VOLUME
33
䡠
NUMBER
5
䡠
FEBRUARY
10
2015
JOURNAL OF CLINICAL ONCOLOGY
Merkel Cell Carcinoma on a Sternotomy Scar: Atypical Clinical Presentation Case Report An 85-year-old man was admitted to the plastic surgery department in August 2010, complaining of a 6-month history of a firm, reddish, slow-growing skin nodule of 5 ⫻ 3 cm on a sternotomy scar. The nodule bled frequently, and resided at the height of the third intercostal space (Fig 1). It was associated with a hard, palpable, left axillary subcutaneous lump of 3 cm in diameter. The patient’s medical history included two myocardial infarctions (1982 and 1988), coronary artery bypass surgery in 1988, an episode of ventricular fibrillation and subsequent pacemaker implant in 2006, hypertension, dyslipidemia, and hepatitis C seropositivity. The patient received radiotherapy for prostatic cancer in 2001, and in 1997, squamous cell carcinomas (SCC) were removed from the left leg and right temple. Total node ultrasounds were taken, which identified a 2.4 ⫻ 1.5 ⫻ 1.8 cm pathologic left axilla lymph lesion. The lesion was surgically removed to a 2.5 cm macroscopically disease-free skin margin reaching the fascia, together with excisional biopsy of the enlarged axillary lymph node. Intraoperative frozen sections were taken from the margins to ascertain complete resection of the neoplasm, and the defect was repaired with a local rhomboid skin flap. All specimens were sent to the pathologist for examination; histopathology revealed a Merkel cell carcinoma. On immunochemistry analysis, tumor cells were positive for CD56 (neural cell adhesion molecule), with areas of necrosis and mixoid degeneration (Fig 2A). Ki67 nuclear antigen immunostaining showed small cells with scarce cytoplasm and round nuclei, with high expression of Ki67 (80%) (Fig 2B), confirming active
Fig 1. e22
© 2014 by American Society of Clinical Oncology
D I A G N O S I S
I N
O N C O L O G Y
proliferation of the neoplasm. This demonstrates its aggressive clinical behavior. This tumor was poorly differentiated, as confirmed through several avenues, including focal positivity for chromogranin-A, dot spot and linear pattern positivity for pancytokeratin within solid cord, a ribbon and festoon growing pattern that is characteristic of Merkel cell carcinoma (MCC; Fig 3A), and rare focal positive elements for cytokeratin-20 (Fig 3B, yellow arrows). Thyroid transcription factor-1 evaluation was negative, excluding cutaneous metastasis from smallcell lung cancer. The affected lymph node demonstrated metastasis of an endocrine carcinoma. Total body computed tomography and repeat total node ultrasound scans did not reveal evidence of systemic involvement, nor GI, thyroid, or primary lung tumor. The patient was staged as IIIB according to American Joint Committee on Cancer’s 2009 Cancer Staging Manual.1 Because of his comorbidities, axillary dissection was delayed and the patient was referred to the oncology and radiotherapy units for further treatment. After two courses of chest and axillary radiotherapy, the patient was relapse-free through 20 months of follow-up. Discussion Cutaneous MCC was first described as a specific nosologic entity in the 1970s by Toker.2 It is a rare, aggressive skin cancer associated with a high risk of regional recurrence and distant spread, resulting in a poor survival rate. It often presents as an asymptomatic and rapidlygrowing (63%), nontender (88%), and reddish/pink (56%) cutaneous nodule that mimics other skin cancer types such as squamous or basal cell carcinoma (BCC).3,4 Neuroendocrine carcinoma of the skin occurs almost exclusively in fair-haired elderly white patients, with previous history of ultraviolet exposure, as well as immune-suppressed, malnourished patients.3,4 However, there have been cases documented in blacks and Polynesians.5-7 Recent literature has reported an equal incidence in men and women.5,8 In 2008, a new type of virus belonging to the polyomavirus family—thus named MCPyV for Merkel carcinoma polyomavirus—was found to be strongly associated with this tumor.3,4 Misdiagnosis of the MCC lesion due to similarity of other benign and malignant skin conditions is a frequent challenge in the medical literature, and this case presentation, which involved a wide range of differential diagnoses, confirmed this challenge.3,4,8,10,11 This MCC case presentation is relatively uncommon (3 cases per million people/ year), and is unique in location, especially on a surgical scar.3 Since the 19th century, scattered reports discussing skin cancer arising on scars have been revealed in the medical literature; however, they are most often related to burns or chronic ulcers.12 Slow-growing masses over a scar are frequently suggestive of SCC, but may also be associated with BCC, melanoma, or sarcoma.13 In addition, patients may exhibit skin growth due to metastasis of primary cancers such as those of the GI tract, thyroid, lung, or neuroendocrine system.14 Nodal involvement is not uncommon in both conditions. Journal of Clinical Oncology, Vol 33, No 5 (February 10), 2015: pp e22-e24
Information downloaded from jco.ascopubs.org and provided by at UNIVERSITY OF TORONTO on March 7, 2015 from Copyright © 2015 American Society of Clinical Oncology. All rights reserved. 142.150.190.39
Diagnosis in Oncology
A
B
Fig 2.
roendocrine carcinoma. The coexistence of SCC, BCC and MCC in the same lesion17 or presenting synchronously with actinic keratosis, BCC and SCC18 has been related to a pluripotent stem cell origin of these tumors. Histological differentiation of neuroendocrine carcinoma of the skin from other tumors such as undifferentiated smallcell neoplasm or anaplastic metastatic carcinomas is difficult2 and requires electron microscopy and immunohistochemical analysis.8,19 In this patient, morphological observation of the specimen excluded SCC, BCC or melanoma, whereas immunohistochemical testing was suggestive of primary neuroendocrine cancer. Wide surgical excision with a more than 2 cm margin deep to the fascia was
To our knowledge this is the first report of an MCC presenting on a scar that is unrelated to skin cancer removal or burn. Our case presented on a scar resulting from a sternotomy incision for heart surgery. A small number of reports of MCC occurring in scars of other skin neoplasms do, however, exist. Rocamora et al15 reported an MCC that occurred in scar tissue two and half years after the excision of a BCC of the nose. Patel et al16 reported a patient who presented with a BCC of the thigh, which, after several courses of radiotherapy and recurrence, slowly evolved into an MCC. The authors of both of these studies hypothesized the existence of a sub-clone of basal cells, with neuroendocrine differentiation metastasizing as a high-grade neu-
A
B
Fig 3. www.jco.org
© 2014 by American Society of Clinical Oncology
Information downloaded from jco.ascopubs.org and provided by at UNIVERSITY OF TORONTO on March 7, 2015 from Copyright © 2015 American Society of Clinical Oncology. All rights reserved. 142.150.190.39
e23
Grippaudo, Costantino, and Santanelli
performed to remove the neoplasm and the source of chronic bleeding as recommended by the literature.4,20 It was reasonable to remove the enlarged, ultrasound-confirmed, pathologic lymph node only, which is associated with less morbidity compared to complete axillary lymph node dissection. Adjuvant radiation therapy was effective to control early local recurrence since MCC is a radioresponsive tumor.4,21-24 An alternate treatment in this type of frail patient—after histological diagnosis of MCC has been established through skin biopsy—is to treat the primary site and its lymph node basin with radiotherapy alone, as described by others.24-26 In conclusion, while neuroendocrine carcinoma of the skin rarely affects the sternal region and/or develops in scar tissue, it must be suspected when evaluating a reddish, nontender, slow-growing skin lesion. In our opinion, it is always worthwhile to send scar tissue for histopathologic examination, even in the case of a surgical scar revision procedure. These concepts are particularly important for specialists in the area, including dermatologists and plastic surgeons.
Francesca R. Grippaudo, Brando Costantino, and Fabio Santanelli Sant’Andrea Hospital; “Sapienza” University of Rome, Rome, Italy
AUTHORS’ DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST
The author(s) indicated no potential conflicts of interest. REFERENCES 1. Edge SB, Byrd DR, Compton CC, et al: AJCC Cancer Staging Manual (ed 7). Chicago, IL, Springer, 2009 2. Toker C: Trabecular carcinoma of the skin. Arch Dermatol 105:107-110, 1972 3. Heath M, Jaimes N, Lemos B, et al: Clinical characteristics of Merkel cell carcinoma at diagnosis in 195 patients: The AEIOU features. J Am Acad Dermatol 58:375-381, 2008 4. The Rockville Merkel Cell Carcinoma Group: Merkel cell carcinoma: Recent progress and current priorities on etiology, pathogenesis, and clinical management. J Clin Oncol 27:4021-4026, 2009 5. Shaw JH, Rumball E: Merkel cell tumour: Clinical behaviour and treatment. Br J Surg 78:138-142, 1991 6. Silva EG, Mackay B, Goepfert H, et al: Endocrine carcinoma of the skin (Merkel cell carcinoma). Pathol Annu 19:1-28, 1984 7. Anderson LL, Phipps TJ, McCollough ML: Neuroendocrine carcinoma of the skin (Merkel cell carcinoma) in a black. J Dermatol Surg Oncol 18:375-380, 1992
8. Hitchcock CL, Bland KI, Laney RG III, et al: Neuroendocrine (Merkel cell) carcinoma of the skin: Its natural history, diagnosis, and treatment. Ann Surg 207:201-207, 1988 9. Reference deleted 10. Chen L, Zhu L, Wu J, et al: Giant Merkel cell carcinoma of the eyelid: A case report and review of the literature. World J Surg Oncol 9:58, 2011 11. Swann MH, Yoon J: Merkel cell carcinoma. Semin Oncol 34:51-56, 2007 12. Arons MS, Lynch JB, Lewis SR, et al: Scar tissue carcinoma: I. A clinical study with special reference to burn scar carcinoma. Ann Surg 161:170-188, 1965 13. Kowal-Vern A, Criswell BK: Burn scar neoplasm: A literature review and statistical analysis. Burns 31:403-413, 2005 14. Brownstein MH, Helwig EB: Metastatic tumors of the skin. Cancer 29:1298-1307, 1972 15. Rocamora A, Badía N, Vives R, et al: Epidermotropic primary neuroendocrine (Merkel cell) carcinoma of the skin with Pautrier-like microabscesses: Report of three cases and review of the literature. J Am Acad Dermatol 16:1163-1168, 1987 16. Patel R, Adsay V, Andrea A: Basal cell carcinoma with progression to metastatic neuroendocrine carcinoma. Rare Tumors 2:e8, 2010 17. Cerroni L, Kerl H: Primary cutaneous neuroendocrine (Merkel cell) carcinoma in association with squamous- and basal-cell carcinoma. Am J Dermatopathol 19:610-613, 1997 18. Aydin A, Koc¸er NE, Bekerecioglu M, et al: Cutaneous undifferentiated small (Merkel) cell carcinoma, that developed synchronously with multiple actinic keratoses, squamous cell carcinomas and basal cell carcinoma. J Dermatol 30:241-244, 2003 19. Ratner D, Nelson BR, Brown MD, et al: Merkel cell carcinoma. J Am Acad Dermatol 29:143-156, 1993 20. Assouline A, Tai P, Joseph K, et al: Merkel cell carcinoma of skin: Current controversies and recommendations. Rare Tumors 3:e23, 2011 21. Lewis KG, Weinstock MA, Weaver AL, et al: Adjuvant local irradiation for Merkel cell carcinoma. Arch Dermatol 142:693-700, 2006 22. Ashby MA, Jones DH, Tasker AD, et al: Primary cutaneous neuroendocrine (Merkel cell or trabecular carcinoma) tumour of the skin: A radioresponsive tumour. Clin Radiol 40:85-87, 1989 23. Morrison WH, Peters LJ, Silva EG, et al: The essential role of radiation therapy in securing locoregional control of Merkel cell carcinoma. Int J Radiat Oncol Biol Phys 19:583-591, 1990 24. Poulsen M: Merkel-cell carcinoma of the skin. Lancet Oncology 5:593-599, 2004 25. Pacella J, Ashby M, Ainslie J, et al: The role of radiotherapy in the management of primary cutaneous neuroendocrine tumors (Merkel cell or trabecular carcinoma): Experience at the Peter MacCallum Cancer institute (Melbourne, Australia). Int J Radiat Oncol Biol Phys 14:1077-1084, 1988 26. Mortier L, Mirabel X, Fournier C, et al: Radiotherapy alone for primary Merkel cell carcinoma. Arch Dermatol 139:1587-1590, 2003
DOI: 10.1200/JCO.2013.49.2876; published online ahead of print at www.jco.org on March 7, 2014
■ ■ ■
e24
© 2014 by American Society of Clinical Oncology
JOURNAL OF CLINICAL ONCOLOGY
Information downloaded from jco.ascopubs.org and provided by at UNIVERSITY OF TORONTO on March 7, 2015 from Copyright © 2015 American Society of Clinical Oncology. All rights reserved. 142.150.190.39
33
䡠
NUMBER
5
䡠
FEBRUARY
10
2015
JOURNAL OF CLINICAL ONCOLOGY
Merkel Cell Carcinoma on a Sternotomy Scar: Atypical Clinical Presentation Case Report An 85-year-old man was admitted to the plastic surgery department in August 2010, complaining of a 6-month history of a firm, reddish, slow-growing skin nodule of 5 ⫻ 3 cm on a sternotomy scar. The nodule bled frequently, and resided at the height of the third intercostal space (Fig 1). It was associated with a hard, palpable, left axillary subcutaneous lump of 3 cm in diameter. The patient’s medical history included two myocardial infarctions (1982 and 1988), coronary artery bypass surgery in 1988, an episode of ventricular fibrillation and subsequent pacemaker implant in 2006, hypertension, dyslipidemia, and hepatitis C seropositivity. The patient received radiotherapy for prostatic cancer in 2001, and in 1997, squamous cell carcinomas (SCC) were removed from the left leg and right temple. Total node ultrasounds were taken, which identified a 2.4 ⫻ 1.5 ⫻ 1.8 cm pathologic left axilla lymph lesion. The lesion was surgically removed to a 2.5 cm macroscopically disease-free skin margin reaching the fascia, together with excisional biopsy of the enlarged axillary lymph node. Intraoperative frozen sections were taken from the margins to ascertain complete resection of the neoplasm, and the defect was repaired with a local rhomboid skin flap. All specimens were sent to the pathologist for examination; histopathology revealed a Merkel cell carcinoma. On immunochemistry analysis, tumor cells were positive for CD56 (neural cell adhesion molecule), with areas of necrosis and mixoid degeneration (Fig 2A). Ki67 nuclear antigen immunostaining showed small cells with scarce cytoplasm and round nuclei, with high expression of Ki67 (80%) (Fig 2B), confirming active
Fig 1. e22
© 2014 by American Society of Clinical Oncology
D I A G N O S I S
I N
O N C O L O G Y
proliferation of the neoplasm. This demonstrates its aggressive clinical behavior. This tumor was poorly differentiated, as confirmed through several avenues, including focal positivity for chromogranin-A, dot spot and linear pattern positivity for pancytokeratin within solid cord, a ribbon and festoon growing pattern that is characteristic of Merkel cell carcinoma (MCC; Fig 3A), and rare focal positive elements for cytokeratin-20 (Fig 3B, yellow arrows). Thyroid transcription factor-1 evaluation was negative, excluding cutaneous metastasis from smallcell lung cancer. The affected lymph node demonstrated metastasis of an endocrine carcinoma. Total body computed tomography and repeat total node ultrasound scans did not reveal evidence of systemic involvement, nor GI, thyroid, or primary lung tumor. The patient was staged as IIIB according to American Joint Committee on Cancer’s 2009 Cancer Staging Manual.1 Because of his comorbidities, axillary dissection was delayed and the patient was referred to the oncology and radiotherapy units for further treatment. After two courses of chest and axillary radiotherapy, the patient was relapse-free through 20 months of follow-up. Discussion Cutaneous MCC was first described as a specific nosologic entity in the 1970s by Toker.2 It is a rare, aggressive skin cancer associated with a high risk of regional recurrence and distant spread, resulting in a poor survival rate. It often presents as an asymptomatic and rapidlygrowing (63%), nontender (88%), and reddish/pink (56%) cutaneous nodule that mimics other skin cancer types such as squamous or basal cell carcinoma (BCC).3,4 Neuroendocrine carcinoma of the skin occurs almost exclusively in fair-haired elderly white patients, with previous history of ultraviolet exposure, as well as immune-suppressed, malnourished patients.3,4 However, there have been cases documented in blacks and Polynesians.5-7 Recent literature has reported an equal incidence in men and women.5,8 In 2008, a new type of virus belonging to the polyomavirus family—thus named MCPyV for Merkel carcinoma polyomavirus—was found to be strongly associated with this tumor.3,4 Misdiagnosis of the MCC lesion due to similarity of other benign and malignant skin conditions is a frequent challenge in the medical literature, and this case presentation, which involved a wide range of differential diagnoses, confirmed this challenge.3,4,8,10,11 This MCC case presentation is relatively uncommon (3 cases per million people/ year), and is unique in location, especially on a surgical scar.3 Since the 19th century, scattered reports discussing skin cancer arising on scars have been revealed in the medical literature; however, they are most often related to burns or chronic ulcers.12 Slow-growing masses over a scar are frequently suggestive of SCC, but may also be associated with BCC, melanoma, or sarcoma.13 In addition, patients may exhibit skin growth due to metastasis of primary cancers such as those of the GI tract, thyroid, lung, or neuroendocrine system.14 Nodal involvement is not uncommon in both conditions. Journal of Clinical Oncology, Vol 33, No 5 (February 10), 2015: pp e22-e24
Information downloaded from jco.ascopubs.org and provided by at UNIVERSITY OF TORONTO on March 7, 2015 from Copyright © 2015 American Society of Clinical Oncology. All rights reserved. 142.150.190.39
Diagnosis in Oncology
A
B
Fig 2.
roendocrine carcinoma. The coexistence of SCC, BCC and MCC in the same lesion17 or presenting synchronously with actinic keratosis, BCC and SCC18 has been related to a pluripotent stem cell origin of these tumors. Histological differentiation of neuroendocrine carcinoma of the skin from other tumors such as undifferentiated smallcell neoplasm or anaplastic metastatic carcinomas is difficult2 and requires electron microscopy and immunohistochemical analysis.8,19 In this patient, morphological observation of the specimen excluded SCC, BCC or melanoma, whereas immunohistochemical testing was suggestive of primary neuroendocrine cancer. Wide surgical excision with a more than 2 cm margin deep to the fascia was
To our knowledge this is the first report of an MCC presenting on a scar that is unrelated to skin cancer removal or burn. Our case presented on a scar resulting from a sternotomy incision for heart surgery. A small number of reports of MCC occurring in scars of other skin neoplasms do, however, exist. Rocamora et al15 reported an MCC that occurred in scar tissue two and half years after the excision of a BCC of the nose. Patel et al16 reported a patient who presented with a BCC of the thigh, which, after several courses of radiotherapy and recurrence, slowly evolved into an MCC. The authors of both of these studies hypothesized the existence of a sub-clone of basal cells, with neuroendocrine differentiation metastasizing as a high-grade neu-
A
B
Fig 3. www.jco.org
© 2014 by American Society of Clinical Oncology
Information downloaded from jco.ascopubs.org and provided by at UNIVERSITY OF TORONTO on March 7, 2015 from Copyright © 2015 American Society of Clinical Oncology. All rights reserved. 142.150.190.39
e23
Grippaudo, Costantino, and Santanelli
performed to remove the neoplasm and the source of chronic bleeding as recommended by the literature.4,20 It was reasonable to remove the enlarged, ultrasound-confirmed, pathologic lymph node only, which is associated with less morbidity compared to complete axillary lymph node dissection. Adjuvant radiation therapy was effective to control early local recurrence since MCC is a radioresponsive tumor.4,21-24 An alternate treatment in this type of frail patient—after histological diagnosis of MCC has been established through skin biopsy—is to treat the primary site and its lymph node basin with radiotherapy alone, as described by others.24-26 In conclusion, while neuroendocrine carcinoma of the skin rarely affects the sternal region and/or develops in scar tissue, it must be suspected when evaluating a reddish, nontender, slow-growing skin lesion. In our opinion, it is always worthwhile to send scar tissue for histopathologic examination, even in the case of a surgical scar revision procedure. These concepts are particularly important for specialists in the area, including dermatologists and plastic surgeons.
Francesca R. Grippaudo, Brando Costantino, and Fabio Santanelli Sant’Andrea Hospital; “Sapienza” University of Rome, Rome, Italy
AUTHORS’ DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST
The author(s) indicated no potential conflicts of interest. REFERENCES 1. Edge SB, Byrd DR, Compton CC, et al: AJCC Cancer Staging Manual (ed 7). Chicago, IL, Springer, 2009 2. Toker C: Trabecular carcinoma of the skin. Arch Dermatol 105:107-110, 1972 3. Heath M, Jaimes N, Lemos B, et al: Clinical characteristics of Merkel cell carcinoma at diagnosis in 195 patients: The AEIOU features. J Am Acad Dermatol 58:375-381, 2008 4. The Rockville Merkel Cell Carcinoma Group: Merkel cell carcinoma: Recent progress and current priorities on etiology, pathogenesis, and clinical management. J Clin Oncol 27:4021-4026, 2009 5. Shaw JH, Rumball E: Merkel cell tumour: Clinical behaviour and treatment. Br J Surg 78:138-142, 1991 6. Silva EG, Mackay B, Goepfert H, et al: Endocrine carcinoma of the skin (Merkel cell carcinoma). Pathol Annu 19:1-28, 1984 7. Anderson LL, Phipps TJ, McCollough ML: Neuroendocrine carcinoma of the skin (Merkel cell carcinoma) in a black. J Dermatol Surg Oncol 18:375-380, 1992
8. Hitchcock CL, Bland KI, Laney RG III, et al: Neuroendocrine (Merkel cell) carcinoma of the skin: Its natural history, diagnosis, and treatment. Ann Surg 207:201-207, 1988 9. Reference deleted 10. Chen L, Zhu L, Wu J, et al: Giant Merkel cell carcinoma of the eyelid: A case report and review of the literature. World J Surg Oncol 9:58, 2011 11. Swann MH, Yoon J: Merkel cell carcinoma. Semin Oncol 34:51-56, 2007 12. Arons MS, Lynch JB, Lewis SR, et al: Scar tissue carcinoma: I. A clinical study with special reference to burn scar carcinoma. Ann Surg 161:170-188, 1965 13. Kowal-Vern A, Criswell BK: Burn scar neoplasm: A literature review and statistical analysis. Burns 31:403-413, 2005 14. Brownstein MH, Helwig EB: Metastatic tumors of the skin. Cancer 29:1298-1307, 1972 15. Rocamora A, Badía N, Vives R, et al: Epidermotropic primary neuroendocrine (Merkel cell) carcinoma of the skin with Pautrier-like microabscesses: Report of three cases and review of the literature. J Am Acad Dermatol 16:1163-1168, 1987 16. Patel R, Adsay V, Andrea A: Basal cell carcinoma with progression to metastatic neuroendocrine carcinoma. Rare Tumors 2:e8, 2010 17. Cerroni L, Kerl H: Primary cutaneous neuroendocrine (Merkel cell) carcinoma in association with squamous- and basal-cell carcinoma. Am J Dermatopathol 19:610-613, 1997 18. Aydin A, Koc¸er NE, Bekerecioglu M, et al: Cutaneous undifferentiated small (Merkel) cell carcinoma, that developed synchronously with multiple actinic keratoses, squamous cell carcinomas and basal cell carcinoma. J Dermatol 30:241-244, 2003 19. Ratner D, Nelson BR, Brown MD, et al: Merkel cell carcinoma. J Am Acad Dermatol 29:143-156, 1993 20. Assouline A, Tai P, Joseph K, et al: Merkel cell carcinoma of skin: Current controversies and recommendations. Rare Tumors 3:e23, 2011 21. Lewis KG, Weinstock MA, Weaver AL, et al: Adjuvant local irradiation for Merkel cell carcinoma. Arch Dermatol 142:693-700, 2006 22. Ashby MA, Jones DH, Tasker AD, et al: Primary cutaneous neuroendocrine (Merkel cell or trabecular carcinoma) tumour of the skin: A radioresponsive tumour. Clin Radiol 40:85-87, 1989 23. Morrison WH, Peters LJ, Silva EG, et al: The essential role of radiation therapy in securing locoregional control of Merkel cell carcinoma. Int J Radiat Oncol Biol Phys 19:583-591, 1990 24. Poulsen M: Merkel-cell carcinoma of the skin. Lancet Oncology 5:593-599, 2004 25. Pacella J, Ashby M, Ainslie J, et al: The role of radiotherapy in the management of primary cutaneous neuroendocrine tumors (Merkel cell or trabecular carcinoma): Experience at the Peter MacCallum Cancer institute (Melbourne, Australia). Int J Radiat Oncol Biol Phys 14:1077-1084, 1988 26. Mortier L, Mirabel X, Fournier C, et al: Radiotherapy alone for primary Merkel cell carcinoma. Arch Dermatol 139:1587-1590, 2003
DOI: 10.1200/JCO.2013.49.2876; published online ahead of print at www.jco.org on March 7, 2014
■ ■ ■
e24
© 2014 by American Society of Clinical Oncology
JOURNAL OF CLINICAL ONCOLOGY
Information downloaded from jco.ascopubs.org and provided by at UNIVERSITY OF TORONTO on March 7, 2015 from Copyright © 2015 American Society of Clinical Oncology. All rights reserved. 142.150.190.39
