February 26, 2014
11:05:34am
WSPC/135-HS
FA1
1472002
Hand Surgery, Vol. 19, No. 1 (2014) 95–97 © World Scientific Publishing Company DOI: 10.1142/S0218810414720022
MALIGNANT SCHWANNOMA OF THE RADIAL NERVE WITH UNUSUAL PRESENTATION: A CASE REPORT Yu Chung Wong,* Pak Cheong Ho,* Wing Lim Tse,* Louis Tsun Cheung Chow† and Clara Wing Yee Wong* *Department
Hand Surg. 2014.19:95-97. Downloaded from www.worldscientific.com by MCGILL UNIVERSITY on 02/04/15. For personal use only.
†Department
of Orthopaedics and Traumatology
of Anatomical and Cellular Pathology Prince of Wales Hospital Hong Kong, China
Received 25 May 2013; Revised 21 July 2013; Accepted 22 July 2013 ABSTRACT Malignant schwannoma (MPNST) is a rare tumor. Many of these cases occur in patients with neurofibromatosis type I (NF-1) and they usually present as a mass lesion which rapidly increase in size with or without neurological symptoms. Here we present an unusual case of MPNST along the radial nerve in which the patient has no underlying neurofibromatosis type I. Keywords: Malignant Schwannoma; MPNST; Radial Nerve.
CASE REPORT
The patient developed complete radial nerve palsy below spiral groove with irritative night pain over the surgical site. MRI found segmental thickenings of the radial nerve between the spiral groove supinator muscles. She was referred to our unit for management two years later because of persistent pain and lack of neurological recovery. Exploration of right radial nerve with tendon transfer was done. No true mass lesion was found and histology of the excised scar tissue was benign traumatic neuroma with inflammatory changes. The hand and finger extension weakness improved after the tendon transfer but the pain and numbness persisted. Her condition stayed static until four years from the second
A 59-year-old woman visited an orthopedic surgeon for a right arm mass which increased in size for a few years. Initial examination found two vague noudules over the right lateral arm with positive Tinel’s sign. Ultrasound revealed two elongated hypoechoic thickening of the radial nerve at the lateral aspect of the mid humerus and near the level of the elbow, respectively. During surgical exploration the right radial nerve and perineural tissue were found to be edematous, but there was no discrete lump. Histological section of perineural tissue and fascicle segment revealed features consistent with inflammatory neuropathy. There was no evidence of malignancy (Fig. 1).
Correspondence to: Dr. Yu Chung Wong, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong, China. Tel: (þ 852) 6484-9834, E-mail: [email protected] 95
February 26, 2014
96
11:05:35am
WSPC/135-HS
1472002
FA1
Y. C. Wong et al.
(A)
Hand Surg. 2014.19:95-97. Downloaded from www.worldscientific.com by MCGILL UNIVERSITY on 02/04/15. For personal use only.
Fig. 1 Section of the excised portion of the radial nerve, showing focal spindle cell proliferation and chronic inflammation.
operation, she complained of increasing pain over the right forearm and first web space. Ultrasound and MRI showed three radial nerve tumors along the course of the right radial nerve from the spiral groove to the supinator muscles around 2–3 cm in diameter with features of sarcomatous changes and a thickened portion proximally. Ultrasound guided core biopsy of the largest revealed closely packed spindle tumor cells stained focally for S100, favoured malignant schwannoma. PET scan revealed increased uptake along the radial nerve from elbow to brachial plexus and a segment of spinal cord, with three FDG-avid masses along right arm, suggesting the
Fig. 2
The three FDG-avid mass along the right radial nerve.
(B) Fig. 3 (A) Grossly swollen radial nerve with nodularity on palpation. (B) Tumor and the triceps removed en-bloc.
possibility that posterior cord and corresponding spinal roots and cord segment may also be involved (Fig. 2). The patient received the third operation. Intra-operatively the longest tumor measured about 8 4 cm at proximal arm region with another distal lesion at the distal arm level. The radial nerve proximal to the proximal arm lesion was swollen with nodularity felt on palpation (Fig. 3A). Posterior compartectomy was performed, with the proximal radial nerve divided at the quadrangular space level with the axillary nerve preserved (Fig. 3B). The tumor shows a light yellowish-grey firm cut surface (Fig. 4A). Histologically, it exhibited typical features of malignant peripheral nerve sheath tumor, comprising interlacing fascicles of closely packed spindle cells with hyperchromatic nuclei (Fig. 4B). The resection margins were clear. She received a course of post-operative radiotherapy. Latest follow up MRI done at eight months post op found no local recurrence.
February 26, 2014
11:05:40am
WSPC/135-HS
FA1
1472002
Hand Surg. 2014.19:95-97. Downloaded from www.worldscientific.com by MCGILL UNIVERSITY on 02/04/15. For personal use only.
Malignant Schwannoma of the Radial Nerve with Unusual Presentation
(A)
97
(B)
Fig. 4 (A) The specimen consists of the tumor in the middle of the thickened radial nerve. The tumor shows a light yellowish-grey firm cut surface. (B) Microscopic appearance of the tumor, showing interlacing fascicles of closely packed spindle cells with hyperchromatic nuclei.
DISCUSSION Our case’s presentation was unusual in which it presented with 10 years’ of multiple \masses" in the arm which were more or less constant in size in serial imaging studies with multiple benign biopsies. There is no evidence that the MPNST arise from malignant transformation of a pre-existing schwannoma. The first nerve biopsy showed features compatible with inflammatory neuropathy and the second biopsy was a benign traumatic neuroma with inflammatory changes. Malignant transformation of a benign schwannoma is extremely rare and only few case reports exist in the literature.1–3 Neurofibromatosis type I (NF-I) is a known risk factor for MPNST with up to 40% of MPNST patient has underlying NF-I.4 MPNST usually develops from pre-existing nodular or diffuse plexiform neurofibroma. Our patient did not meet the diagnostic criteria of NF-1. However, the presence of extensive macroscopic nodular thickenings in the involved nerve is compatible with the nerve biopsy findings of NF-1 reported in the literature. A study conducted by King et al. suggested that MPNST can occur without a previous history of preexisting plexiform neurofibroma in individuals with NF-1.5 A case of NF-1 sub form of spinal neurofibromatosis which presented as MPNST without cutaneous features of NF-1 has been reported, in which genetic analysis revealed NF-1 related mutations.6 Further clinical or laboratory studies are required in this case to evaluate the possible association with NF-1.
This case illustrates that any patient with a peripheral mass with persistent symptoms, even if previous biopsy and imaging investigations showed benign pathology, should continue their follow-up. Any change in the symptoms or the size of the mass should alert the doctor about the possibility of malignant transformation or a new onset malignancy.
References 1. Mikami Y, Hidaka T, Akisada T, Takemoto T, Irei I, Manabe T, Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma. Case report with an immunohistochemical study, Pathol Int 50(2):156– 161, 2000. 2. Nayler SJ, Leiman G, Omar T, Cooper K, Malignant transformation in a schwannoma, Histopathology 29(2):189–192, 1996. 3. Woodruff JM, Selig AM, Crowley K, Allen PW, Schwannoma (neurilemoma) with malignant transformation. A rare, distinctive peripheral nerve tumor, Am J Surg Pathol 18(9):882–895, 1994. 4. Sordillo PP, Helson L, Hajdu SI, Magill GB, Kosloff C, Golbey RB, Beattie EJ, Malignant schwannoma — Clinical characteristics, survival, and response to therapy, Cancer 47(10):2503–2509, 1981. 5. King AA, Debaun MR, Riccardi VM, Gutmann DH, Malignant peripheral nerve sheath tumors in neurofibromatosis 1, Am J Med Genet 93(5):388– 392, 2000. 6. Fauth C, Kehrer-Sawatzki H, Zatkova A, Machherndl-Spandl S, Messiaen L, Amann G, Hainfellner JA, Wimmer K, Two sporadic spinal neurofibromatosis patients with malignant peripheral nerve sheath tumour, Eur J Med Genet 52(6):409–414, 2009.
11:05:34am
WSPC/135-HS
FA1
1472002
Hand Surgery, Vol. 19, No. 1 (2014) 95–97 © World Scientific Publishing Company DOI: 10.1142/S0218810414720022
MALIGNANT SCHWANNOMA OF THE RADIAL NERVE WITH UNUSUAL PRESENTATION: A CASE REPORT Yu Chung Wong,* Pak Cheong Ho,* Wing Lim Tse,* Louis Tsun Cheung Chow† and Clara Wing Yee Wong* *Department
Hand Surg. 2014.19:95-97. Downloaded from www.worldscientific.com by MCGILL UNIVERSITY on 02/04/15. For personal use only.
†Department
of Orthopaedics and Traumatology
of Anatomical and Cellular Pathology Prince of Wales Hospital Hong Kong, China
Received 25 May 2013; Revised 21 July 2013; Accepted 22 July 2013 ABSTRACT Malignant schwannoma (MPNST) is a rare tumor. Many of these cases occur in patients with neurofibromatosis type I (NF-1) and they usually present as a mass lesion which rapidly increase in size with or without neurological symptoms. Here we present an unusual case of MPNST along the radial nerve in which the patient has no underlying neurofibromatosis type I. Keywords: Malignant Schwannoma; MPNST; Radial Nerve.
CASE REPORT
The patient developed complete radial nerve palsy below spiral groove with irritative night pain over the surgical site. MRI found segmental thickenings of the radial nerve between the spiral groove supinator muscles. She was referred to our unit for management two years later because of persistent pain and lack of neurological recovery. Exploration of right radial nerve with tendon transfer was done. No true mass lesion was found and histology of the excised scar tissue was benign traumatic neuroma with inflammatory changes. The hand and finger extension weakness improved after the tendon transfer but the pain and numbness persisted. Her condition stayed static until four years from the second
A 59-year-old woman visited an orthopedic surgeon for a right arm mass which increased in size for a few years. Initial examination found two vague noudules over the right lateral arm with positive Tinel’s sign. Ultrasound revealed two elongated hypoechoic thickening of the radial nerve at the lateral aspect of the mid humerus and near the level of the elbow, respectively. During surgical exploration the right radial nerve and perineural tissue were found to be edematous, but there was no discrete lump. Histological section of perineural tissue and fascicle segment revealed features consistent with inflammatory neuropathy. There was no evidence of malignancy (Fig. 1).
Correspondence to: Dr. Yu Chung Wong, Department of Orthopaedics and Traumatology, Prince of Wales Hospital, 30-32 Ngan Shing Street, Shatin, NT, Hong Kong, China. Tel: (þ 852) 6484-9834, E-mail: [email protected] 95
February 26, 2014
96
11:05:35am
WSPC/135-HS
1472002
FA1
Y. C. Wong et al.
(A)
Hand Surg. 2014.19:95-97. Downloaded from www.worldscientific.com by MCGILL UNIVERSITY on 02/04/15. For personal use only.
Fig. 1 Section of the excised portion of the radial nerve, showing focal spindle cell proliferation and chronic inflammation.
operation, she complained of increasing pain over the right forearm and first web space. Ultrasound and MRI showed three radial nerve tumors along the course of the right radial nerve from the spiral groove to the supinator muscles around 2–3 cm in diameter with features of sarcomatous changes and a thickened portion proximally. Ultrasound guided core biopsy of the largest revealed closely packed spindle tumor cells stained focally for S100, favoured malignant schwannoma. PET scan revealed increased uptake along the radial nerve from elbow to brachial plexus and a segment of spinal cord, with three FDG-avid masses along right arm, suggesting the
Fig. 2
The three FDG-avid mass along the right radial nerve.
(B) Fig. 3 (A) Grossly swollen radial nerve with nodularity on palpation. (B) Tumor and the triceps removed en-bloc.
possibility that posterior cord and corresponding spinal roots and cord segment may also be involved (Fig. 2). The patient received the third operation. Intra-operatively the longest tumor measured about 8 4 cm at proximal arm region with another distal lesion at the distal arm level. The radial nerve proximal to the proximal arm lesion was swollen with nodularity felt on palpation (Fig. 3A). Posterior compartectomy was performed, with the proximal radial nerve divided at the quadrangular space level with the axillary nerve preserved (Fig. 3B). The tumor shows a light yellowish-grey firm cut surface (Fig. 4A). Histologically, it exhibited typical features of malignant peripheral nerve sheath tumor, comprising interlacing fascicles of closely packed spindle cells with hyperchromatic nuclei (Fig. 4B). The resection margins were clear. She received a course of post-operative radiotherapy. Latest follow up MRI done at eight months post op found no local recurrence.
February 26, 2014
11:05:40am
WSPC/135-HS
FA1
1472002
Hand Surg. 2014.19:95-97. Downloaded from www.worldscientific.com by MCGILL UNIVERSITY on 02/04/15. For personal use only.
Malignant Schwannoma of the Radial Nerve with Unusual Presentation
(A)
97
(B)
Fig. 4 (A) The specimen consists of the tumor in the middle of the thickened radial nerve. The tumor shows a light yellowish-grey firm cut surface. (B) Microscopic appearance of the tumor, showing interlacing fascicles of closely packed spindle cells with hyperchromatic nuclei.
DISCUSSION Our case’s presentation was unusual in which it presented with 10 years’ of multiple \masses" in the arm which were more or less constant in size in serial imaging studies with multiple benign biopsies. There is no evidence that the MPNST arise from malignant transformation of a pre-existing schwannoma. The first nerve biopsy showed features compatible with inflammatory neuropathy and the second biopsy was a benign traumatic neuroma with inflammatory changes. Malignant transformation of a benign schwannoma is extremely rare and only few case reports exist in the literature.1–3 Neurofibromatosis type I (NF-I) is a known risk factor for MPNST with up to 40% of MPNST patient has underlying NF-I.4 MPNST usually develops from pre-existing nodular or diffuse plexiform neurofibroma. Our patient did not meet the diagnostic criteria of NF-1. However, the presence of extensive macroscopic nodular thickenings in the involved nerve is compatible with the nerve biopsy findings of NF-1 reported in the literature. A study conducted by King et al. suggested that MPNST can occur without a previous history of preexisting plexiform neurofibroma in individuals with NF-1.5 A case of NF-1 sub form of spinal neurofibromatosis which presented as MPNST without cutaneous features of NF-1 has been reported, in which genetic analysis revealed NF-1 related mutations.6 Further clinical or laboratory studies are required in this case to evaluate the possible association with NF-1.
This case illustrates that any patient with a peripheral mass with persistent symptoms, even if previous biopsy and imaging investigations showed benign pathology, should continue their follow-up. Any change in the symptoms or the size of the mass should alert the doctor about the possibility of malignant transformation or a new onset malignancy.
References 1. Mikami Y, Hidaka T, Akisada T, Takemoto T, Irei I, Manabe T, Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma. Case report with an immunohistochemical study, Pathol Int 50(2):156– 161, 2000. 2. Nayler SJ, Leiman G, Omar T, Cooper K, Malignant transformation in a schwannoma, Histopathology 29(2):189–192, 1996. 3. Woodruff JM, Selig AM, Crowley K, Allen PW, Schwannoma (neurilemoma) with malignant transformation. A rare, distinctive peripheral nerve tumor, Am J Surg Pathol 18(9):882–895, 1994. 4. Sordillo PP, Helson L, Hajdu SI, Magill GB, Kosloff C, Golbey RB, Beattie EJ, Malignant schwannoma — Clinical characteristics, survival, and response to therapy, Cancer 47(10):2503–2509, 1981. 5. King AA, Debaun MR, Riccardi VM, Gutmann DH, Malignant peripheral nerve sheath tumors in neurofibromatosis 1, Am J Med Genet 93(5):388– 392, 2000. 6. Fauth C, Kehrer-Sawatzki H, Zatkova A, Machherndl-Spandl S, Messiaen L, Amann G, Hainfellner JA, Wimmer K, Two sporadic spinal neurofibromatosis patients with malignant peripheral nerve sheath tumour, Eur J Med Genet 52(6):409–414, 2009.
