare [2,6,7]. We describe a case of leiomyoma of the ankle and another of the pelvis. To our knowledge, these cases constitute the first reported case at the ankle and the third at the pelvis.
A 42-year-old woman presented with a 1-year history of pain in the left ankle that had worsened recently. Her medical history was unremarkable, with no previous injuries. She described mechanical pain that worsened upon walking, as well as nocturnal pain. Range of motion was normal. No evidence of local or systemic inflammation was found. Plain radiographs disclosed a multilocular radiolucency surrounded by a fine rim of sclerosis in the distal fibular metaphysis, in contact with the medial cortex (Fig. 1) (fig. S1; see the supplementary material associated with this article online). Computed tomography (CT) showed a 2-cm osteolytic lesion located within, and extending beyond, the medial cortex of the metaphysis, with homogeneous tissue density of 70 HU and no fat, fluid, or calcifications (Fig. 2). No evidence of malignancy was seen. A technetium 99m bone scan showed no hyperactive foci in the fibula or elsewhere (fig. S2). By magnetic resonance imaging (MRI), a tissue mass generating signal of muscle intensity on T1 images and high signal on T2 images with fat saturation was seen. Marked enhancement occurred
* Corresponding author. E-mail address: [email protected] (J.-M. Laffosse).
1297-319X/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2006.11.016
390
J.-M. Laffosse et al. / Joint Bone Spine 74 (2007) 389e392
Fig. 1. Plain radiograph, anteroposterior view: well-defined multilocular radiolucency rimmed with sclerosis in the distal fibular metaphysis.
after gadolinium injection (fig. S3). The surrounding muscles were displaced but not invaded. The tibia was not involved. Laboratory tests were normal, with no hypercalcemia or inflammation). Neither the patient’s age nor the site of involvement was typical for fibrous cortical defect. A surgical biopsy found a solid encapsulated tumor that did not invade the muscles or tibia. Histological examination showed a proliferation of spindle-shaped cells that were either
haphazardly distributed or arranged in bundles intersecting at right angles (fig. S4a,b). Their cytoplasm was eosinophilic and their nuclei elongated with blunt ends. No atypias or mitoses were visible. The fibrohyalin stroma contained an infiltrate of lymphocytes and plasma cells in a perivascular distribution. No necrosis was seen. Immunohistochemistry stains were positive for actin, desmin, and caldesmon. A few cells were weakly positive for protein S100. Stains were negative for cytokeratins (AE1/AE3), HMB 45, CD34, CD31, and CD68. The appearance and immunohistochemical profile of the cells indicated a benign smooth-muscle tumor. The diagnosis was intraosseous leiomyoma. Surgical treatment consisted in curettage of the cavity followed by packing with autologous cortical and cancellous iliac bone and plate fixation. Histological examination of the operative specimen confirmed the diagnosis of leiomyoma. The postoperative course was uneventful. After 6 weeks of partial protection from weight-bearing on the affected limb, the patient was able to walk and to return to work. Three months after surgery, she was free of pain upon walking and at night, and the radiographic appearance indicated complete integration of the bone graft. The plate was removed after 18 months. At last follow-up 2 years after surgery, the patient reported resuming her normal activities with no pain. There was no evidence of local recurrence. 3. Case 2 This 46-year-old man presented with a 2-year history of right hip disease that had worsened rapidly over the preceding 3 months. He reported pain in the groin while walking and standing, as well as occasional pain at night. Range of motion was normal at both hips. There was no decline in general health. He denied a history of trauma, glucocorticoid therapy, or alcohol abuse. An anteroposterior radiograph of the pelvis showed a multilocular radiolucency with a thin rim of sclerosis in the right iliopubic ramus. Calcification and septae were visible within the lesion (Fig. 3). There was no fracture. CT showed a defect surrounded by a thin rim, with no extension to the acetabulum. MRI found no evidence of spread to pelvic organs. Histological examination of a surgical biopsy specimen showed a proliferation of vascular and smooth-muscle cells (fig. S5a). Some parts of the tumor were composed of medium-sized vessels resembling capillaries and veins and other parts of small vessels producing a hemangiopericytic pattern. The vessels were surrounded by a proliferation of spindleshaped cells with no mitoses. By immunohistochemistry, these cells were positive for actin, desmin, and caldesmon (fig. S5b), whereas the vessels were positive for CD34 and CD31 (fig. S5c). The tumor was removed surgically and the cavity packed with autologous bone. No further pain occurred. At last follow-up 3 years after the procedure, there was no evidence of local recurrence. 4. Discussion
Fig. 2. Computed tomography, transverse sections: well-defined defect in the medullary and medial cortex of the lateral malleolus.
Intraosseous leiomyoma is an exceedingly rare tumor that usually arises in the axial skeleton [1,3e5]. Liang et al. [3]
J.-M. Laffosse et al. / Joint Bone Spine 74 (2007) 389e392
Fig. 3. Plain radiograph of the pelvis, anteroposterior view: multilocular radiolucency in the iliopubic ramus surrounded by a rim of sclerosis. Septae and calcifications are visible within the lesion.
identified 13 cases of oral intraosseous leiomyoma, most of which involved the mandible. A literature review retrieved 6 cases involving the skull [4]. A case of leiomyoma of the pelvis was reported [5]. In one patient, disseminated leiomyomatosis developed several years after hysterectomy for multiple leiomyomas [1]; in addition to intraosseous leiomyomas of the cervical spine, rib cage, and pelvis, she had pulmonary and subcutaneous metastases. Intraosseous leiomyoma of the peripheral skeleton is extraordinarily rare; cases have been reported at the femoral neck [2] and tibia [6], as well as a single case at the distal ulna [7]. As indicated above, two cases involving the pelvis have been described [1,5]. Nonspecific pain is the main manifestation of intraosseous leiomyoma. Plain radiographs show a unilocular or multilocular lucency rimmed by sclerosis. Calcifications may be visible within the tumor. Limited erosion of the cortex may occur. The small size of the mass and the rim of sclerosis suggest a slow rate of growth consistent with a benign tumor. In our Case #1, the location of the lesion in the metaphyseal cortex required elimination of a nonossifyng fibroma (or fibrous cortical defect), a benign tumor that develops in young adults and tends to heal over time. Neither the age of our patient nor the histological findings were in favor of nonossifying fibroma. In our Case # 2, histiocytofibroma was considered based on the pelvic location but was ruled out by histology. Intraosseous leiomyosarcoma is the main differential. Histology is the only means of establishing the definitive diagnosis. By gross examination, both primary intraosseous leiomyoma and intraosseous angioleiomyoma are firm encapsulated tumors that are pink- or brown-gray in color. Leiomyoma has been divided into three histological categories: solid leiomyoma, vascular leiomyoma (or angioleiomyoma), and epithelioid leiomyoma [8]. Solid leiomyoma contributes most cases of intraosseous leiomyoma [3,4], whereas angioleiomyoma is the most prevalent type overall [9]. Angioleiomyomas fall into three histological categories: solid (the most common type in
391
soft tissues), venous, and cavernous [10]. However, all three patterns are often present within the same tumor. Intraosseous leiomyoma exhibits the same histological features as leiomyoma at other sites. Similarly, reported cases of intraosseous angioleiomyoma showed no distinctive histological features compared to soft-tissue angioleiomyomas. Solid leiomyoma is composed of a proliferation of spindle-shaped cells arranged in thick intersecting bundles. Mitoses are very rarely seen. Angioleiomyoma contains numerous small vessels with slit-like lumina. In venous angioleiomyoma, the smooth-muscle-cell proliferation merges with the outermost layer of the thick muscular walls of vein-like vessels. In the cavernous type, dilated lumina are separated by a smooth-muscle proliferation that is difficult to distinguish from the muscular wall of the vessels. Large hyperchromatic nuclei are seen occasionally within the smooth-muscle cells. No mitoses are visible. Foci of hyalinization, calcification, myxoid change, and bleeding may be present. The definitive diagnosis rests on demonstration of the immunohistochemical profile typical for smooth-muscle cells [4,5,11,12], with positive stains for actin and desmin and negative stains for protein S100 and AE1/AE3. Vessels in angioleiomyomas stain for CD34 and CD31. Nerve fibers have been identified within leiomyomas [6,12], which explains the presence of protein S100 in our Case #1. The absence of signs of malignancy must be carefully documented in order to rule out leiomyosarcoma [13]. Well-differentiated low-grade leiomyosarcoma is the most difficult differential diagnosis [13]. Intraosseous leiomyosarcoma is an aggressive tumor that produces an ill-defined radiolucency with cortical destruction. The histological features are identical to those of soft-tissue leiomyosarcoma. Pleomorphism, atypical nuclei, numerous mitoses, and foci of necrosis are present, suggesting a malignant tumor. The mitotic index is the best marker for malignancy. Given the small number of reported cases, the diagnosis of intraosseous leiomyoma requires a mitotic index no greater than 4/50 high-power fields [13], which is the criterion used to differentiate soft-tissue leiomyoma from leiomyosarcoma. Extensive cortical excision followed by packing of the cavity with autologous cancellous bone, with or without cortical bone, is the mainstay of the treatment of intraosseous leiomyosarcoma [14]. Internal fixation is required when the residual bony defect is large. Complete excision is associated with an excellent prognosis. No cases of recurrence have been reported after complete excision of intraosseous leiomyoma [2,3,5e 7,14]. A single case of recurrence after incomplete excision was reported; the recurrence was found 2 weeks after partial removal of a leiomyoma of the palate [9].
5. Conclusion Intraosseous leiomyoma is exceedingly rare. The imaging features may suggest other diagnoses depending on the site of involvement, such as nonossifying fibroma at the metaphysis of a long bone or histiocytofibroma at the pelvis. The presence of pain militates against these diagnoses. Histological studies
392
J.-M. Laffosse et al. / Joint Bone Spine 74 (2007) 389e392
including immunohistochemical stains are crucial to confirm the diagnosis of leiomyoma and to rule out leiomyosarcoma. Supplementary material Supplementary material (Figs. S1eS5) associated with this article can be found at http://www.sciencedirect.com, at doi: 10.1016/j.jbspin.2006.11.016 References [1] Gatti J, Morvan G, Henin D, Aboulker J, Nahum H, Glowinski J. Leiomyomatosis metastasizing to the spine. A case report. J Bone Joint Surg Am 1983;65:1163e5. [2] Braun W, Kotter A, Kundel K, Wiedemann M, Wagner T. Intraosseous leiomyoma of the neck of the femur. A case report. Int Orthop 1994;18:47e9. [3] Liang H, Frederiksen N, Binnie W, Cheng Y. Intraosseous oral leiomyoma: systematic review and report of one case. Dentomaxillofac Radiol 2003;32:285e90. [4] Jeung C, Song S, Kim S, Song K. Primary leiomyoma of the temporal bone. J Korean Neurosurg Soc 2004;35:321e3.
[5] Vaillo-Vinagre A, Ballestin-Carcavilla C, Madero-Garcia S, Pastor Garcia S, Checa Garcı´a A, Martinez-Tello F. Primary angioleiomyoma of the iliac bone: clinical pathology study of one case with flow cytometric DNA content and S-phase fraction analysis. Skeletal Radiol 2000;29:181e5. [6] Tomoda K, Iyama K. A case of intraosseous angioleiomyoma. Acta Orthop Scand 1992;63:568e70. [7] Zikria B, Radevic M, Jormark S, Huvos A, Yang S. Intraosseous leiomyoma of the ulna. A case report. J Bone Joint Surg Am 2004;86-A:2522e5. [8] Enzinger F, Lattes R, Torloni H. Histological typing of soft tissue tumors. Geneva: World Health Organization; 1969. 30e1. [9] Svane TJ, Smith BR, Consentino BJ, Cundiff EJ, Ceravolo Jr JJ. Oral leiomyomas: review of literature and report of a case of palatal angioleiomyoma. J Periodontol 1986;57:433e5. [10] Hachisuga T, Hashimoto H, Enjoji M. Angioleiomyoma. A clinicopathologic reappraisal of 562 cases. Cancer 1984;54:126e30. [11] Lloria-Benet M, Bagan J, Lloria de Miguel E, Borja-Morant A, Alonso S. Oral leiomyoma: a case report. Med Oral 2003;8:215e9. [12] Fox S, Heryet A, Khong T. Angioleiomyomas: an immunohistological study. Histopathology 1990;16:495e6. [13] Jeanrot C, Ouaknine M, Anract P, Carlioz A, Forest M, Tomeno B. Le´iomyosarcome primitif osseux. Pre´sentation de 5 observations anatomocliniques et revue de la litte´rature. Rev Chir Orthop 2000;86:63e73. [14] MacLeod S, Mitchell D, Miller I. Intraosseous leiomyoma of the mandible: report of a case. Br J Oral Maxillofac Surg 1993;31:187e8.
Case report
Intraosseous leiomyoma: A report of two cases Jean-Michel Laffosse a,*, Anne Gomez-Brouchet b, Ge´rard Giordano a, Nicolas Bonnevialle c, Jean Puget a a
Orthopedic Surgery and Trauma Department, Rangueil 1 Teaching Hospital, avenue Jean Poulhe`s TSA 50032, 31059 Toulouse Cedex 9, France b Pathology Department, Rangueil 1 Teaching Hospital, Toulouse, France c Orthopedic Surgery and Trauma Department, Purpan Teaching Hospital, Toulouse, France Received 20 July 2006; accepted 27 November 2006 Available online 29 May 2007
Abstract Intraosseous leiomyoma is an exceedingly rare tumor, with about 15 cases in the literature. Gradually worsening nonspecific pain is the main manifestation. A unilocular or multilocular radiolucency with a rim of sclerosis is seen on standard radiographs. The findings may simulate nonossifying fibroma of a metaphysis or histiocytofibroma of the pelvis. Neither computed tomography nor magnetic resonance imaging can establish the definitive diagnosis, which requires histological examination with immunohistochemistry stains. Intraosseous leiomyosarcoma is the main differential diagnosis. The best discriminating criterion is the mitotic index, which is less than 1 to 4 mitoses per 50 high-power fields in leiomyomas. En bloc excision with wide margins is the treatment of choice for avoiding local recurrences, which are extremely rare. Ó 2007 Elsevier Masson SAS. All rights reserved. Keywords: Leiomyoma; Angioleiomyoma; Intraosseous; Immunohistochemistry; Mitotic index
1. Introduction
2. Case 1
Leiomyomas are benign tumors composed of smoothmuscle cells. They contribute 70e80% of all benign mesenchymatous tumors. The uterus is the main site of involvement, although leiomyoma may also arise in the gastrointestinal and urinary tracts, skin, and mucous membranes. Angioleiomyoma is a variant that typically presents as a painful nodule in the skin or subcutaneous tissue. Intraosseous leiomyoma is exceedingly rare and usually primary, arising from smooth-muscle cells in vessel walls. However, two cases of intraosseous leiomyoma secondary to disseminated leiomyomatosis have been reported [1,2]. Intraosseous leiomyoma usually arises in the axial skeleton [1,3e5]. Involvement of the peripheral skeleton is exceedingly rare [2,6,7]. We describe a case of leiomyoma of the ankle and another of the pelvis. To our knowledge, these cases constitute the first reported case at the ankle and the third at the pelvis.
A 42-year-old woman presented with a 1-year history of pain in the left ankle that had worsened recently. Her medical history was unremarkable, with no previous injuries. She described mechanical pain that worsened upon walking, as well as nocturnal pain. Range of motion was normal. No evidence of local or systemic inflammation was found. Plain radiographs disclosed a multilocular radiolucency surrounded by a fine rim of sclerosis in the distal fibular metaphysis, in contact with the medial cortex (Fig. 1) (fig. S1; see the supplementary material associated with this article online). Computed tomography (CT) showed a 2-cm osteolytic lesion located within, and extending beyond, the medial cortex of the metaphysis, with homogeneous tissue density of 70 HU and no fat, fluid, or calcifications (Fig. 2). No evidence of malignancy was seen. A technetium 99m bone scan showed no hyperactive foci in the fibula or elsewhere (fig. S2). By magnetic resonance imaging (MRI), a tissue mass generating signal of muscle intensity on T1 images and high signal on T2 images with fat saturation was seen. Marked enhancement occurred
* Corresponding author. E-mail address: [email protected] (J.-M. Laffosse).
1297-319X/$ - see front matter Ó 2007 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.jbspin.2006.11.016
390
J.-M. Laffosse et al. / Joint Bone Spine 74 (2007) 389e392
Fig. 1. Plain radiograph, anteroposterior view: well-defined multilocular radiolucency rimmed with sclerosis in the distal fibular metaphysis.
after gadolinium injection (fig. S3). The surrounding muscles were displaced but not invaded. The tibia was not involved. Laboratory tests were normal, with no hypercalcemia or inflammation). Neither the patient’s age nor the site of involvement was typical for fibrous cortical defect. A surgical biopsy found a solid encapsulated tumor that did not invade the muscles or tibia. Histological examination showed a proliferation of spindle-shaped cells that were either
haphazardly distributed or arranged in bundles intersecting at right angles (fig. S4a,b). Their cytoplasm was eosinophilic and their nuclei elongated with blunt ends. No atypias or mitoses were visible. The fibrohyalin stroma contained an infiltrate of lymphocytes and plasma cells in a perivascular distribution. No necrosis was seen. Immunohistochemistry stains were positive for actin, desmin, and caldesmon. A few cells were weakly positive for protein S100. Stains were negative for cytokeratins (AE1/AE3), HMB 45, CD34, CD31, and CD68. The appearance and immunohistochemical profile of the cells indicated a benign smooth-muscle tumor. The diagnosis was intraosseous leiomyoma. Surgical treatment consisted in curettage of the cavity followed by packing with autologous cortical and cancellous iliac bone and plate fixation. Histological examination of the operative specimen confirmed the diagnosis of leiomyoma. The postoperative course was uneventful. After 6 weeks of partial protection from weight-bearing on the affected limb, the patient was able to walk and to return to work. Three months after surgery, she was free of pain upon walking and at night, and the radiographic appearance indicated complete integration of the bone graft. The plate was removed after 18 months. At last follow-up 2 years after surgery, the patient reported resuming her normal activities with no pain. There was no evidence of local recurrence. 3. Case 2 This 46-year-old man presented with a 2-year history of right hip disease that had worsened rapidly over the preceding 3 months. He reported pain in the groin while walking and standing, as well as occasional pain at night. Range of motion was normal at both hips. There was no decline in general health. He denied a history of trauma, glucocorticoid therapy, or alcohol abuse. An anteroposterior radiograph of the pelvis showed a multilocular radiolucency with a thin rim of sclerosis in the right iliopubic ramus. Calcification and septae were visible within the lesion (Fig. 3). There was no fracture. CT showed a defect surrounded by a thin rim, with no extension to the acetabulum. MRI found no evidence of spread to pelvic organs. Histological examination of a surgical biopsy specimen showed a proliferation of vascular and smooth-muscle cells (fig. S5a). Some parts of the tumor were composed of medium-sized vessels resembling capillaries and veins and other parts of small vessels producing a hemangiopericytic pattern. The vessels were surrounded by a proliferation of spindleshaped cells with no mitoses. By immunohistochemistry, these cells were positive for actin, desmin, and caldesmon (fig. S5b), whereas the vessels were positive for CD34 and CD31 (fig. S5c). The tumor was removed surgically and the cavity packed with autologous bone. No further pain occurred. At last follow-up 3 years after the procedure, there was no evidence of local recurrence. 4. Discussion
Fig. 2. Computed tomography, transverse sections: well-defined defect in the medullary and medial cortex of the lateral malleolus.
Intraosseous leiomyoma is an exceedingly rare tumor that usually arises in the axial skeleton [1,3e5]. Liang et al. [3]
J.-M. Laffosse et al. / Joint Bone Spine 74 (2007) 389e392
Fig. 3. Plain radiograph of the pelvis, anteroposterior view: multilocular radiolucency in the iliopubic ramus surrounded by a rim of sclerosis. Septae and calcifications are visible within the lesion.
identified 13 cases of oral intraosseous leiomyoma, most of which involved the mandible. A literature review retrieved 6 cases involving the skull [4]. A case of leiomyoma of the pelvis was reported [5]. In one patient, disseminated leiomyomatosis developed several years after hysterectomy for multiple leiomyomas [1]; in addition to intraosseous leiomyomas of the cervical spine, rib cage, and pelvis, she had pulmonary and subcutaneous metastases. Intraosseous leiomyoma of the peripheral skeleton is extraordinarily rare; cases have been reported at the femoral neck [2] and tibia [6], as well as a single case at the distal ulna [7]. As indicated above, two cases involving the pelvis have been described [1,5]. Nonspecific pain is the main manifestation of intraosseous leiomyoma. Plain radiographs show a unilocular or multilocular lucency rimmed by sclerosis. Calcifications may be visible within the tumor. Limited erosion of the cortex may occur. The small size of the mass and the rim of sclerosis suggest a slow rate of growth consistent with a benign tumor. In our Case #1, the location of the lesion in the metaphyseal cortex required elimination of a nonossifyng fibroma (or fibrous cortical defect), a benign tumor that develops in young adults and tends to heal over time. Neither the age of our patient nor the histological findings were in favor of nonossifying fibroma. In our Case # 2, histiocytofibroma was considered based on the pelvic location but was ruled out by histology. Intraosseous leiomyosarcoma is the main differential. Histology is the only means of establishing the definitive diagnosis. By gross examination, both primary intraosseous leiomyoma and intraosseous angioleiomyoma are firm encapsulated tumors that are pink- or brown-gray in color. Leiomyoma has been divided into three histological categories: solid leiomyoma, vascular leiomyoma (or angioleiomyoma), and epithelioid leiomyoma [8]. Solid leiomyoma contributes most cases of intraosseous leiomyoma [3,4], whereas angioleiomyoma is the most prevalent type overall [9]. Angioleiomyomas fall into three histological categories: solid (the most common type in
391
soft tissues), venous, and cavernous [10]. However, all three patterns are often present within the same tumor. Intraosseous leiomyoma exhibits the same histological features as leiomyoma at other sites. Similarly, reported cases of intraosseous angioleiomyoma showed no distinctive histological features compared to soft-tissue angioleiomyomas. Solid leiomyoma is composed of a proliferation of spindle-shaped cells arranged in thick intersecting bundles. Mitoses are very rarely seen. Angioleiomyoma contains numerous small vessels with slit-like lumina. In venous angioleiomyoma, the smooth-muscle-cell proliferation merges with the outermost layer of the thick muscular walls of vein-like vessels. In the cavernous type, dilated lumina are separated by a smooth-muscle proliferation that is difficult to distinguish from the muscular wall of the vessels. Large hyperchromatic nuclei are seen occasionally within the smooth-muscle cells. No mitoses are visible. Foci of hyalinization, calcification, myxoid change, and bleeding may be present. The definitive diagnosis rests on demonstration of the immunohistochemical profile typical for smooth-muscle cells [4,5,11,12], with positive stains for actin and desmin and negative stains for protein S100 and AE1/AE3. Vessels in angioleiomyomas stain for CD34 and CD31. Nerve fibers have been identified within leiomyomas [6,12], which explains the presence of protein S100 in our Case #1. The absence of signs of malignancy must be carefully documented in order to rule out leiomyosarcoma [13]. Well-differentiated low-grade leiomyosarcoma is the most difficult differential diagnosis [13]. Intraosseous leiomyosarcoma is an aggressive tumor that produces an ill-defined radiolucency with cortical destruction. The histological features are identical to those of soft-tissue leiomyosarcoma. Pleomorphism, atypical nuclei, numerous mitoses, and foci of necrosis are present, suggesting a malignant tumor. The mitotic index is the best marker for malignancy. Given the small number of reported cases, the diagnosis of intraosseous leiomyoma requires a mitotic index no greater than 4/50 high-power fields [13], which is the criterion used to differentiate soft-tissue leiomyoma from leiomyosarcoma. Extensive cortical excision followed by packing of the cavity with autologous cancellous bone, with or without cortical bone, is the mainstay of the treatment of intraosseous leiomyosarcoma [14]. Internal fixation is required when the residual bony defect is large. Complete excision is associated with an excellent prognosis. No cases of recurrence have been reported after complete excision of intraosseous leiomyoma [2,3,5e 7,14]. A single case of recurrence after incomplete excision was reported; the recurrence was found 2 weeks after partial removal of a leiomyoma of the palate [9].
5. Conclusion Intraosseous leiomyoma is exceedingly rare. The imaging features may suggest other diagnoses depending on the site of involvement, such as nonossifying fibroma at the metaphysis of a long bone or histiocytofibroma at the pelvis. The presence of pain militates against these diagnoses. Histological studies
392
J.-M. Laffosse et al. / Joint Bone Spine 74 (2007) 389e392
including immunohistochemical stains are crucial to confirm the diagnosis of leiomyoma and to rule out leiomyosarcoma. Supplementary material Supplementary material (Figs. S1eS5) associated with this article can be found at http://www.sciencedirect.com, at doi: 10.1016/j.jbspin.2006.11.016 References [1] Gatti J, Morvan G, Henin D, Aboulker J, Nahum H, Glowinski J. Leiomyomatosis metastasizing to the spine. A case report. J Bone Joint Surg Am 1983;65:1163e5. [2] Braun W, Kotter A, Kundel K, Wiedemann M, Wagner T. Intraosseous leiomyoma of the neck of the femur. A case report. Int Orthop 1994;18:47e9. [3] Liang H, Frederiksen N, Binnie W, Cheng Y. Intraosseous oral leiomyoma: systematic review and report of one case. Dentomaxillofac Radiol 2003;32:285e90. [4] Jeung C, Song S, Kim S, Song K. Primary leiomyoma of the temporal bone. J Korean Neurosurg Soc 2004;35:321e3.
[5] Vaillo-Vinagre A, Ballestin-Carcavilla C, Madero-Garcia S, Pastor Garcia S, Checa Garcı´a A, Martinez-Tello F. Primary angioleiomyoma of the iliac bone: clinical pathology study of one case with flow cytometric DNA content and S-phase fraction analysis. Skeletal Radiol 2000;29:181e5. [6] Tomoda K, Iyama K. A case of intraosseous angioleiomyoma. Acta Orthop Scand 1992;63:568e70. [7] Zikria B, Radevic M, Jormark S, Huvos A, Yang S. Intraosseous leiomyoma of the ulna. A case report. J Bone Joint Surg Am 2004;86-A:2522e5. [8] Enzinger F, Lattes R, Torloni H. Histological typing of soft tissue tumors. Geneva: World Health Organization; 1969. 30e1. [9] Svane TJ, Smith BR, Consentino BJ, Cundiff EJ, Ceravolo Jr JJ. Oral leiomyomas: review of literature and report of a case of palatal angioleiomyoma. J Periodontol 1986;57:433e5. [10] Hachisuga T, Hashimoto H, Enjoji M. Angioleiomyoma. A clinicopathologic reappraisal of 562 cases. Cancer 1984;54:126e30. [11] Lloria-Benet M, Bagan J, Lloria de Miguel E, Borja-Morant A, Alonso S. Oral leiomyoma: a case report. Med Oral 2003;8:215e9. [12] Fox S, Heryet A, Khong T. Angioleiomyomas: an immunohistological study. Histopathology 1990;16:495e6. [13] Jeanrot C, Ouaknine M, Anract P, Carlioz A, Forest M, Tomeno B. Le´iomyosarcome primitif osseux. Pre´sentation de 5 observations anatomocliniques et revue de la litte´rature. Rev Chir Orthop 2000;86:63e73. [14] MacLeod S, Mitchell D, Miller I. Intraosseous leiomyoma of the mandible: report of a case. Br J Oral Maxillofac Surg 1993;31:187e8.