SPINE Volume 39, Number 24, pp E1488-E1492 ©2014, Lippincott Williams & Wilkins
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine A Case Report and Review of Literature Amey R. Savardekar, MCh,* Sachin Goudihalli, MS,* Debajyoti Chatterjee, MD,† Chirag K. Ahuja, DM,‡ and Pravin Salunke, MCh*
Study Design. Case report and review of the relevant literature. Objective. To present a case of primary spinal myoepithelioma and discuss its clinical, radiological and histopathological characteristics. We report a long-term follow-up of 5 years. Summary of Background Data. Myoepithelial neoplasms, represent a diverse morphological and biological spectrum of tumors, composed of epithelial and myoepithelial elements. Primary myoepithelioma of the bone is extremely rare and very few cases of spinal myoepitheliomas have been reported till date. Methods. A 50-year male, presenting with complaints of paraparesis and difficulty in walking, was diagnosed to have an expansile lytic lesion involving the D10 vertebral body with paraspinal extension. The patient underwent D10 laminectomy and gross total resection of the tumor. Patient's power improved postoperatively, and he returned to his full functional status. Results. Long-term follow-up of 5 years reveals 2 recurrences, despite gross total resection at the initial surgery followed by radiotherapy. Histopathology, at the third surgery, documents the transformation of myoepithelioma into myoepithelial carcinoma. Conclusion. Primary myoepithelioma of spine is very rare. Gross total resection with wide resection margins in the paraspinal region should be used to tackle this rare entity as the role of adjuvant therapy is doubtful. Long-term follow-up is a must. Key words: spinal myoepithelioma, extradural spinal lesions, primary myoepithelioma of bone, myoepithelial carcinoma, immunohistochemistry of myoepithelioma, review of literature. Level of Evidence: N/A Spine 2014;39:E1488–E1492
From the Departments of *Neurosurgery, †Pathology, and ‡Radiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. Acknowledgment date: July 21, 2014. Acceptance date: July 30, 2014. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No relevant financial activities outside the submitted work. Address correspondence and reprint requests to Amey R. Savardekar, MCh, Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India; E-mail: [email protected] DOI: 10.1097/BRS.0000000000000564
E1488
www.spinejournal.com
M
yoepithelial tumors represent a diverse morphological and biological spectrum of tumors, composed of epithelial and mesenchymal elements.1 These tumors are more commonly encountered in salivary glands or skin but can also arise in the upper airway, lung, gastrointestinal tract, breast, soft tissue, and other unusual sites including bone.1,2 Myoepithelioma of the bone is extremely rare and very few cases of primary spinal “myoepitheliomas” have been reported till date.2 We report a case of primary myoepithelioma of the dorsal spine and review the pertinent literature. Our follow-up of 5 years reveals 2 recurrences, documenting the locally aggressive nature of this entity and its eventual malignant transformation into “myoepithelial carcinoma.”
CASE REPORT A 50-year-old male presented with spastic paraparesis of 3 months duration. Magnetic resonance image showed an expansile lytic lesion involving the D10 vertebral body and its left posterolateral elements, having paravertebral and intraspinal extradural components. There was consequent thecal sac compromise [Figure 1 (a-f)]. No lesion was seen elsewhere. The differential diagnoses included plasmacytoma, chondrosarcoma, and metastasis. The patient underwent D10 laminectomy and gross total resection of the tumor. Patient’s power improved to normal postoperatively. Histopathology showed a cellular tumor in a myxoid matrix (Figure 2). Histopathology revealed myoepithelioma, with the tumor cells being immunohistochemistry (IHC) positive for cytokeratin, vimentin and S-100 and negative for epithelial membrane antigen and human melanoma black-45. Two years later, the patient presented with a recurrence and underwent laminectomy with gross total tumor resection. Postoperatively, patient showed symptomatic improvement and received radiotherapy in view of local recurrence. Three years after the second surgery, the patient presented with paraparesis (power, 2/5) and urinary incontinence. Magnetic resonance image showed 2 separate lesions—4.5 × 3.4 × 5.5 cm heterogeneously enhancing extradural lesion at D9–D11 (the original tumor site), and 3.1 × 1.3 × 1.5 cm extradural lesion at D6–D8 level causing cord compression (Figure 3). Complete excision was achieved. Postoperatively, lower limb power improved to grade 3/5. Histopathology November 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1488
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
Figure 1. MRI at presentation. The lesion is hypointense on T1-weighted image (sagittal [A], axial [D]), iso- to hyperintense on T2-weighted image (sagittal [B], axial [E]) and exhibits moderate homogenous contrast enhancement (sagittal [C], axial [F]). MRI indicates magnetic resonance imaging.
Figure 2. A, The cellular tumor arranged in sheets and cords in a myxoid background, with the cells having clear cytoplasm and mild nuclear atypia (Hematoxylin & Eosin [H&E], ×100). B, Tumor cells show strong nuclear and cytoplasmic S-100 positivity (immunohistochemistry protocol [IP], ×200). C, Tumor cells are positive for vimentin (IP, ×400). D, Tumor cells show strong cytokeratin positivity (IP, ×200). E, Ki-67 stain highlights low proliferative index of tumor cells (IP, ×400). Spine
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E1489
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1489
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
Figure 3. MRI at second recurrence. A, Sagittal STIR image demonstrating the recurrent contiguous extradural soft-tissue component at D6–D8 spinal level (top arrow) along with recurrence at the primary site (bottom arrow). B, T1-weighted postcontrast sagittal image demonstrating the extradural lesion at D6–D8 level. C, T1-weighted postcontrast axial image at the level of the arrow shown in subpart B of this figure. D, T1-weighted postcontrast sagittal image demonstrating the paraspinal recurrence at the primary site (D10 level). E, T1-weighted postcontrast axial image at the level of the arrow shown in subpart D of this figure. MRI indicates magnetic resonance imaging.
showed sheets of monomorphic cells, having plasmacytoid appearance, hyperchromatic nuclei, and frequent mitosis (1–2/high power field). Areas of myxoid degeneration were noted. IHC was positive for smooth muscle actin (SMA). Ki-67 index was 40% with evidence of infiltration into the surrounding bone and soft tissue (Figure 4). Overall features suggested myoepithelial carcinoma.
DISCUSSION Myoepithelial tumors are neoplasms, composed of varying proportions of epithelial and myoepithelial cells, that exhibit a spectrum of biological behavior, varying from benign to malignant.1 Tumors with distinct epithelial and mesenchymal phenotypes are known as pleomorphic adenoma (mixed tumor) in salivary glands and mixed tumor (chondroid syringoma) in the skin and other locations; whereas neoplasms, composed of cells that have a predominant mesenchymal phenotype, regardless of the site of origin, are known as myoepithelioma.2 E1490
www.spinejournal.com
Relatively few primary osseous myoepitheliomas have been reported, and those occurring primarily in the spine are very rare.2,3 The clinical profile, malignant potential, and IHC findings and the outcome of 4 previously reported cases, is presented in Table 1.2–4 Myoepithelial tumors usually occur in adults, with an average age of 35 years and no specific sex predilection.3 Spinal myoepitheliomas mainly occur in the fourth to fifth decades of life, with a slight predilection for females (M:F = 3:2) (Table 1). The location of spinal myoepitheliomas has been lumbar spine (2 cases), thoracic spine (2 cases), and sacrum (1 case).2–4 For myoepithelial tumors, no specific clinical or pathological features correlate with local recurrence; however, caution needs to be exercised for tumors with moderate cytological atypia because they tend to have an aggressive course.1 Because these tumors are uncommonly encountered in bone, the benefit of adjuvant radiotherapy and chemotherapy remains unclear.1 A case report of a subtotally resected November 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1490
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
Figure 4. A, Low magnification image shows a cellular tumor with myxoid background (H&E ×40). B, High magnification reveals monomorphic cells with clear cytoplasm arranged in chords (H&E ×200). C, Tumor cells show strong cytoplasmic SMA positivity (IP ×200). D, Ki-67 immunostaining showing high proliferative index (IP ×400).
TABLE 1. Literature Review of Primary Spinal Myoepitheliomas Age Malignant (yr) Sex Site of Lesion Potential
References Antonescu et al4
IHC profile
Outcome
45
F
L1 vertebra
Benign
S100+/EMA−/CK+
NA
27
F
Sacrum
NA
S100+/EMA+/vimentin+/SMA−
NA
45
F
L1 vertebra
Benign
S100+/EMA−/ vimentin+/SMA−
NED (35 mo)
Ghermandi et al
62
M
T11 vertebra
Benign
S100−/EMA+/vimentin/SMA−; Ki-67 index—12%
NED (12 mo)
Present case
50
M
T10 vertebra
Locally malignant
S100+/EMA−/vimentin+/SMA+; Ki-67 index—40%
Multiple recurrences (60 mo)
Kurzawa et al2 3
IHC indicates immunohistochemistry; EMA, epithelial membrane antigen; CK, cytokeratin; SMA, smooth muscle actin; NA, not available, NED, no evidence of disease.
myoepithelioma in the sellar region treated with subsequent radiotherapy and chemotherapy had a poor outcome.5 Spinal myoepitheliomas reported in literature till date, have had a good outcome, albeit with limited follow-up. In spite of gross total resection and postoperative radiotherapy, long-term follow-up (5 yr) revealed 2 recurrences in our case. We report the transformation of a myoepithelial tumor from benign myoepithelioma to myoepithelial carcinoma.
CONCLUSION The clinical and radiological findings for spinal myoepitheliomas are nonspecific. There are no specific differentiating features on magnetic resonance image; and they may mimic plasmacytoma, myeloma, metastasis and, even osteo/chondrosarcoma at times. Histopathology, aided by immunohistochemical and molecular techniques, is critical for establishing the correct diagnosis. Long-term follow-up is essential as these tumors may exhibit aggressive behavior. Total removal Spine
of the tumor with wide resection margins, at the first setting, should be the aim of surgery, followed by regular long-term follow-up; as the role of adjuvant therapy is doubtful, and recurrences are likely even after gross total resection.
➢ Key Points Primary myoepithelioma of the spine is extremely rare. We report transformation of a benign myoepithelioma to a myoepithelial carcinoma. Gross total resection with wide resection margins is recommended. The role of adjuvant therapy in treatment of myoepithelioma is doubtful. www.spinejournal.com
E1491
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1491
22/10/14 6:00 PM
CASE REPORT References
1. Fritchie KJ, Bauman MD, Durward QJ. Myoepithelioma of the skull: a case report. Neurosurgery 2012;71:E901–4. 2. Kurzawa P, Kattapuram S, Hornicek FJ, et al. Primary myoepithelioma of bone a report of 8 cases. Am J Surg Pathol 2013;37:960–8. 3. Ghermandi R, Pala E, Gambarotti M, et al. Myoepithelioma of the spine: first case in the literature. Eur Rev Med Pharmacol Sci 2014;18(suppl 1):66–71.
E1492
www.spinejournal.com
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
4. Antonescu CR, Zhang L, Chang NE, et al. EWSR1-POU5F1 fusion in soft-tissue myoepithelial tumors. A molecular analysis of sixtysix cases, including soft tissue, bone, and visceral lesions, showing common involvement of the EWSR1 gene. Genes Chromosomes Cancer. 2010;49:1114–24. 5. Nieder C, Schneller F, Grosu AL, et al. Radiotherapy and chemotherapy for myoepithelioma of the sellar region. Strahlenther Onkol 2005;181:260–3.
November 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1492
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine A Case Report and Review of Literature Amey R. Savardekar, MCh,* Sachin Goudihalli, MS,* Debajyoti Chatterjee, MD,† Chirag K. Ahuja, DM,‡ and Pravin Salunke, MCh*
Study Design. Case report and review of the relevant literature. Objective. To present a case of primary spinal myoepithelioma and discuss its clinical, radiological and histopathological characteristics. We report a long-term follow-up of 5 years. Summary of Background Data. Myoepithelial neoplasms, represent a diverse morphological and biological spectrum of tumors, composed of epithelial and myoepithelial elements. Primary myoepithelioma of the bone is extremely rare and very few cases of spinal myoepitheliomas have been reported till date. Methods. A 50-year male, presenting with complaints of paraparesis and difficulty in walking, was diagnosed to have an expansile lytic lesion involving the D10 vertebral body with paraspinal extension. The patient underwent D10 laminectomy and gross total resection of the tumor. Patient's power improved postoperatively, and he returned to his full functional status. Results. Long-term follow-up of 5 years reveals 2 recurrences, despite gross total resection at the initial surgery followed by radiotherapy. Histopathology, at the third surgery, documents the transformation of myoepithelioma into myoepithelial carcinoma. Conclusion. Primary myoepithelioma of spine is very rare. Gross total resection with wide resection margins in the paraspinal region should be used to tackle this rare entity as the role of adjuvant therapy is doubtful. Long-term follow-up is a must. Key words: spinal myoepithelioma, extradural spinal lesions, primary myoepithelioma of bone, myoepithelial carcinoma, immunohistochemistry of myoepithelioma, review of literature. Level of Evidence: N/A Spine 2014;39:E1488–E1492
From the Departments of *Neurosurgery, †Pathology, and ‡Radiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India. Acknowledgment date: July 21, 2014. Acceptance date: July 30, 2014. The manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No relevant financial activities outside the submitted work. Address correspondence and reprint requests to Amey R. Savardekar, MCh, Department of Neurosurgery, Postgraduate Institute of Medical Education and Research, Chandigarh, India; E-mail: [email protected] DOI: 10.1097/BRS.0000000000000564
E1488
www.spinejournal.com
M
yoepithelial tumors represent a diverse morphological and biological spectrum of tumors, composed of epithelial and mesenchymal elements.1 These tumors are more commonly encountered in salivary glands or skin but can also arise in the upper airway, lung, gastrointestinal tract, breast, soft tissue, and other unusual sites including bone.1,2 Myoepithelioma of the bone is extremely rare and very few cases of primary spinal “myoepitheliomas” have been reported till date.2 We report a case of primary myoepithelioma of the dorsal spine and review the pertinent literature. Our follow-up of 5 years reveals 2 recurrences, documenting the locally aggressive nature of this entity and its eventual malignant transformation into “myoepithelial carcinoma.”
CASE REPORT A 50-year-old male presented with spastic paraparesis of 3 months duration. Magnetic resonance image showed an expansile lytic lesion involving the D10 vertebral body and its left posterolateral elements, having paravertebral and intraspinal extradural components. There was consequent thecal sac compromise [Figure 1 (a-f)]. No lesion was seen elsewhere. The differential diagnoses included plasmacytoma, chondrosarcoma, and metastasis. The patient underwent D10 laminectomy and gross total resection of the tumor. Patient’s power improved to normal postoperatively. Histopathology showed a cellular tumor in a myxoid matrix (Figure 2). Histopathology revealed myoepithelioma, with the tumor cells being immunohistochemistry (IHC) positive for cytokeratin, vimentin and S-100 and negative for epithelial membrane antigen and human melanoma black-45. Two years later, the patient presented with a recurrence and underwent laminectomy with gross total tumor resection. Postoperatively, patient showed symptomatic improvement and received radiotherapy in view of local recurrence. Three years after the second surgery, the patient presented with paraparesis (power, 2/5) and urinary incontinence. Magnetic resonance image showed 2 separate lesions—4.5 × 3.4 × 5.5 cm heterogeneously enhancing extradural lesion at D9–D11 (the original tumor site), and 3.1 × 1.3 × 1.5 cm extradural lesion at D6–D8 level causing cord compression (Figure 3). Complete excision was achieved. Postoperatively, lower limb power improved to grade 3/5. Histopathology November 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1488
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
Figure 1. MRI at presentation. The lesion is hypointense on T1-weighted image (sagittal [A], axial [D]), iso- to hyperintense on T2-weighted image (sagittal [B], axial [E]) and exhibits moderate homogenous contrast enhancement (sagittal [C], axial [F]). MRI indicates magnetic resonance imaging.
Figure 2. A, The cellular tumor arranged in sheets and cords in a myxoid background, with the cells having clear cytoplasm and mild nuclear atypia (Hematoxylin & Eosin [H&E], ×100). B, Tumor cells show strong nuclear and cytoplasmic S-100 positivity (immunohistochemistry protocol [IP], ×200). C, Tumor cells are positive for vimentin (IP, ×400). D, Tumor cells show strong cytokeratin positivity (IP, ×200). E, Ki-67 stain highlights low proliferative index of tumor cells (IP, ×400). Spine
www.spinejournal.com
E1489
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1489
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
Figure 3. MRI at second recurrence. A, Sagittal STIR image demonstrating the recurrent contiguous extradural soft-tissue component at D6–D8 spinal level (top arrow) along with recurrence at the primary site (bottom arrow). B, T1-weighted postcontrast sagittal image demonstrating the extradural lesion at D6–D8 level. C, T1-weighted postcontrast axial image at the level of the arrow shown in subpart B of this figure. D, T1-weighted postcontrast sagittal image demonstrating the paraspinal recurrence at the primary site (D10 level). E, T1-weighted postcontrast axial image at the level of the arrow shown in subpart D of this figure. MRI indicates magnetic resonance imaging.
showed sheets of monomorphic cells, having plasmacytoid appearance, hyperchromatic nuclei, and frequent mitosis (1–2/high power field). Areas of myxoid degeneration were noted. IHC was positive for smooth muscle actin (SMA). Ki-67 index was 40% with evidence of infiltration into the surrounding bone and soft tissue (Figure 4). Overall features suggested myoepithelial carcinoma.
DISCUSSION Myoepithelial tumors are neoplasms, composed of varying proportions of epithelial and myoepithelial cells, that exhibit a spectrum of biological behavior, varying from benign to malignant.1 Tumors with distinct epithelial and mesenchymal phenotypes are known as pleomorphic adenoma (mixed tumor) in salivary glands and mixed tumor (chondroid syringoma) in the skin and other locations; whereas neoplasms, composed of cells that have a predominant mesenchymal phenotype, regardless of the site of origin, are known as myoepithelioma.2 E1490
www.spinejournal.com
Relatively few primary osseous myoepitheliomas have been reported, and those occurring primarily in the spine are very rare.2,3 The clinical profile, malignant potential, and IHC findings and the outcome of 4 previously reported cases, is presented in Table 1.2–4 Myoepithelial tumors usually occur in adults, with an average age of 35 years and no specific sex predilection.3 Spinal myoepitheliomas mainly occur in the fourth to fifth decades of life, with a slight predilection for females (M:F = 3:2) (Table 1). The location of spinal myoepitheliomas has been lumbar spine (2 cases), thoracic spine (2 cases), and sacrum (1 case).2–4 For myoepithelial tumors, no specific clinical or pathological features correlate with local recurrence; however, caution needs to be exercised for tumors with moderate cytological atypia because they tend to have an aggressive course.1 Because these tumors are uncommonly encountered in bone, the benefit of adjuvant radiotherapy and chemotherapy remains unclear.1 A case report of a subtotally resected November 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1490
22/10/14 6:00 PM
CASE REPORT
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
Figure 4. A, Low magnification image shows a cellular tumor with myxoid background (H&E ×40). B, High magnification reveals monomorphic cells with clear cytoplasm arranged in chords (H&E ×200). C, Tumor cells show strong cytoplasmic SMA positivity (IP ×200). D, Ki-67 immunostaining showing high proliferative index (IP ×400).
TABLE 1. Literature Review of Primary Spinal Myoepitheliomas Age Malignant (yr) Sex Site of Lesion Potential
References Antonescu et al4
IHC profile
Outcome
45
F
L1 vertebra
Benign
S100+/EMA−/CK+
NA
27
F
Sacrum
NA
S100+/EMA+/vimentin+/SMA−
NA
45
F
L1 vertebra
Benign
S100+/EMA−/ vimentin+/SMA−
NED (35 mo)
Ghermandi et al
62
M
T11 vertebra
Benign
S100−/EMA+/vimentin/SMA−; Ki-67 index—12%
NED (12 mo)
Present case
50
M
T10 vertebra
Locally malignant
S100+/EMA−/vimentin+/SMA+; Ki-67 index—40%
Multiple recurrences (60 mo)
Kurzawa et al2 3
IHC indicates immunohistochemistry; EMA, epithelial membrane antigen; CK, cytokeratin; SMA, smooth muscle actin; NA, not available, NED, no evidence of disease.
myoepithelioma in the sellar region treated with subsequent radiotherapy and chemotherapy had a poor outcome.5 Spinal myoepitheliomas reported in literature till date, have had a good outcome, albeit with limited follow-up. In spite of gross total resection and postoperative radiotherapy, long-term follow-up (5 yr) revealed 2 recurrences in our case. We report the transformation of a myoepithelial tumor from benign myoepithelioma to myoepithelial carcinoma.
CONCLUSION The clinical and radiological findings for spinal myoepitheliomas are nonspecific. There are no specific differentiating features on magnetic resonance image; and they may mimic plasmacytoma, myeloma, metastasis and, even osteo/chondrosarcoma at times. Histopathology, aided by immunohistochemical and molecular techniques, is critical for establishing the correct diagnosis. Long-term follow-up is essential as these tumors may exhibit aggressive behavior. Total removal Spine
of the tumor with wide resection margins, at the first setting, should be the aim of surgery, followed by regular long-term follow-up; as the role of adjuvant therapy is doubtful, and recurrences are likely even after gross total resection.
➢ Key Points Primary myoepithelioma of the spine is extremely rare. We report transformation of a benign myoepithelioma to a myoepithelial carcinoma. Gross total resection with wide resection margins is recommended. The role of adjuvant therapy in treatment of myoepithelioma is doubtful. www.spinejournal.com
E1491
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1491
22/10/14 6:00 PM
CASE REPORT References
1. Fritchie KJ, Bauman MD, Durward QJ. Myoepithelioma of the skull: a case report. Neurosurgery 2012;71:E901–4. 2. Kurzawa P, Kattapuram S, Hornicek FJ, et al. Primary myoepithelioma of bone a report of 8 cases. Am J Surg Pathol 2013;37:960–8. 3. Ghermandi R, Pala E, Gambarotti M, et al. Myoepithelioma of the spine: first case in the literature. Eur Rev Med Pharmacol Sci 2014;18(suppl 1):66–71.
E1492
www.spinejournal.com
Primary Myoepithelioma of the Dorsal Spine • Savardekar et al
4. Antonescu CR, Zhang L, Chang NE, et al. EWSR1-POU5F1 fusion in soft-tissue myoepithelial tumors. A molecular analysis of sixtysix cases, including soft tissue, bone, and visceral lesions, showing common involvement of the EWSR1 gene. Genes Chromosomes Cancer. 2010;49:1114–24. 5. Nieder C, Schneller F, Grosu AL, et al. Radiotherapy and chemotherapy for myoepithelioma of the sellar region. Strahlenther Onkol 2005;181:260–3.
November 2014
Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. SPINE140907_LR E1492
22/10/14 6:00 PM
