OTHER
The Clinical Respiratory Journal
Inflammatory nodule mimicking a phrenic neoplasm Jacopo Vannucci1, Elisa Scarnecchia1, Rachele Del Sordo2, Lucio Cagini1 and Francesco Puma1 1 Thoracic Surgery Unit, University of Perugia Medical School, Perugia, Italy 2 Institute of Pathological Anatomy and Histology, University of Perugia Medical School, Perugia, Italy
Abstract Background and Aims: Isolated phrenic nerve nodule is usually a primitive tumour. Surgery is diagnostic and therapeutic at the same time. We report the case of a completely serum-negative Caucasian male with a right diaphragmatic relaxation associated to an isolated small nodule of the phrenic nerve. Methods: The patient was referred to our unit complaining shortness of breath and progressive fatigue. A standard chest X-ray showed right diaphragmatic palsy; chest scanning revealed a nodular lesion belonging to the right phrenic nerve. Positron emission tomography was negative for glucose uptake. The preoperative diagnosis of primitive neurogenic tumour was thus supposed, and the patient treated by the lesion’s surgical resection along with diaphragmatic plication. Result: Histopathological examination revealed an idiopathic inflammatory nodule of the phrenic nerve. Conclusion: Such condition has not previously been reported in the literature among the possible aetiology of a diaphragmatic relaxation. Please cite this paper as: Vannucci J, Scarnecchia Scarnecchia E, E, Del Sordo R, Cagini L and Puma Please F. Inflammatory Inflammatorynodule nodulemimicking mimickingaaphrenic phrenicneoplasm. neoplasm.Clin ClinRespir RespirJJ2016; 2014;10: ••: ••–••. F. 400– DOI:10.1111/crj.12195. 403. DOI:10.1111/crj.12195.
Conflict of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article.
Introduction Neoplastic etiology of unilateral diaphragmatic paralysis is usually related to advanced secondary cancer and very rarely to a primary phrenic nerve tumour (1). Diaphragmatic relaxation secondary to inflammatory disease of the nerve has been described and is generally attributed to viral or bacterial infections or to a nonspecific neuropathy (2). To our knowledge, an idiopathic inflammatory nodule of the phrenic nerve causing diaphragmatic relaxation has never been reported in the literature.
Case report A healthy and productive 54-year-old man was referred to our service with complaints of 2-month
The 400Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
Key words diaphragm – mediastinum – phrenic nerve – respiratory insufficiency Correspondence Jacopo Vannucci, MD, Thoracic Surgery Unit, Ospedale S. Maria della Misericordia, 06134 Perugia, Italy. Tel: +39 075 5782267 Fax: +39 075 5782600 email: [email protected] Received: 03 January 2014 Revision requested: 27 June 2014 Accepted: 01 August 2014 DOI:10.1111/crj.12195 Authorship and contributorship JV and FP wrote the article. ES and LC collected data, images and follow-up information. JV and LC selected references. ROS reported and performed the surgical pathology investigation. Ethics The study was approved by the ethics committee and was performed in accordance to the Declaration of Helsinki. Informed consent has been obtained.
mild shortness of breath and increasing fatigue. The patient had no comorbidities and was taking no chronic therapy. No recent traumas, surgery, infectious disease or systemic syndromes were reported. No episode of fever or acute symptoms was recorded in the recent past period. The chest X-ray showed right diaphragmatic relaxation (Fig. 1 – left side). The computed tomography scan (CT) confirmed the unilateral right diaphragmatic palsy and showed an isolated, 13 mm nodular tumour, contiguous to the superior vena cava. The lesion was attributed to the right phrenic nerve; multiplanar reconstruction distinctly clarified the position and relationship of the mass (Fig. 2A). Positron emission tomography (PET) was then performed revealing no pathological 18fluorodeoxyglucose uptake of the neoplasm; PET negativity is consistent with neurogenic tumours
1 The Clinical Respiratory Journal (2016) • ISSN 1752-6981 C 2014 John Wiley & Sons Ltd V
Vannucci et al. inflammatory nodule Solitary phrenic
Solitary phrenic inflammatory nodule Vannucci et al.
Figure 1. Standard chest X-ray at diagnosis (left side) and at 3.5 years follow-up (right side).
belonging to peripheral neuronal paths. Therefore, workup was deepened to exclude systemic conditions. Immunoserology, autoimmunitary tests and infectious disease specific analysis were completely negative and ruled out any possible latent infection or subclinical rheumatic syndromes. The patient underwent respiratory function tests: mild obstructive respiratory impairment, normal emogasanalysis. In the multidisciplinary ward round, surgical intervention was chosen deeming probable the neoplastic aetiology of the diaphragmatic relaxation. Through a small right posterolateral thoracotomy, a small solid whitish nodule of the phrenic nerve was found. The lesion was situated at the anterior margin of the superior vena cava with no infiltrating feature. The tumour was excised by segmental phrenic nerve removal, and the normal chest cavity volume was restored by diaphragmatic plication. Posterolateral thoracotomy gave a good exposure of the lateral mediastinum, and the primary lesion was easily found and resected. At the same time, diaphragmatic manipulation was favoured by this incision. Normal lung deflation and free pleural space often allows to reduce incision’s length. At thoracotomy the phrenic nodule appeared to completely involve the nerve in its circum-
ference with no cleavage. Biopsy for frozen section was thus avoided for the following reasons: (i) impossibility to have a representative tissue sample without nerve damage; (ii) high probability of neural tumour (indication to have the mass removed at once avoiding morcellation); (iii) indication to segmental phrenic nerve resection considering the pre-existing diaphragm impairment; and (iv) proper tissue quantity for final surgical pathology assessment. Macroscopically, the specimen consisted of a 3-cm segment of nerve with a swelling of 0.7 × 0.5 cm (Fig. 2B). The tissue samples were fixed in 10% buffered formalin and embedded in paraffin. The 4-μm tissue sections were stained with haematoxylin and eosin. Immunostains for CD3 [Novocastra/Leica (Buffalo Groove, IL, USA), clone PS1, ready to use], CD20 (Novocastra/Leica, clone L26, ready to use) and CD34 (Novocastra/Leica, clone QBEnd/10, ready to use) were performed on selected sections. There were present, microscopically, oedema and many perivascular inflammatory infiltrations of endoneurial vessels in absence of mural fibrinoid necrosis and karyorrhexis (possible cause of PET negativity, Fig. 3A-B). The infiltrations were constituted of a mixed inflammatory cell population consisting of lymphocytes T (CD3
Figure 2. (A) Computed tomography (CT) scan of thorax and abdomen revealed a little nodular mass along the course of the right phrenic nerve, imprinting the anterior edge of superior vena cava. (B) Surgical specimen: nodular, solid, not capsulated lesion of the phrenic nerve.
The 2 Clinical Respiratory Journal (2016) • ISSN 1752-6981 C 2014 John Wiley & Sons Ltd V
401 The Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
Vannucci et al. inflammatory nodule Solitary phrenic
Solitary phrenic inflammatory nodule Vannucci et al.
Figure 3. (A) Low-power view showing a large number of perivascular inflammatory infiltrate [haematoxylin/eosin (EE) 40×]. (B) High-power view showing endoneurial vessels surrounded by lymphoplasmacytic infiltrate (EE and CD34 200×). Immunostain for CD 3 (C) and CD20 (D) shows that the perivascular inflammatory infiltrate was mainly consisting of lymphocytes T and B (200×).
expression) (Fig. 3C), B (CD20 expression) (Fig. 3D) and plasma cells. Hospital discharge occurred in day 6 after a smooth postoperative course. Two years later, the patient was controlled by chest X-ray and physical examination. The most recent chest X-ray (3.5 years follow-up, Fig. 1 – right side) shows a mild asymmetry between hemidiaphragms; this asymmetry appears to be consistent to long-term progressive flaccidity after denervation. No episodes of acute dyspnoea are reported up to date during follow-up after surgery. His condition is currently excellent. He has completely come back to normal life, full-time work and all prior activities. Subjective report of postoperative respiratory improvement was considered a sufficiently adequate descriptor by caring physician, and no functional respiratory test was thus performed after surgery.
Discussion Diaphragmatic paralysis can be caused by traumas, systemic disorders, neurological diseases, iatrogenic injury (surgery of chest and neck) and neoplastic compression/infiltration of the nerve. Phrenic nerve palsy can also be because of infectious processes (3, 4). Primitive tumour of the phrenic nerve are mostly diagnosed when a bulky disease produces compression of other mediastinal organs, while diaphragmatic dysfunction is rarely related to such neoplasms especially if they are small masses, although it is The 402Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
occasionally described in case of neurilemmoma and neurofibroma (5). The above-mentioned tumours are rare, and differential diagnosis with other neoplasms of the mediastinum involving the phrenic nerve can be difficult and often clarified only by histology (6). Infectious diseases affecting the phrenic nerve are exceptional events, and the diagnosis is sometimes obtained after a long time and ‘ex adiuvantibus’. Moreover, in a consistent number of cases, the diagnosis remains unknown especially in old patients with heavy comorbidities. Benign disorders affecting the phrenic nerve encompass Guillain-Barrè and Charcot-MarieTooth syndromes. Moreover several other peripheral neuropathies have been related to phrenic impairment but nodular isolated findings never correspond to these diagnosis (7). When a mediastinal mass is encountered, the occurrence of a small, roundish mass, slightly lateral and anatomically located on the course of the nerve, the suspicion of a phrenic nerve tumour is reasonable considering the spectrum of possibility (8). After undergoing CT scan, some imaging details and clinical features can be of help to identify the mass; the relationship between the mass and the nerve is the main attribute to be investigated. First of all, the mass can be eccentric or concentric; in case of eccentricity, the tumour is probable coming up from neuroglial cells, while concentric lesions mostly arise from neurons. Diffuse inflammatory reactions should show a concentric shape, but a sure diagnosis based on 3 The Clinical Respiratory Journal (2016) • ISSN 1752-6981 C 2014 John Wiley & Sons Ltd V
Vannucciphrenic et al. inflammatory nodule Solitary
imaging is impossible for the ruling out of a malignancy. The surgical biopsy is the only reliable technique for obtaining the definite diagnosis and therapy of that kind of single nodular lesion of the mediastinum. To the best of our knowledge, such a kind of phrenic nerve neuritis presented as a nodular mediastinal lesion has never been described before. The recent issue of the Thoracic Surgery Clinics (2) regarding the surgery of the diaphragm provides an updated collection of possible causes of unilateral phrenic palsy. In the synthetic table, all the possible reasons are listed, but any kind of ‘localised plasmacellular diffuse neuritis’ is missing and, for this reason, we have submitted this brief description.
Conclusion The occurrence of an isolated phrenic nerve nodule in a serum-negative patient can be an idiopathic inflammatory nodule even if it is really improbable. Surgery is the only invasive method to achieve a fine diagnosis in such a setting. Given the clinical and pathological facts, the aetiology remains undisclosed but treatment has been effective.
The Clinical Respiratory Journal (2016) • ISSN 1752-6981 4 C 2014 John Wiley & Sons Ltd V
Solitary phrenic inflammatory nodule Vannucci et al.
References 1. Moinuddeen K, Baltzer JW, Zama N. Diaphragmatic eventration: an uncommon presentation of a phrenic nerve schwannoma. Chest. 2001;119: 1615–6. 2. Ko AM, Darling GE. Acquired paralysis of the diaphragm. In: Darling G, Ferguson MK, editors. Thoracic Surgery Clinics. Philadelphia, Saunders-Elsevier, 2009: 501–10. 3. Oike M, Naito T, Tsukada M, et al. A case of diaphragmatic paralysis complicated by herpes zoster virus infection. Intern Med. 2012;51: 1259–63. 4. Odell JA, Kennelly K, Stauffer J. Phrenic nerve palsy and Parsonage -Turner syndrome. Ann Thorac Surg. 2011;92: 349–51. 5. Mevio E, Gorini E, Sbrocca M, et al. Unusual cases of cervical nerve schwannomas: phrenic and vagus nerve involvement. Auris Nasus Larynx. 2003;30: 209–13. 6. Smahi M, Lakaranbi M, Ouadnouni Y, et al. Intrathoracic phrenic nerve neurofibroma. Ann Thorac Surg. 2011;91: 57–8. 7. Burakgazi AZ, Höke A. Respiratory muscle weakness in peripheral neuropathies. J Peripher Nerv Syst. 2010;15(4): 307–13. 8. Le Pimpec-Barthes F, Martinod E, Riquet M, SaintBlancard P, Jancovici R. Tumors of the phrenic nerve. Rev Mal Respir. 1998;15: 93–5.
403 The Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
The Clinical Respiratory Journal
Inflammatory nodule mimicking a phrenic neoplasm Jacopo Vannucci1, Elisa Scarnecchia1, Rachele Del Sordo2, Lucio Cagini1 and Francesco Puma1 1 Thoracic Surgery Unit, University of Perugia Medical School, Perugia, Italy 2 Institute of Pathological Anatomy and Histology, University of Perugia Medical School, Perugia, Italy
Abstract Background and Aims: Isolated phrenic nerve nodule is usually a primitive tumour. Surgery is diagnostic and therapeutic at the same time. We report the case of a completely serum-negative Caucasian male with a right diaphragmatic relaxation associated to an isolated small nodule of the phrenic nerve. Methods: The patient was referred to our unit complaining shortness of breath and progressive fatigue. A standard chest X-ray showed right diaphragmatic palsy; chest scanning revealed a nodular lesion belonging to the right phrenic nerve. Positron emission tomography was negative for glucose uptake. The preoperative diagnosis of primitive neurogenic tumour was thus supposed, and the patient treated by the lesion’s surgical resection along with diaphragmatic plication. Result: Histopathological examination revealed an idiopathic inflammatory nodule of the phrenic nerve. Conclusion: Such condition has not previously been reported in the literature among the possible aetiology of a diaphragmatic relaxation. Please cite this paper as: Vannucci J, Scarnecchia Scarnecchia E, E, Del Sordo R, Cagini L and Puma Please F. Inflammatory Inflammatorynodule nodulemimicking mimickingaaphrenic phrenicneoplasm. neoplasm.Clin ClinRespir RespirJJ2016; 2014;10: ••: ••–••. F. 400– DOI:10.1111/crj.12195. 403. DOI:10.1111/crj.12195.
Conflict of interest The authors have stated explicitly that there are no conflicts of interest in connection with this article.
Introduction Neoplastic etiology of unilateral diaphragmatic paralysis is usually related to advanced secondary cancer and very rarely to a primary phrenic nerve tumour (1). Diaphragmatic relaxation secondary to inflammatory disease of the nerve has been described and is generally attributed to viral or bacterial infections or to a nonspecific neuropathy (2). To our knowledge, an idiopathic inflammatory nodule of the phrenic nerve causing diaphragmatic relaxation has never been reported in the literature.
Case report A healthy and productive 54-year-old man was referred to our service with complaints of 2-month
The 400Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
Key words diaphragm – mediastinum – phrenic nerve – respiratory insufficiency Correspondence Jacopo Vannucci, MD, Thoracic Surgery Unit, Ospedale S. Maria della Misericordia, 06134 Perugia, Italy. Tel: +39 075 5782267 Fax: +39 075 5782600 email: [email protected] Received: 03 January 2014 Revision requested: 27 June 2014 Accepted: 01 August 2014 DOI:10.1111/crj.12195 Authorship and contributorship JV and FP wrote the article. ES and LC collected data, images and follow-up information. JV and LC selected references. ROS reported and performed the surgical pathology investigation. Ethics The study was approved by the ethics committee and was performed in accordance to the Declaration of Helsinki. Informed consent has been obtained.
mild shortness of breath and increasing fatigue. The patient had no comorbidities and was taking no chronic therapy. No recent traumas, surgery, infectious disease or systemic syndromes were reported. No episode of fever or acute symptoms was recorded in the recent past period. The chest X-ray showed right diaphragmatic relaxation (Fig. 1 – left side). The computed tomography scan (CT) confirmed the unilateral right diaphragmatic palsy and showed an isolated, 13 mm nodular tumour, contiguous to the superior vena cava. The lesion was attributed to the right phrenic nerve; multiplanar reconstruction distinctly clarified the position and relationship of the mass (Fig. 2A). Positron emission tomography (PET) was then performed revealing no pathological 18fluorodeoxyglucose uptake of the neoplasm; PET negativity is consistent with neurogenic tumours
1 The Clinical Respiratory Journal (2016) • ISSN 1752-6981 C 2014 John Wiley & Sons Ltd V
Vannucci et al. inflammatory nodule Solitary phrenic
Solitary phrenic inflammatory nodule Vannucci et al.
Figure 1. Standard chest X-ray at diagnosis (left side) and at 3.5 years follow-up (right side).
belonging to peripheral neuronal paths. Therefore, workup was deepened to exclude systemic conditions. Immunoserology, autoimmunitary tests and infectious disease specific analysis were completely negative and ruled out any possible latent infection or subclinical rheumatic syndromes. The patient underwent respiratory function tests: mild obstructive respiratory impairment, normal emogasanalysis. In the multidisciplinary ward round, surgical intervention was chosen deeming probable the neoplastic aetiology of the diaphragmatic relaxation. Through a small right posterolateral thoracotomy, a small solid whitish nodule of the phrenic nerve was found. The lesion was situated at the anterior margin of the superior vena cava with no infiltrating feature. The tumour was excised by segmental phrenic nerve removal, and the normal chest cavity volume was restored by diaphragmatic plication. Posterolateral thoracotomy gave a good exposure of the lateral mediastinum, and the primary lesion was easily found and resected. At the same time, diaphragmatic manipulation was favoured by this incision. Normal lung deflation and free pleural space often allows to reduce incision’s length. At thoracotomy the phrenic nodule appeared to completely involve the nerve in its circum-
ference with no cleavage. Biopsy for frozen section was thus avoided for the following reasons: (i) impossibility to have a representative tissue sample without nerve damage; (ii) high probability of neural tumour (indication to have the mass removed at once avoiding morcellation); (iii) indication to segmental phrenic nerve resection considering the pre-existing diaphragm impairment; and (iv) proper tissue quantity for final surgical pathology assessment. Macroscopically, the specimen consisted of a 3-cm segment of nerve with a swelling of 0.7 × 0.5 cm (Fig. 2B). The tissue samples were fixed in 10% buffered formalin and embedded in paraffin. The 4-μm tissue sections were stained with haematoxylin and eosin. Immunostains for CD3 [Novocastra/Leica (Buffalo Groove, IL, USA), clone PS1, ready to use], CD20 (Novocastra/Leica, clone L26, ready to use) and CD34 (Novocastra/Leica, clone QBEnd/10, ready to use) were performed on selected sections. There were present, microscopically, oedema and many perivascular inflammatory infiltrations of endoneurial vessels in absence of mural fibrinoid necrosis and karyorrhexis (possible cause of PET negativity, Fig. 3A-B). The infiltrations were constituted of a mixed inflammatory cell population consisting of lymphocytes T (CD3
Figure 2. (A) Computed tomography (CT) scan of thorax and abdomen revealed a little nodular mass along the course of the right phrenic nerve, imprinting the anterior edge of superior vena cava. (B) Surgical specimen: nodular, solid, not capsulated lesion of the phrenic nerve.
The 2 Clinical Respiratory Journal (2016) • ISSN 1752-6981 C 2014 John Wiley & Sons Ltd V
401 The Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
Vannucci et al. inflammatory nodule Solitary phrenic
Solitary phrenic inflammatory nodule Vannucci et al.
Figure 3. (A) Low-power view showing a large number of perivascular inflammatory infiltrate [haematoxylin/eosin (EE) 40×]. (B) High-power view showing endoneurial vessels surrounded by lymphoplasmacytic infiltrate (EE and CD34 200×). Immunostain for CD 3 (C) and CD20 (D) shows that the perivascular inflammatory infiltrate was mainly consisting of lymphocytes T and B (200×).
expression) (Fig. 3C), B (CD20 expression) (Fig. 3D) and plasma cells. Hospital discharge occurred in day 6 after a smooth postoperative course. Two years later, the patient was controlled by chest X-ray and physical examination. The most recent chest X-ray (3.5 years follow-up, Fig. 1 – right side) shows a mild asymmetry between hemidiaphragms; this asymmetry appears to be consistent to long-term progressive flaccidity after denervation. No episodes of acute dyspnoea are reported up to date during follow-up after surgery. His condition is currently excellent. He has completely come back to normal life, full-time work and all prior activities. Subjective report of postoperative respiratory improvement was considered a sufficiently adequate descriptor by caring physician, and no functional respiratory test was thus performed after surgery.
Discussion Diaphragmatic paralysis can be caused by traumas, systemic disorders, neurological diseases, iatrogenic injury (surgery of chest and neck) and neoplastic compression/infiltration of the nerve. Phrenic nerve palsy can also be because of infectious processes (3, 4). Primitive tumour of the phrenic nerve are mostly diagnosed when a bulky disease produces compression of other mediastinal organs, while diaphragmatic dysfunction is rarely related to such neoplasms especially if they are small masses, although it is The 402Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
occasionally described in case of neurilemmoma and neurofibroma (5). The above-mentioned tumours are rare, and differential diagnosis with other neoplasms of the mediastinum involving the phrenic nerve can be difficult and often clarified only by histology (6). Infectious diseases affecting the phrenic nerve are exceptional events, and the diagnosis is sometimes obtained after a long time and ‘ex adiuvantibus’. Moreover, in a consistent number of cases, the diagnosis remains unknown especially in old patients with heavy comorbidities. Benign disorders affecting the phrenic nerve encompass Guillain-Barrè and Charcot-MarieTooth syndromes. Moreover several other peripheral neuropathies have been related to phrenic impairment but nodular isolated findings never correspond to these diagnosis (7). When a mediastinal mass is encountered, the occurrence of a small, roundish mass, slightly lateral and anatomically located on the course of the nerve, the suspicion of a phrenic nerve tumour is reasonable considering the spectrum of possibility (8). After undergoing CT scan, some imaging details and clinical features can be of help to identify the mass; the relationship between the mass and the nerve is the main attribute to be investigated. First of all, the mass can be eccentric or concentric; in case of eccentricity, the tumour is probable coming up from neuroglial cells, while concentric lesions mostly arise from neurons. Diffuse inflammatory reactions should show a concentric shape, but a sure diagnosis based on 3 The Clinical Respiratory Journal (2016) • ISSN 1752-6981 C 2014 John Wiley & Sons Ltd V
Vannucciphrenic et al. inflammatory nodule Solitary
imaging is impossible for the ruling out of a malignancy. The surgical biopsy is the only reliable technique for obtaining the definite diagnosis and therapy of that kind of single nodular lesion of the mediastinum. To the best of our knowledge, such a kind of phrenic nerve neuritis presented as a nodular mediastinal lesion has never been described before. The recent issue of the Thoracic Surgery Clinics (2) regarding the surgery of the diaphragm provides an updated collection of possible causes of unilateral phrenic palsy. In the synthetic table, all the possible reasons are listed, but any kind of ‘localised plasmacellular diffuse neuritis’ is missing and, for this reason, we have submitted this brief description.
Conclusion The occurrence of an isolated phrenic nerve nodule in a serum-negative patient can be an idiopathic inflammatory nodule even if it is really improbable. Surgery is the only invasive method to achieve a fine diagnosis in such a setting. Given the clinical and pathological facts, the aetiology remains undisclosed but treatment has been effective.
The Clinical Respiratory Journal (2016) • ISSN 1752-6981 4 C 2014 John Wiley & Sons Ltd V
Solitary phrenic inflammatory nodule Vannucci et al.
References 1. Moinuddeen K, Baltzer JW, Zama N. Diaphragmatic eventration: an uncommon presentation of a phrenic nerve schwannoma. Chest. 2001;119: 1615–6. 2. Ko AM, Darling GE. Acquired paralysis of the diaphragm. In: Darling G, Ferguson MK, editors. Thoracic Surgery Clinics. Philadelphia, Saunders-Elsevier, 2009: 501–10. 3. Oike M, Naito T, Tsukada M, et al. A case of diaphragmatic paralysis complicated by herpes zoster virus infection. Intern Med. 2012;51: 1259–63. 4. Odell JA, Kennelly K, Stauffer J. Phrenic nerve palsy and Parsonage -Turner syndrome. Ann Thorac Surg. 2011;92: 349–51. 5. Mevio E, Gorini E, Sbrocca M, et al. Unusual cases of cervical nerve schwannomas: phrenic and vagus nerve involvement. Auris Nasus Larynx. 2003;30: 209–13. 6. Smahi M, Lakaranbi M, Ouadnouni Y, et al. Intrathoracic phrenic nerve neurofibroma. Ann Thorac Surg. 2011;91: 57–8. 7. Burakgazi AZ, Höke A. Respiratory muscle weakness in peripheral neuropathies. J Peripher Nerv Syst. 2010;15(4): 307–13. 8. Le Pimpec-Barthes F, Martinod E, Riquet M, SaintBlancard P, Jancovici R. Tumors of the phrenic nerve. Rev Mal Respir. 1998;15: 93–5.
403 The Clinical Respiratory Journal (2014) • ISSN 1752-6981 © 2014 John Wiley & Sons Ltd
