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Subtotal and total resection of superficial plexiform neurofibromas of face and neck: four case reports
ARTICLE IN PRESS Journal of Cranio-Maxillofacial Surgery (2005) 33, 55–60 r 2004 European Association for Cranio-Maxillofacial Surgery doi:10.1016/j.jcms.2004.08.004, available online at http://www.sciencedirect.com
Subtotal and total resection of superficial plexiform neurofibromas of face and neck: four case reports Reinhard E. FRIEDRICH1, Rainer SCHMELZLE1, Melanie HARTMANN1, Victor-F. MAUTNER2 1
Department of Maxillofacial Surgery, University Hospital Hamburg-Eppendorf (Head: Prof. Dr. Dr. Rainer Schmelzle); 2Department of Neurology (Head: Dr. Gottesleben), Klinikum Nord Ochsenzoll, Hamburg, Germany
SUMMARY. Introduction: Plexiform neurofibromas are benign tumours of the peripheral nerves and connective tissue. They develop most often in patients with neurofibromatosis type 1 (NF1) and often grow continuously. Removal of plexiform neurofibromas is usually unsatisfactory because the network-like growth of these tumours often involves multiple nerve fascicles and other adjacent tissues. It has been previously shown that magnetic resonance tomography can distinguish the growth patterns of plexiform neurofibromas into three different categories: superficial, displacing and invasive. Patients and methods: Three cases are described with successful subtotal resections of superficial plexiform neurofibromas, and one case with total resection following the diagnosis of tumour subtype using magnetic resonance imaging (MRI). Results: There was a significant, lasting improvement in appearance which demonstrates that surgical intervention in the case of superficial plexiform neurofibroma is valuable. Conclusion: Careful classification of plexiform neurofibroma by means of MRI provides valuable information for the surgical management of patients. It enables the distinction to be drawn between this subtype and the other two subtypes of plexiform neurofibromas. r 2004 European Association for Cranio-Maxillofacial Surgery
Keywords: Neurofibromatosis type 1; Plexiform neurofibromas; Tumour resection; Growth pattern
from subcutaneous or cutaneous nerves and may remain within the upper skin layers – usually not involving major nerves. For these total or subtotal resection may be possible. In contrast, invasive PNF infiltrate multiple tissue planes and cannot be completely resected without functional disturbance. In this report, subtotal and total resections of superficial PNF in four NF1 patients are described.
INTRODUCTION Plexiform neurofibromas (PNF) are benign tumours originating from subcutaneous or visceral peripheral nerves and involve multiple fascicles. These tumours are either present at birth or develop within the first years of life. Plexiform neurofibromas occur almost exclusively in patients with neurofibromatosis type 1 (NF1), an autosomal dominant disorder caused by genetic alterations of the tumour suppressor gene, NF1 (Huson, 1989). PNF can arise in various parts of the body, e.g., as anterior mediastinal masses, sciatic nerve lesions with pelvic extension, or perirectal plexiform and uterine tumours, all leading to severe clinical sequelae (Tonsgard et al., 1996). Tumours occurring in the head and neck often lead to facial disfigurement, pain and functional deficits, and thus require surgical intervention. However, due to the large size and involvement of multiple fascicles of nerves as well as multiple tissue layers, satisfactory resection is often not possible without functional deficits resulting (Artico et al., 1997; Packer et al., 2002). Tumour rests may re-grow after the operation. The growth rates and patterns of PNF vary largely and are not predictable. Previously it has been demonstrated that magnetic resonance imaging (MRI) enables distinction between 3 growth patterns in PNF: superficial, displacing and invasive (Friedrich et al., 2003). Superficial PNF arise
PATIENTS AND METHODS The four patients described in this study were examined in the NF-clinic in Hamburg. Diagnosis of NF1 was based on the updated National Institute of Health criteria for neurofibromatoses (Gutmann et al., 1997). All patients were examined dermatologically, neurologically and ophthalmologically as well as by ultrasound of the abdominal organs. PNF diagnosis was made on the following basis: subcutaneous location by palpation (as a ‘‘sack of worms’’) associated with thickening of the skin, local hypertrophy, excess hair growth, hyperpigmentation, and a past medical history of prepubertal onset of symptoms. MRI was undertaken covering the tumour regions. Tumour regrowth was monitored for 2–6 years postoperatively. MRI was performed with 1.5 T using T1 and T2 weighted sequences including a short-tau inversion-recovery (STIR) sequence. Ultra 55
ARTICLE IN PRESS 56 Journal of Cranio-Maxillofacial Surgery
rapid half Fourier single-shot turbo spin-echo (HASTE) sequences were used for imaging the trunk (Mautner et al., 2003). Intravenous contrast medium (gadolinium) was given to all patients to enhance tumour/tissue contrast. These techniques improve the identification of plexiform neurofibromas in NF1 (Mautner et al., 2003). CASE REPORTS Case 1 In 1997, a 69 year-old male patient was referred with a ‘‘lumpy’’ tumour hindering right upper eye lid mobility since 1990. This patient had a PNF of the right forehead and had already undergone an operation at the age of 20. A scar following the former right frontal hair line suggested a modified frontal face lift approach. The patient noticed a complete loss of frontal skin mobility since that operation, probably due to damage of the frontal
branch of the facial nerve. Over the years, the patient had experienced progressive ptosis of the right eyebrow and upper eye lid, extending to the skin covering the temporal fossa and associated with a reduced visual field. In 1997, 49 years after the first operation, the old incision was re-opened to mobilize the fronto-temporal skin (Fig. 1). During the operation and excision of a strip of skin 2 cm wide it became obvious that the connective tissue was extremely loosely attached to the periosteum and consisted of a gelatine-like layer. This was excised and histological analysis revealed a diffusely distributed neurofibroma in the entire right fronto-temporal region. Healing was uneventful. Two months later, a second operation was carried out to correct the ptosis with excision of tumour-invaded frontal skin above the right eyebrow and of the excessively folded upper eyelid skin. Again, healing was uneventful and the visual field improved. Subtotal resection of the tumour was thus achieved with functional improvement. No regrowth was found by means of MRI 6 years after the operation (Fig. 1).
Fig. 1 – (A) A 69-year-old patient with a tumour of the right temple, (B) preoperative MRI depicting superficial infiltration of the right temporal fossa without bone involvement (arrow: tumour region), (C) postoperative view with patient reclining, (D) MRI 4 years after the operation showing small superficial tumour rests in the right temporal fossa (arrow: tumour region).
ARTICLE IN PRESS Resection of superficial plexiform neurofibromas in NFI 57
Case 2 In 2001, a 24-year-old male attended with a tumour mass extending from the right lower cheek to the ipsilateral clavicular region. The skin of this area was hyperpigmented and the tumour was located in the region of the third branch of the trigeminal nerve. There was some hypertrichosis. MRI confirmed the diagnosis of PNF and revealed superficial growth (Fig. 2). As a first step, a debulking of the tumour was carried out via a submandibular approach, thereby situating the scar within the hyperpigmented area. The visible tumour was of greyish colour and of a gelatine-like consistency, starting immediately below a small layer of subepidermal fat and did not extend deep to the platysma, sternocleidomastoid or masseter muscles, as was expected from the MRI (Fig. 2B). The solid tumour layer was heavily vascularized. Within minutes of the incision, the complete region swelled markedly with the skin at the incisional
margins distending. After excision of the bulky skin, a Redon drain was inserted and the wound was closed without tension. This was repeated three times to reduce the tumour step-by-step and resulted in an improved facial appearance. Despite careful drainage the wound had to be revised 1 day after ablative surgery due to prolonged bleeding after two of the three debulking procedures. After removing the haematoma, no bleeding source was found. The tumour was shown microscopically to be PNF. No regrowth was detected after 1-year’s follow-up (Fig. 2). Case 3 A 14-year-old boy with NF1 had a hyperpigmented skin area (approximately 4 4 cm2) covering the laryngeal prominence. MRI revealed superficial growth of the tumour. This tumour was completely excised and the defect closed primarily. The excised
Fig. 2 – (A) A 24-year-old male patient with a tumour of the right cheek stretching to the neck, (B) preoperative MRI depicting large confluent superficial tumour mass adjacent to the parotid gland and lateral neck muscles without infiltrating the muscles (arrow: tumour region), (C) postoperative view, (D) MRI 1 year after the operation showing small subcutaneous tumour rests adjacent to the mandibular ramus and the floor of the mouth (arrow: tumour region).
ARTICLE IN PRESS 58 Journal of Cranio-Maxillofacial Surgery
Fig. 3 – (A) A 14-year-old boy with a small superficial tumour covering the laryngeal prominence, (B) preoperative MRI, (C) postoperative view, (D) no evidence of residual tumour 3.5 years after the operation on MRI (arrows: tumour region).
tissue proved to be a diffuse PNF. No local recurrence was found 2 years after the operation (Fig. 3). Case 4 The 46-year-old male had a ‘‘lumpy’’ tumour mass of the left submandibular region and a disfigured left ear lobe. The neurofibroma had been diagnosed as a superficial type according to the MRI. The debulking of the diffuse, superficial PNF was performed in a similar manner to case 1. Healing was uneventful. No local recurrence was noticed 2 years after the subtotal resection (Fig. 4).
DISCUSSION Surgical intervention is presently the only treatment option for PNF. However, total resection of the tumour is usually not possible, and in many cases, surgical intervention can only reduce tumour mass. Factors such as patient’s age, extent and location of the tumour have been discussed to correlate with
surgical outcomes and postoperative tumour regrowth (Jackson et al., 1993; Needle et al., 1997). For example, the poor outcome of surgical therapy in many cases of orbital neurofibromatosis (Henderson, 1980) can be – at least in part – attributed to the prevalence of diffuse and infiltrating plexiform neurofibromas in this region. In fact, orbital dysplasia can occur with and without PNF in NF1 (Riccardi, 1992). PNFs of this subtype are incompletely removed in every surgical attempt that saves the orbital muscles or the eye itself (Henderson 1980; Jackson et al., 1983, 1993; Angel et al., 1994). Hitherto, the subtyping of PNF has not been applied to study the efficacy of surgery in NF1. Recently, it was reported that PNF can be categorized into three types based on MRI findings according to their growth patterns. The authors discussed the options of resecting superficial PNF according to these patterns (Friedrich et al., 2003). In the present paper, it is demonstrated that subtotal to total resection of superficial PNF is possible without post-surgical neurological and functional deficit. Large tumours can at least be debulked successfully, sometimes in several steps, significantly lessening disfigurement of the patients. In one case, total resection of the PNF
ARTICLE IN PRESS Resection of superficial plexiform neurofibromas in NFI 59
Fig. 4 – (A) A 46-year-old male patient with a tumour behind the left ear, (B) MRI depicting a retro- and infra-auricular PNF without infiltration of deeper layers, (C) postoperative view, (D) MRI showing small residual tumour with thickening of cutis and subcutis in the region of the left mandibular angle without infiltrating deeper tissues, 1 year postoperatively (arrows: tumour region).
was achieved. This was possible due to the small size of the tumour and the location, allowing resection without functional impairment. The results demonstrate the advantage of early surgical intervention for superficial PNF. So far no regrowth of the tumours has been found 2–5 years postoperatively. However, these patients will be monitored for a longer period. The previous MRI study showed that the surgical outcome for PNF largely depends on the growth type of the tumours (Friedrich et al., 2003). Thus classification of neurofibromas by means of MRI is a valuable tool for surgical treatment planning. Depending on their sizes and sites, some superficial PNF may even be curatively resected. The satisfactory results may encourage surgical interventions for superficial PNF, which are likely to lead to improvement in appearances and fewer clinical deficits, thus increasing the quality of life for these patients.
CONCLUSION This study shows favourable results from debulking procedures for plexiform neurofibromas in neurofi-
bromatosis type 1 of the head and neck region. One reason for this successful surgery for plexiform neurofibroma is the selection of patients according to an MRI-based subtyping of these tumours. ACKNOWLEDGEMENT
We thank Dr. L. Kluwe for her support preparing this manuscript. This study was supported by Deutsche Krebshilfe, project No. 70-3072-Ma4. References Angel MF, Persing JA, Edgerton MT: Reconstructive surgery for neurofibromatosis. in: The Neurofibromatoses. A Pathogenetic and Clinical Overview. Chapman & Hall, London, pp. 331–354, 1994 Artico M, Cervoni L, Wierzbicki V, D’Andrea V, Nucci F: Benign neural sheath tumours of major nerves: characteristics in 119 surgical cases. Acta Neurochir (Wien) 139: 1108–1116, 1997 Friedrich RE, Korf B, Fu¨nsterer C, Mautner VF: Growth type of plexiform neurofibromas in NF1 determined on magnetic resonance images. Anticancer Res 23: 949–952, 2003 Gutmann DH, Aylsworth A, Carey JC, Korf B, Marks J, Pyeritz RE, Rubenstein A, Viskochil D: The diagnostic evaluation and
ARTICLE IN PRESS 60 Journal of Cranio-Maxillofacial Surgery multidisciplinary management of neurofibromatosis 1 and neurofibromatosis 2. J Am Med Assoc 278: 51–57, 1997 Henderson JW: Orbital Tumors, 2nd edition. Thieme, StuttgartNew York, 1980 Huson SM: Recent developments in the diagnosis and management of neurofibromatosis. Arch Dis Child 64: 745–749, 1989 Jackson IT, Carbonnel A, Potparic Z, Shaw K: Orbitotemporal neurofibromatosis: classification and treatment. Plast Reconstr Surg 92: 1–11, 1993 Jackson IT, Laws Jr. ER, Martin RD: The surgical management of orbital neurofibromatosis. Plast Reconstr Surg 71: 751–758, 1983 Mautner VF, Friedrich RE, von Deimling A, Hagel C, Korf B, Kno¨fel MT, Wenzel R, Fu¨nsterer C: Malignant peripheral nerve sheath tumours in neurofibromatosis type 1: MRI supports the diagnosis of malignant plexiform neurofibroma. Neuroradiology 45: 618–625, 2003 Needle MN, Cnaan A, Dattilo J, Chatten J, Phillips PC, Shochat S, Sutton LN, Vaughan SN, Zackai EH, Zhao H, Molloy PT: Prognostic signs in the surgical management of plexiform neurofibroma: the Children’s Hospital of Philadelphia experience, 1974–1994. J Pediatr 131: 678–682, 1997 Packer RJ, Gutmann DH, Rubenstein A, Viskochil D, Zimmerman RA, Vezina G, Small J, Korf B: Plexiform
neurofibromas in NF1: toward biologic-based therapy. Neurology 58: 1461–1470, 2002 Riccardi, VM: Neurofibromatosis. Phenotype, Natural History, and Pathogenesis. Baltimore, London: The Johns Hopkins University Press, 343–345, 1992 Tonsgard JH, Kwak SM, Short MP, Dachman AH: CT imaging in adults with neurofibromatosis 1: frequent asymptomatic plexiform lesions. Neurology 50: 1755–1760, 1996 Prof. Dr. Dr. Reinhard E. FRIEDRICH, MD, DMD Department of Maxillofacial Surgery (Nordwestdeutsche Kieferklinik) University Hospital Eppendorf Martinistr. 52, 20246 Hamburg Germany Tel.: 49 40 42803 6039 Fax: 49 40 42803 8120 E-mail: [email protected] Paper received 2 December 2003 Accepted 12 August 2004
Subtotal and total resection of superficial plexiform neurofibromas of face and neck: four case reports Reinhard E. FRIEDRICH1, Rainer SCHMELZLE1, Melanie HARTMANN1, Victor-F. MAUTNER2 1
Department of Maxillofacial Surgery, University Hospital Hamburg-Eppendorf (Head: Prof. Dr. Dr. Rainer Schmelzle); 2Department of Neurology (Head: Dr. Gottesleben), Klinikum Nord Ochsenzoll, Hamburg, Germany
SUMMARY. Introduction: Plexiform neurofibromas are benign tumours of the peripheral nerves and connective tissue. They develop most often in patients with neurofibromatosis type 1 (NF1) and often grow continuously. Removal of plexiform neurofibromas is usually unsatisfactory because the network-like growth of these tumours often involves multiple nerve fascicles and other adjacent tissues. It has been previously shown that magnetic resonance tomography can distinguish the growth patterns of plexiform neurofibromas into three different categories: superficial, displacing and invasive. Patients and methods: Three cases are described with successful subtotal resections of superficial plexiform neurofibromas, and one case with total resection following the diagnosis of tumour subtype using magnetic resonance imaging (MRI). Results: There was a significant, lasting improvement in appearance which demonstrates that surgical intervention in the case of superficial plexiform neurofibroma is valuable. Conclusion: Careful classification of plexiform neurofibroma by means of MRI provides valuable information for the surgical management of patients. It enables the distinction to be drawn between this subtype and the other two subtypes of plexiform neurofibromas. r 2004 European Association for Cranio-Maxillofacial Surgery
Keywords: Neurofibromatosis type 1; Plexiform neurofibromas; Tumour resection; Growth pattern
from subcutaneous or cutaneous nerves and may remain within the upper skin layers – usually not involving major nerves. For these total or subtotal resection may be possible. In contrast, invasive PNF infiltrate multiple tissue planes and cannot be completely resected without functional disturbance. In this report, subtotal and total resections of superficial PNF in four NF1 patients are described.
INTRODUCTION Plexiform neurofibromas (PNF) are benign tumours originating from subcutaneous or visceral peripheral nerves and involve multiple fascicles. These tumours are either present at birth or develop within the first years of life. Plexiform neurofibromas occur almost exclusively in patients with neurofibromatosis type 1 (NF1), an autosomal dominant disorder caused by genetic alterations of the tumour suppressor gene, NF1 (Huson, 1989). PNF can arise in various parts of the body, e.g., as anterior mediastinal masses, sciatic nerve lesions with pelvic extension, or perirectal plexiform and uterine tumours, all leading to severe clinical sequelae (Tonsgard et al., 1996). Tumours occurring in the head and neck often lead to facial disfigurement, pain and functional deficits, and thus require surgical intervention. However, due to the large size and involvement of multiple fascicles of nerves as well as multiple tissue layers, satisfactory resection is often not possible without functional deficits resulting (Artico et al., 1997; Packer et al., 2002). Tumour rests may re-grow after the operation. The growth rates and patterns of PNF vary largely and are not predictable. Previously it has been demonstrated that magnetic resonance imaging (MRI) enables distinction between 3 growth patterns in PNF: superficial, displacing and invasive (Friedrich et al., 2003). Superficial PNF arise
PATIENTS AND METHODS The four patients described in this study were examined in the NF-clinic in Hamburg. Diagnosis of NF1 was based on the updated National Institute of Health criteria for neurofibromatoses (Gutmann et al., 1997). All patients were examined dermatologically, neurologically and ophthalmologically as well as by ultrasound of the abdominal organs. PNF diagnosis was made on the following basis: subcutaneous location by palpation (as a ‘‘sack of worms’’) associated with thickening of the skin, local hypertrophy, excess hair growth, hyperpigmentation, and a past medical history of prepubertal onset of symptoms. MRI was undertaken covering the tumour regions. Tumour regrowth was monitored for 2–6 years postoperatively. MRI was performed with 1.5 T using T1 and T2 weighted sequences including a short-tau inversion-recovery (STIR) sequence. Ultra 55
ARTICLE IN PRESS 56 Journal of Cranio-Maxillofacial Surgery
rapid half Fourier single-shot turbo spin-echo (HASTE) sequences were used for imaging the trunk (Mautner et al., 2003). Intravenous contrast medium (gadolinium) was given to all patients to enhance tumour/tissue contrast. These techniques improve the identification of plexiform neurofibromas in NF1 (Mautner et al., 2003). CASE REPORTS Case 1 In 1997, a 69 year-old male patient was referred with a ‘‘lumpy’’ tumour hindering right upper eye lid mobility since 1990. This patient had a PNF of the right forehead and had already undergone an operation at the age of 20. A scar following the former right frontal hair line suggested a modified frontal face lift approach. The patient noticed a complete loss of frontal skin mobility since that operation, probably due to damage of the frontal
branch of the facial nerve. Over the years, the patient had experienced progressive ptosis of the right eyebrow and upper eye lid, extending to the skin covering the temporal fossa and associated with a reduced visual field. In 1997, 49 years after the first operation, the old incision was re-opened to mobilize the fronto-temporal skin (Fig. 1). During the operation and excision of a strip of skin 2 cm wide it became obvious that the connective tissue was extremely loosely attached to the periosteum and consisted of a gelatine-like layer. This was excised and histological analysis revealed a diffusely distributed neurofibroma in the entire right fronto-temporal region. Healing was uneventful. Two months later, a second operation was carried out to correct the ptosis with excision of tumour-invaded frontal skin above the right eyebrow and of the excessively folded upper eyelid skin. Again, healing was uneventful and the visual field improved. Subtotal resection of the tumour was thus achieved with functional improvement. No regrowth was found by means of MRI 6 years after the operation (Fig. 1).
Fig. 1 – (A) A 69-year-old patient with a tumour of the right temple, (B) preoperative MRI depicting superficial infiltration of the right temporal fossa without bone involvement (arrow: tumour region), (C) postoperative view with patient reclining, (D) MRI 4 years after the operation showing small superficial tumour rests in the right temporal fossa (arrow: tumour region).
ARTICLE IN PRESS Resection of superficial plexiform neurofibromas in NFI 57
Case 2 In 2001, a 24-year-old male attended with a tumour mass extending from the right lower cheek to the ipsilateral clavicular region. The skin of this area was hyperpigmented and the tumour was located in the region of the third branch of the trigeminal nerve. There was some hypertrichosis. MRI confirmed the diagnosis of PNF and revealed superficial growth (Fig. 2). As a first step, a debulking of the tumour was carried out via a submandibular approach, thereby situating the scar within the hyperpigmented area. The visible tumour was of greyish colour and of a gelatine-like consistency, starting immediately below a small layer of subepidermal fat and did not extend deep to the platysma, sternocleidomastoid or masseter muscles, as was expected from the MRI (Fig. 2B). The solid tumour layer was heavily vascularized. Within minutes of the incision, the complete region swelled markedly with the skin at the incisional
margins distending. After excision of the bulky skin, a Redon drain was inserted and the wound was closed without tension. This was repeated three times to reduce the tumour step-by-step and resulted in an improved facial appearance. Despite careful drainage the wound had to be revised 1 day after ablative surgery due to prolonged bleeding after two of the three debulking procedures. After removing the haematoma, no bleeding source was found. The tumour was shown microscopically to be PNF. No regrowth was detected after 1-year’s follow-up (Fig. 2). Case 3 A 14-year-old boy with NF1 had a hyperpigmented skin area (approximately 4 4 cm2) covering the laryngeal prominence. MRI revealed superficial growth of the tumour. This tumour was completely excised and the defect closed primarily. The excised
Fig. 2 – (A) A 24-year-old male patient with a tumour of the right cheek stretching to the neck, (B) preoperative MRI depicting large confluent superficial tumour mass adjacent to the parotid gland and lateral neck muscles without infiltrating the muscles (arrow: tumour region), (C) postoperative view, (D) MRI 1 year after the operation showing small subcutaneous tumour rests adjacent to the mandibular ramus and the floor of the mouth (arrow: tumour region).
ARTICLE IN PRESS 58 Journal of Cranio-Maxillofacial Surgery
Fig. 3 – (A) A 14-year-old boy with a small superficial tumour covering the laryngeal prominence, (B) preoperative MRI, (C) postoperative view, (D) no evidence of residual tumour 3.5 years after the operation on MRI (arrows: tumour region).
tissue proved to be a diffuse PNF. No local recurrence was found 2 years after the operation (Fig. 3). Case 4 The 46-year-old male had a ‘‘lumpy’’ tumour mass of the left submandibular region and a disfigured left ear lobe. The neurofibroma had been diagnosed as a superficial type according to the MRI. The debulking of the diffuse, superficial PNF was performed in a similar manner to case 1. Healing was uneventful. No local recurrence was noticed 2 years after the subtotal resection (Fig. 4).
DISCUSSION Surgical intervention is presently the only treatment option for PNF. However, total resection of the tumour is usually not possible, and in many cases, surgical intervention can only reduce tumour mass. Factors such as patient’s age, extent and location of the tumour have been discussed to correlate with
surgical outcomes and postoperative tumour regrowth (Jackson et al., 1993; Needle et al., 1997). For example, the poor outcome of surgical therapy in many cases of orbital neurofibromatosis (Henderson, 1980) can be – at least in part – attributed to the prevalence of diffuse and infiltrating plexiform neurofibromas in this region. In fact, orbital dysplasia can occur with and without PNF in NF1 (Riccardi, 1992). PNFs of this subtype are incompletely removed in every surgical attempt that saves the orbital muscles or the eye itself (Henderson 1980; Jackson et al., 1983, 1993; Angel et al., 1994). Hitherto, the subtyping of PNF has not been applied to study the efficacy of surgery in NF1. Recently, it was reported that PNF can be categorized into three types based on MRI findings according to their growth patterns. The authors discussed the options of resecting superficial PNF according to these patterns (Friedrich et al., 2003). In the present paper, it is demonstrated that subtotal to total resection of superficial PNF is possible without post-surgical neurological and functional deficit. Large tumours can at least be debulked successfully, sometimes in several steps, significantly lessening disfigurement of the patients. In one case, total resection of the PNF
ARTICLE IN PRESS Resection of superficial plexiform neurofibromas in NFI 59
Fig. 4 – (A) A 46-year-old male patient with a tumour behind the left ear, (B) MRI depicting a retro- and infra-auricular PNF without infiltration of deeper layers, (C) postoperative view, (D) MRI showing small residual tumour with thickening of cutis and subcutis in the region of the left mandibular angle without infiltrating deeper tissues, 1 year postoperatively (arrows: tumour region).
was achieved. This was possible due to the small size of the tumour and the location, allowing resection without functional impairment. The results demonstrate the advantage of early surgical intervention for superficial PNF. So far no regrowth of the tumours has been found 2–5 years postoperatively. However, these patients will be monitored for a longer period. The previous MRI study showed that the surgical outcome for PNF largely depends on the growth type of the tumours (Friedrich et al., 2003). Thus classification of neurofibromas by means of MRI is a valuable tool for surgical treatment planning. Depending on their sizes and sites, some superficial PNF may even be curatively resected. The satisfactory results may encourage surgical interventions for superficial PNF, which are likely to lead to improvement in appearances and fewer clinical deficits, thus increasing the quality of life for these patients.
CONCLUSION This study shows favourable results from debulking procedures for plexiform neurofibromas in neurofi-
bromatosis type 1 of the head and neck region. One reason for this successful surgery for plexiform neurofibroma is the selection of patients according to an MRI-based subtyping of these tumours. ACKNOWLEDGEMENT
We thank Dr. L. Kluwe for her support preparing this manuscript. This study was supported by Deutsche Krebshilfe, project No. 70-3072-Ma4. References Angel MF, Persing JA, Edgerton MT: Reconstructive surgery for neurofibromatosis. in: The Neurofibromatoses. A Pathogenetic and Clinical Overview. Chapman & Hall, London, pp. 331–354, 1994 Artico M, Cervoni L, Wierzbicki V, D’Andrea V, Nucci F: Benign neural sheath tumours of major nerves: characteristics in 119 surgical cases. Acta Neurochir (Wien) 139: 1108–1116, 1997 Friedrich RE, Korf B, Fu¨nsterer C, Mautner VF: Growth type of plexiform neurofibromas in NF1 determined on magnetic resonance images. Anticancer Res 23: 949–952, 2003 Gutmann DH, Aylsworth A, Carey JC, Korf B, Marks J, Pyeritz RE, Rubenstein A, Viskochil D: The diagnostic evaluation and
ARTICLE IN PRESS 60 Journal of Cranio-Maxillofacial Surgery multidisciplinary management of neurofibromatosis 1 and neurofibromatosis 2. J Am Med Assoc 278: 51–57, 1997 Henderson JW: Orbital Tumors, 2nd edition. Thieme, StuttgartNew York, 1980 Huson SM: Recent developments in the diagnosis and management of neurofibromatosis. Arch Dis Child 64: 745–749, 1989 Jackson IT, Carbonnel A, Potparic Z, Shaw K: Orbitotemporal neurofibromatosis: classification and treatment. Plast Reconstr Surg 92: 1–11, 1993 Jackson IT, Laws Jr. ER, Martin RD: The surgical management of orbital neurofibromatosis. Plast Reconstr Surg 71: 751–758, 1983 Mautner VF, Friedrich RE, von Deimling A, Hagel C, Korf B, Kno¨fel MT, Wenzel R, Fu¨nsterer C: Malignant peripheral nerve sheath tumours in neurofibromatosis type 1: MRI supports the diagnosis of malignant plexiform neurofibroma. Neuroradiology 45: 618–625, 2003 Needle MN, Cnaan A, Dattilo J, Chatten J, Phillips PC, Shochat S, Sutton LN, Vaughan SN, Zackai EH, Zhao H, Molloy PT: Prognostic signs in the surgical management of plexiform neurofibroma: the Children’s Hospital of Philadelphia experience, 1974–1994. J Pediatr 131: 678–682, 1997 Packer RJ, Gutmann DH, Rubenstein A, Viskochil D, Zimmerman RA, Vezina G, Small J, Korf B: Plexiform
neurofibromas in NF1: toward biologic-based therapy. Neurology 58: 1461–1470, 2002 Riccardi, VM: Neurofibromatosis. Phenotype, Natural History, and Pathogenesis. Baltimore, London: The Johns Hopkins University Press, 343–345, 1992 Tonsgard JH, Kwak SM, Short MP, Dachman AH: CT imaging in adults with neurofibromatosis 1: frequent asymptomatic plexiform lesions. Neurology 50: 1755–1760, 1996 Prof. Dr. Dr. Reinhard E. FRIEDRICH, MD, DMD Department of Maxillofacial Surgery (Nordwestdeutsche Kieferklinik) University Hospital Eppendorf Martinistr. 52, 20246 Hamburg Germany Tel.: 49 40 42803 6039 Fax: 49 40 42803 8120 E-mail: [email protected] Paper received 2 December 2003 Accepted 12 August 2004