- Email: [email protected]
Central nervous system lymphoma associated with natalizumab
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Case Reports / Journal of Clinical Neuroscience 21 (2014) 1068–1070
ventricles, usually in an attempt to decrease elevated intracranial pressures through ventriculostomy, have been associated with cyst migration [3,4]. In this fashion it would be expected that the cyst would have migrated from its original location in the cerebral aqueduct into the third ventricle after ventricular drain placement. This case is unusual in that migration occurred in the opposite of the predicted direction, a phenomenon not illustrated in the current literature. The cyst must have been partially compressible in nature because it was able to migrate through the cerebral aqueduct, which is in accordance with the known histopathology of neurocysticercosis cysts as thin walled flexible structures. The calcifications of an involuted cyst would be substantially less compressible [2]. The simultaneous presentation of a pituitary adenoma and neurocysticercosis in this patient was coincidental but confounded the diagnosis. While there is only one reported patient with simultaneous presentation of pituitary macroadenoma and neurocysticercosis to our knowledge, there are multiple accounts of neurocysticercosis mimicking pituitary masses [5,6]. Given that pituitary macroadenoma is a common entity in the general population [7], a coincidental pituitary mass in a patient with neurocysticercosis will most likely represent a macroadenoma; however, sellar neurocysticercosis can mimic a pituitary
macroadenoma and therefore a high degree of clinical suspicion is necessary for accurate diagnosis. Conflicts of interest/disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Cuetter A, Andrews R. Intraventricular neurocysticercosis: 18 consecutive patients and review of the literature. Neurosurg Focus 2002;12: e5. [2] Kramer J, Carrazana E, Cosgrove G, et al. Transaqueductal migration of a neurocysticercus cyst. Case Report. J Neurosurg 1992;77:956–8. [3] Przybojewski S, Griffith-Richards SB, Strachan M, et al. ‘Migrating’ intraventricular neurocysticercus cyst. S Afr J Radiol 2007;11:25–6. [4] Chowdhary A, Abel TJ, Gabikian P, et al. Case report: resolution of acute hydrocephalus and migration of neurocysticercosis cyst with external ventricular drainage. Care Rep Med 2010;2010:245259. [5] Cohn-Zurita F, Guinto-Balanzar G, Pérez-Cerdán H. Neurocysticercosis associated with pituitary adenoma: case report and literature review. Cir Cir 2006;74:47–9. [6] Arriada-Mendicoa N, Celis-Lopez MA, Higuera-Calleja J, et al. Imaging features of sellar cysticercosis. AJNR Am J Neuroradiol 2003;24:1386–9. [7] Feldkamp J, Santen R, Harms E, et al. Incidentally discovered pituitary lesions: high frequency of macroadenomas and hormone-secreting adenomas – results of a prospective study. Clin Endocrinol 1999;51:109–13.
http://dx.doi.org/10.1016/j.jocn.2013.10.010
Central nervous system lymphoma associated with natalizumab Angelika Na a, Nick Hall a, Bhadrakant Kavar a, John King b,⇑ a b
Department of Neurosurgery, Royal Melbourne Hospital, Parkville, Melbourne, VIC, Australia Department of Neurology, Royal Melbourne Hospital, Grattan Street, Parkville, Melbourne, VIC 3050, Australia
a r t i c l e
i n f o
Article history: Received 13 October 2013 Accepted 18 October 2013
a b s t r a c t Patients with primary central nervous system lymphoma (PCNSL) after treatment with natalizumab have been considered co-incidental. We report another case of PCNSL in a patient where the explosive onset suggests a causal link. Ó 2013 Elsevier Ltd. All rights reserved.
Keywords: Lymphoma Multiple sclerosis Natalizumab
1. Case report A 28-year-old man with multiple sclerosis (MS) was seen in January 2013 with 1 week of confusion and increasing left arm weakness. In 2009 he presented with 3 years of leg weakness, bilateral optic disc pallor and spasticity of both legs. MRI of the brain and spinal cord and visual evoked responses confirmed the diagnosis of MS. He completed four doses of mitoxantrone 20 mg (one dose every 3 months) and was then lost to follow-up until December 2010, when he was stable. In May 2012 he returned with a left footdrop and brain MRI showed a gadolinium enhancing lesion in the right precentral gyrus but no other right frontal lesion. Because of compliance issues, he was treated with natalizumab 300 mg every 4 weeks and was well until January 2013 when he had seven doses of ⇑ Corresponding author. Tel.: +61 3 9348 2500; fax: +61 3 9348 2522. E-mail address: [email protected] (J. King).
natalizumab. Brain MRI in late January 2013 showed a large enhancing right frontal lesion with gross mass effect (Fig. 1). Biopsy revealed a diffuse large B-cell lymphoma. Immunostaining and in situ hybridization for Epstein Barr virus (EBV) were negative. EBV – viral capsid antigen immunoglobulin G (IgG) and EBV – nuclear antigen IgG were present in serum. His John Cunningham virus (JCV) and human immunodeficiency virus (HIV) serology were negative. There was no evidence of extracerebral lymphoma. Despite chemotherapy and radiotherapy he died in June 2013.
2. Discussion The first reported case of PCNSL after the use of natalizumab occurred in a 40-year-old MS patient treated with 21 infusions of natalizumab, who developed a PCNSL intermediate between high grade diffuse large B-cell lymphoma and Burkitt lymphoma, which was EBV negative [1]. An association between lymphoma and natalizumab was doubted by others because the absence of
Case Reports / Journal of Clinical Neuroscience 21 (2014) 1068–1070
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Fig. 1. (A) Axial fluid attenuated inversion recovery (FLAIR) MRI from May 2012 before starting natalizumab showing typical white matter lesions of multiple sclerosis. (B) Axial T2-weighted and (C) FLAIR MRI showing a large right frontal mass with vasogenic oedema and (D) T1-weighted MRI with gadolinium contrast from January 2013 displaying contrast enhancement.
EBV was evidence against an immunosuppression related lymphoma [2]. These authors noted another case of PCNSL in a patient with Crohn’s disease after only six infusions of natalizumab but considered this to be too short a period to link the tumour to natalizumab. They were also aware of a 44-year-old woman who was diagnosed with PCNSL after approximately three infusions of natalizumab. Phan-Ba et al. reported a 40-year-old man with a 20 year history of MS who presented acutely after only two doses of natalizumab with a PCNSL [3]. A fifth case was a 40-year-old woman with a 4 year history of MS who developed a diffuse large B-cell non-Hodgkin lymphoma after three doses of natalizumab [4]. To our knowledge, our patient is the sixth case of PCNSL reported after the use of natalizumab, totalling five patients with MS and one with Crohn’s disease. The MS patients had established disease and were unlikely to have had lymphoma wrongly diagnosed as MS. Five of the six patients had seven or fewer doses of natalizumab. Three patients had an explosive onset of their PCNSL within 3 months of starting natalizumab. In our patient prior treatment with mitoxantrone may have played a contributory role.
The incidence of PCNSL in the general population is less than 0.3/100,000 people under 45 years of age but is 3600-fold higher in the HIV population [5], and most of these tumours are EBV related. EBV appears to be present in 100% of MS patients [6]. After primary infection with EBV, the virus initiates a latent growth transforming infection causing naïve B cells to transform into proliferating blasts. In immunocompetent hosts both EBV-specific cytotoxic T lymphocytes and natural killer cells control the outgrowth of EBV transformed cells during the primary infection. Later in states of immunodeficiency transformed cells become proliferating blasts that can result in symptomatic disease such as post-transplant lymphoproliferative disease [7]. Systemic dissemination of PCNSL is rare, suggesting that the cells of origin are derived from neoplastic B lymphocytes that are eradicated from the periphery by a relatively intact immune system, but are able to proliferate in the central nervous system as a result of reduced T cell trafficking produced by natalizumab [8]. The rapid presentation after starting natalizumab in three patients further suggests that these potentially malignant B cells were in the central nervous system when therapy was started
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Case Reports / Journal of Clinical Neuroscience 21 (2014) 1070–1072
but had been held in check by the immune system until the commencement of natalizumab. The incidence and pattern of presentation in MS patients on natalizumab of this otherwise rare tumour in this age group, strongly favours a causal link. Conflicts of interest/disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References
[2] Bozic C, LaGuette J, Panzara M, et al. Natalizumab and central nervous system lymphoma: no clear association. Ann Neurol 2009;66:261–2. [3] Phan-Ba R, Bisg B, Deprez M, et al. Primary central nervous system lymphoma in a patient treated with natalizumab. Ann Neurol 2011;69:1060–1. [4] Matzke M, Schreiber S, Elolf E, et al. Natalizumab-associated central nervous system lymphoma? – Another patient. Mult Scler 2012;18:1653–4. [5] Cote TR, Manns A, Hardy C, et al. Epidemiology of brain lymphoma among people with or without acquired immunodeficiency syndrome. AIDS/cancer study group. J Natl Cancer Inst 1996;88:675–9. [6] Pakpoor J, Disanto G, Gerber JE, et al. The risk of developing multiple sclerosis in individuals seronegative for Epstein-Barr virus: a meta-analysis. Mult Scler 2013;19:162–6. [7] Volpi A, Pica F. Epstein-Barr virus and CNS infections. In: Singh SK, Ruzek D, editors. Neuroviral infections. Boca Raton, Fl: CRC Press; 2013. p. 245–72. [8] DeAngelis LM. Natalizumab: a double edged sword. Ann Neurol 2009;66:262–3.
[1] Schweikert A, Kremer M, Ringel F, et al. Primary central nervous system lymphoma in a patient treated with natalizumab. Ann Neurol 2009;66:403–6. http://dx.doi.org/10.1016/j.jocn.2013.10.018
Tenosynovial giant cell tumour of brachial plexus Joshua Mingsheng Ye a,b,⇑, Mingwei J. Ye b, Te Whiti Rogers c, Michael Gonzales c, Patrick Lo a,b a
Department of Neurosurgery, Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia Department of Surgery (RMH/WH), University of Melbourne, Parkville, VIC, Australia c Department of Pathology, Royal Melbourne Hospital, Parkville, VIC, Australia b
a r t i c l e
i n f o
Article history: Received 10 September 2013 Accepted 12 September 2013
Keywords: Benign neoplasm Brachial plexus Pigmented villonodular synovitis Tenosynovial giant cell tumour
a b s t r a c t Tenosynovial giant cell tumours (TGT) are benign tumours that arise in the synovial lining of joints, tendon sheaths and bursae. Tumours arising from the vertebral column are extremely rare, with few cases reported. In this article, we describe an unusual case of an extra-articular TGT of the brachial plexus, arising from the synovium of the vertebral facet joint. To our knowledge and after a review of the literature, this is the first patient with a TGT involving the brachial plexus. The clinical, radiological and histological features of this tumour are described together with a brief discussion of management options. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction Tenosynovial giant cell tumours (TGT) belong to a group of several closely related benign neoplasms that arise in the synovial lining of joints, tendon sheaths and bursae [1]. These lesions can be classified into localised or diffuse forms, depending on their growth characteristics. The localised type typically involves the tendon sheaths along wrists and fingers. In contrast, the diffuse form usually presents in areas adjacent to large weight-bearing joints such as the knee and ankle [2]. TGT rarely arise in the axial skeleton, with very few cases documented in the literature [3]. We describe to our knowledge the first patient with a vertebral TGT presenting as a mass in the brachial plexus. 2. Case report A 79-year-old elderly man initially developed gradual onset left arm pain and weakness. Over the next few months, he reported a rapid deterioration in arm strength despite gradual improvements in pain. There were no symptoms in the right upper limb or lower limbs. He recalled no history of recent trauma, but had a past history of Hodgkin’s lymphoma in the right supraclavicular region
⇑ Corresponding author. Tel.: +61 3 9342 7000; fax: +61 3 9342 7802. E-mail address: [email protected] (J.M. Ye).
treated by surgery and radiotherapy 30 years ago. Radiation targeting that area may not have been precise at the time of treatment and electromyography suggested radiation injury to that area, as myokymia could be detected in his left upper limb. His other significant medical history included prostate cancer diagnosed 8 years previously, which was treated with radiation therapy. Physical examination of his upper limb revealed wasting of his left triceps. Power was reduced in the left radial nerve innervated muscles to Medical Research Council grade 1. There was sensory loss over the anatomical snuff box and also sensory disturbance in the distribution of the left median nerve. Examination of right arm and lower limbs were otherwise unremarkable. Initial investigations were inconclusive. No lesions were detected on cervical spine radiographs and chest CT scan demonstrated no lesions in the left axilla. Nerve conduction studies identified a left radial mononeuropathy and myokymia in the left first dorsal interossei. Myokymia is an expected late complication of radiotherapy to the brachial plexus region but did not explain the disproportionate denervation changes of radial nerve muscles. MRI of the neck and brachial plexus was subsequently performed 1 month later which showed a complex cystic mass measuring 6.8 cm in length involving the left inferior brachial plexus as it passed across the first rib and second rib towards the axilla along the line of the neurovascular bundle, and appeared to be separate from the major veins and arteries. There was a mixture of signal intensity within the mass, but minimal surrounding oedema
Case Reports / Journal of Clinical Neuroscience 21 (2014) 1068–1070
ventricles, usually in an attempt to decrease elevated intracranial pressures through ventriculostomy, have been associated with cyst migration [3,4]. In this fashion it would be expected that the cyst would have migrated from its original location in the cerebral aqueduct into the third ventricle after ventricular drain placement. This case is unusual in that migration occurred in the opposite of the predicted direction, a phenomenon not illustrated in the current literature. The cyst must have been partially compressible in nature because it was able to migrate through the cerebral aqueduct, which is in accordance with the known histopathology of neurocysticercosis cysts as thin walled flexible structures. The calcifications of an involuted cyst would be substantially less compressible [2]. The simultaneous presentation of a pituitary adenoma and neurocysticercosis in this patient was coincidental but confounded the diagnosis. While there is only one reported patient with simultaneous presentation of pituitary macroadenoma and neurocysticercosis to our knowledge, there are multiple accounts of neurocysticercosis mimicking pituitary masses [5,6]. Given that pituitary macroadenoma is a common entity in the general population [7], a coincidental pituitary mass in a patient with neurocysticercosis will most likely represent a macroadenoma; however, sellar neurocysticercosis can mimic a pituitary
macroadenoma and therefore a high degree of clinical suspicion is necessary for accurate diagnosis. Conflicts of interest/disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References [1] Cuetter A, Andrews R. Intraventricular neurocysticercosis: 18 consecutive patients and review of the literature. Neurosurg Focus 2002;12: e5. [2] Kramer J, Carrazana E, Cosgrove G, et al. Transaqueductal migration of a neurocysticercus cyst. Case Report. J Neurosurg 1992;77:956–8. [3] Przybojewski S, Griffith-Richards SB, Strachan M, et al. ‘Migrating’ intraventricular neurocysticercus cyst. S Afr J Radiol 2007;11:25–6. [4] Chowdhary A, Abel TJ, Gabikian P, et al. Case report: resolution of acute hydrocephalus and migration of neurocysticercosis cyst with external ventricular drainage. Care Rep Med 2010;2010:245259. [5] Cohn-Zurita F, Guinto-Balanzar G, Pérez-Cerdán H. Neurocysticercosis associated with pituitary adenoma: case report and literature review. Cir Cir 2006;74:47–9. [6] Arriada-Mendicoa N, Celis-Lopez MA, Higuera-Calleja J, et al. Imaging features of sellar cysticercosis. AJNR Am J Neuroradiol 2003;24:1386–9. [7] Feldkamp J, Santen R, Harms E, et al. Incidentally discovered pituitary lesions: high frequency of macroadenomas and hormone-secreting adenomas – results of a prospective study. Clin Endocrinol 1999;51:109–13.
http://dx.doi.org/10.1016/j.jocn.2013.10.010
Central nervous system lymphoma associated with natalizumab Angelika Na a, Nick Hall a, Bhadrakant Kavar a, John King b,⇑ a b
Department of Neurosurgery, Royal Melbourne Hospital, Parkville, Melbourne, VIC, Australia Department of Neurology, Royal Melbourne Hospital, Grattan Street, Parkville, Melbourne, VIC 3050, Australia
a r t i c l e
i n f o
Article history: Received 13 October 2013 Accepted 18 October 2013
a b s t r a c t Patients with primary central nervous system lymphoma (PCNSL) after treatment with natalizumab have been considered co-incidental. We report another case of PCNSL in a patient where the explosive onset suggests a causal link. Ó 2013 Elsevier Ltd. All rights reserved.
Keywords: Lymphoma Multiple sclerosis Natalizumab
1. Case report A 28-year-old man with multiple sclerosis (MS) was seen in January 2013 with 1 week of confusion and increasing left arm weakness. In 2009 he presented with 3 years of leg weakness, bilateral optic disc pallor and spasticity of both legs. MRI of the brain and spinal cord and visual evoked responses confirmed the diagnosis of MS. He completed four doses of mitoxantrone 20 mg (one dose every 3 months) and was then lost to follow-up until December 2010, when he was stable. In May 2012 he returned with a left footdrop and brain MRI showed a gadolinium enhancing lesion in the right precentral gyrus but no other right frontal lesion. Because of compliance issues, he was treated with natalizumab 300 mg every 4 weeks and was well until January 2013 when he had seven doses of ⇑ Corresponding author. Tel.: +61 3 9348 2500; fax: +61 3 9348 2522. E-mail address: [email protected] (J. King).
natalizumab. Brain MRI in late January 2013 showed a large enhancing right frontal lesion with gross mass effect (Fig. 1). Biopsy revealed a diffuse large B-cell lymphoma. Immunostaining and in situ hybridization for Epstein Barr virus (EBV) were negative. EBV – viral capsid antigen immunoglobulin G (IgG) and EBV – nuclear antigen IgG were present in serum. His John Cunningham virus (JCV) and human immunodeficiency virus (HIV) serology were negative. There was no evidence of extracerebral lymphoma. Despite chemotherapy and radiotherapy he died in June 2013.
2. Discussion The first reported case of PCNSL after the use of natalizumab occurred in a 40-year-old MS patient treated with 21 infusions of natalizumab, who developed a PCNSL intermediate between high grade diffuse large B-cell lymphoma and Burkitt lymphoma, which was EBV negative [1]. An association between lymphoma and natalizumab was doubted by others because the absence of
Case Reports / Journal of Clinical Neuroscience 21 (2014) 1068–1070
1069
Fig. 1. (A) Axial fluid attenuated inversion recovery (FLAIR) MRI from May 2012 before starting natalizumab showing typical white matter lesions of multiple sclerosis. (B) Axial T2-weighted and (C) FLAIR MRI showing a large right frontal mass with vasogenic oedema and (D) T1-weighted MRI with gadolinium contrast from January 2013 displaying contrast enhancement.
EBV was evidence against an immunosuppression related lymphoma [2]. These authors noted another case of PCNSL in a patient with Crohn’s disease after only six infusions of natalizumab but considered this to be too short a period to link the tumour to natalizumab. They were also aware of a 44-year-old woman who was diagnosed with PCNSL after approximately three infusions of natalizumab. Phan-Ba et al. reported a 40-year-old man with a 20 year history of MS who presented acutely after only two doses of natalizumab with a PCNSL [3]. A fifth case was a 40-year-old woman with a 4 year history of MS who developed a diffuse large B-cell non-Hodgkin lymphoma after three doses of natalizumab [4]. To our knowledge, our patient is the sixth case of PCNSL reported after the use of natalizumab, totalling five patients with MS and one with Crohn’s disease. The MS patients had established disease and were unlikely to have had lymphoma wrongly diagnosed as MS. Five of the six patients had seven or fewer doses of natalizumab. Three patients had an explosive onset of their PCNSL within 3 months of starting natalizumab. In our patient prior treatment with mitoxantrone may have played a contributory role.
The incidence of PCNSL in the general population is less than 0.3/100,000 people under 45 years of age but is 3600-fold higher in the HIV population [5], and most of these tumours are EBV related. EBV appears to be present in 100% of MS patients [6]. After primary infection with EBV, the virus initiates a latent growth transforming infection causing naïve B cells to transform into proliferating blasts. In immunocompetent hosts both EBV-specific cytotoxic T lymphocytes and natural killer cells control the outgrowth of EBV transformed cells during the primary infection. Later in states of immunodeficiency transformed cells become proliferating blasts that can result in symptomatic disease such as post-transplant lymphoproliferative disease [7]. Systemic dissemination of PCNSL is rare, suggesting that the cells of origin are derived from neoplastic B lymphocytes that are eradicated from the periphery by a relatively intact immune system, but are able to proliferate in the central nervous system as a result of reduced T cell trafficking produced by natalizumab [8]. The rapid presentation after starting natalizumab in three patients further suggests that these potentially malignant B cells were in the central nervous system when therapy was started
1070
Case Reports / Journal of Clinical Neuroscience 21 (2014) 1070–1072
but had been held in check by the immune system until the commencement of natalizumab. The incidence and pattern of presentation in MS patients on natalizumab of this otherwise rare tumour in this age group, strongly favours a causal link. Conflicts of interest/disclosures The authors declare that they have no financial or other conflicts of interest in relation to this research and its publication. References
[2] Bozic C, LaGuette J, Panzara M, et al. Natalizumab and central nervous system lymphoma: no clear association. Ann Neurol 2009;66:261–2. [3] Phan-Ba R, Bisg B, Deprez M, et al. Primary central nervous system lymphoma in a patient treated with natalizumab. Ann Neurol 2011;69:1060–1. [4] Matzke M, Schreiber S, Elolf E, et al. Natalizumab-associated central nervous system lymphoma? – Another patient. Mult Scler 2012;18:1653–4. [5] Cote TR, Manns A, Hardy C, et al. Epidemiology of brain lymphoma among people with or without acquired immunodeficiency syndrome. AIDS/cancer study group. J Natl Cancer Inst 1996;88:675–9. [6] Pakpoor J, Disanto G, Gerber JE, et al. The risk of developing multiple sclerosis in individuals seronegative for Epstein-Barr virus: a meta-analysis. Mult Scler 2013;19:162–6. [7] Volpi A, Pica F. Epstein-Barr virus and CNS infections. In: Singh SK, Ruzek D, editors. Neuroviral infections. Boca Raton, Fl: CRC Press; 2013. p. 245–72. [8] DeAngelis LM. Natalizumab: a double edged sword. Ann Neurol 2009;66:262–3.
[1] Schweikert A, Kremer M, Ringel F, et al. Primary central nervous system lymphoma in a patient treated with natalizumab. Ann Neurol 2009;66:403–6. http://dx.doi.org/10.1016/j.jocn.2013.10.018
Tenosynovial giant cell tumour of brachial plexus Joshua Mingsheng Ye a,b,⇑, Mingwei J. Ye b, Te Whiti Rogers c, Michael Gonzales c, Patrick Lo a,b a
Department of Neurosurgery, Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia Department of Surgery (RMH/WH), University of Melbourne, Parkville, VIC, Australia c Department of Pathology, Royal Melbourne Hospital, Parkville, VIC, Australia b
a r t i c l e
i n f o
Article history: Received 10 September 2013 Accepted 12 September 2013
Keywords: Benign neoplasm Brachial plexus Pigmented villonodular synovitis Tenosynovial giant cell tumour
a b s t r a c t Tenosynovial giant cell tumours (TGT) are benign tumours that arise in the synovial lining of joints, tendon sheaths and bursae. Tumours arising from the vertebral column are extremely rare, with few cases reported. In this article, we describe an unusual case of an extra-articular TGT of the brachial plexus, arising from the synovium of the vertebral facet joint. To our knowledge and after a review of the literature, this is the first patient with a TGT involving the brachial plexus. The clinical, radiological and histological features of this tumour are described together with a brief discussion of management options. Ó 2013 Elsevier Ltd. All rights reserved.
1. Introduction Tenosynovial giant cell tumours (TGT) belong to a group of several closely related benign neoplasms that arise in the synovial lining of joints, tendon sheaths and bursae [1]. These lesions can be classified into localised or diffuse forms, depending on their growth characteristics. The localised type typically involves the tendon sheaths along wrists and fingers. In contrast, the diffuse form usually presents in areas adjacent to large weight-bearing joints such as the knee and ankle [2]. TGT rarely arise in the axial skeleton, with very few cases documented in the literature [3]. We describe to our knowledge the first patient with a vertebral TGT presenting as a mass in the brachial plexus. 2. Case report A 79-year-old elderly man initially developed gradual onset left arm pain and weakness. Over the next few months, he reported a rapid deterioration in arm strength despite gradual improvements in pain. There were no symptoms in the right upper limb or lower limbs. He recalled no history of recent trauma, but had a past history of Hodgkin’s lymphoma in the right supraclavicular region
⇑ Corresponding author. Tel.: +61 3 9342 7000; fax: +61 3 9342 7802. E-mail address: [email protected] (J.M. Ye).
treated by surgery and radiotherapy 30 years ago. Radiation targeting that area may not have been precise at the time of treatment and electromyography suggested radiation injury to that area, as myokymia could be detected in his left upper limb. His other significant medical history included prostate cancer diagnosed 8 years previously, which was treated with radiation therapy. Physical examination of his upper limb revealed wasting of his left triceps. Power was reduced in the left radial nerve innervated muscles to Medical Research Council grade 1. There was sensory loss over the anatomical snuff box and also sensory disturbance in the distribution of the left median nerve. Examination of right arm and lower limbs were otherwise unremarkable. Initial investigations were inconclusive. No lesions were detected on cervical spine radiographs and chest CT scan demonstrated no lesions in the left axilla. Nerve conduction studies identified a left radial mononeuropathy and myokymia in the left first dorsal interossei. Myokymia is an expected late complication of radiotherapy to the brachial plexus region but did not explain the disproportionate denervation changes of radial nerve muscles. MRI of the neck and brachial plexus was subsequently performed 1 month later which showed a complex cystic mass measuring 6.8 cm in length involving the left inferior brachial plexus as it passed across the first rib and second rib towards the axilla along the line of the neurovascular bundle, and appeared to be separate from the major veins and arteries. There was a mixture of signal intensity within the mass, but minimal surrounding oedema