Malignant Schwannoma--D. Herness, M. A. Posner and G. Steiner
MALIGNANT
SCHWANNOMA
D. HERNESS, M. A. P O S N E R and G. STEINER, New York
The nerve at (a) (b) (c)
SUMMARY following case of solitary malignant Schwannoma arising from the ulnar the lower third of the forearm presents three main points: Difficulties in differential diagnosis at early stages. Unusual clinical findings of ulnar palsy. Clinical and pathological findings leading to an above elbow amputation.
CASE REPORT A forty-eight years old policeman was in good health until 1968 when he first noted a "growth" on the volar aspect of his left forearm. The patient attributed his problems to trauma in 1963 when he was struck on his forearm with a club. The mass was excised in 1968 and a pathological diagnosis of neurofibroma was made.. It recurred shortly thereafter, and was excised again in 1970 with the same diagnosis. He remained asymptomatic until 1973 when he noticzd numbness over the ulnar nerve distribution, marked weakness of grip, and a large forearm mass. Examination in February 1974 showed the typical signs of a tow ulnar nerve palsy including marked atrophy of the intrinsic muscles, and impaired sensation in the ulnar nerve distribution in the hand (Fig. 1). A mass measuring 3 x 3 centimetres was felt over the volar-ulnar aspect of the distal forearm. X-ray examination showed (Fig. 2) a soft tissue mass with no bony involvement of either the radius or the ulna. At operation in March 1974, the tumour was found to arise directly from the ulnar nerve. The proximal portion of the nerve was markedly enlarged for a distance of about twelve centimetres (Fig. 3), and its consistency was exceedingly firm. Excision was not possible since the nerve fasciculi were directly involved. Although the frozen section was not diagnostic of a malignant tumour, the permanent sections confirmed the pre-operative suspicion of a malignant Schwannoma. There was no evidence of metastases. The invasive state of the tumour was considered as a local extensive recurrence, of stage 2b according to Das Gupta's (1970) classification, requiring limb ablation. A mid humeral amputation was performed and the ulnar nerve was dissected as far proximal as possible into the brachial plexus and divided at that point. The PoSt operative course was uneventful. PATHOLOGICAL EXAMINATION The specimen consisted of a left hand, forearm and distal half of arm. There was an indurated swelling of the ulnar nerve measuring 15 centimetres in length (Fig.. 4). It was located proximally at 2.5 centimetres from the wrist, adherent to the third, fourth and fifth tendons of the flexor digitorum profundus, flexor carpi ulnaris and to the skin. The proximal segment of ulnar nerve, the median and radial nerves were normal. Microscopic examination (Fig. 5) revealed nerve bundles almost completely replaced by a spindle cell proliferation arranged in a dense cellular pattern. A marked degree of nuclear atypism and pleomorphism, and a relatively frequent mitotic rate were observed. The tumour infiltrated the epineurium, with reactive fibrosis. There was however, no evidence of extension beyond the epineurium into the soft tissue of the forearm. Sections of the proximal segment of the ulnar nerve near the elbow were free of tumour.
300
The Hand--Vol. 7
No. 3
1975
Malignant Schwannoma--D. Herness, M. A. Posner and G. Sterner
Fig. 1 ~fhe left hand showing marked atrophy of intrinsic muscles. Fig. 2 X-ray showing a soft tissue mass. Fig. 3 Showing an enlarged ulnar nerve was found with a mass located 2.5 cm proximal to the wrist.
Fig. 4 The ulnar nerve was involved by a large fusiform tumour; the cut surface is grayish, relatively firm and nodular. Fig. 5 Photomicrograph showing a dense spindle cell proliferation with marked degree of cellular pleomorphism and nuclear atypism. T h e slides of the biopsy m a t e r i a l r e m o v e d in 1970 at a n o t h e r h o s p i t a l were reviewed. T h e y s h o w e d s i m i l a r c h a n g e s c o n s i s t e n t with a m a l i g n a n t S c h w a n n o m a . Obviously, i n c o m p l e t e excision of the t u m o u r was the cause of r e p e a t e d r e c u r rences. DISCUSSION
S o l i t a r y m a l i g n a n t S c h w a n n o m a is a r a r e t u m o u r (Das G u p t a 1970), with slight p r e d i l e c t i o n for m a l e s (56°/o), a n d no r a c i a l p r e f e r e n c e . T h e t u m o u r can develop at a n y age b u t the highest p e r c e n t a g e r e c o r d e d is b e t w e e n the t h i r d a n d fifth decades. Clinically, the p r e s e n c e of a " g r o w t h " is usually the r e a s o n for c o n s u l t a t i o n . T h e r e a r e n o t a n y specific findings c h a r a c t e r i s t i c of a m a l i g n a n t S c h w a n n o m a . The Hand--Vol. 7
No. 3
1975
301
Malignant S c h w a n n o m a - - D . Herness, M. A. Posner and G. Steiner
The mass is painless in about two-thirds of the patients. Sensory impairment and motor weakness are rarely seen. The present case fulfilled all the histological criteria for malignant Schwannoma, already established in the literature (D'Agostino 1963; Ghosh 1973; Herkin 1969) (1) The tumour was intimately related to a nerve trunk and formed a swelling within the nerve; (2) There was invasion of the epineurium, as well as extension of the tumour along the ulnar nerve in the forearm. This pattern of extension is well known (D'Agostino; Ghosh; Das G u p t a 1970), and it is important to be aware of this during the removal of the tumour. The ultimate progress is invasive in patients with Von Recklinghausen's disease. Fortunately, this patient had no stigmata of that condition. T r e a t m e n t is surgical. Pre-operative radiation therapy has not proved to be effective. Extensive excision "en bloc" including the tumour and its bed, is essential. This must include attached muscles, neuro-vascular elements, and possibly bone. Local excision of the nerve itself is inadequate. It is also advisable to resect a long segment of the nerve proximal to the tumour. The cut end of the nerve should be examined by frozen section to ensure that the resection had been adequate. Even with extensive resection, local recurrence is not u n c o m m o n (D'Agostino; Ghosh; Das Gupta). Statistics show (D'Agostino; Herkin; Das Gupta) that the treatment of choice for tumours with nodular enlargement in a peripheral nerve is major amputation. The survival after this procedure is much longer than after local excision (Das Gupta). BIBLIOGRAPHY
D'AGOSTINO, A. N., SOULE, E. H. and MILLER, R. H. (1963) Primary Malignant Neoplasms Of Nerves (Malignant Neurilemomas) In Patients Without Manifestations Of Multiple Neurofibromatosis (Von Recklinghausen's Disease). Cancer. Vol. 16, 1003-1014. DAS GUPTA, T. K. and BRASFIELD, R. D. (1970) Solitary Malignant Schwannoma. Annals of Surgery, 171: 419-428. GHOSH, B. C., GHOSH, L., HUVOS, A. G. and FORTNER, J. G. (1973) Malignant Schwannoma. A Clinico-pathologic Study. Cancer. Vol. 31, 184-190. HERKIN, J. C. and REED, R. J. (1969) Tumors of the Peripheral Nervous System. In Atlas Of Tumor Pathology, second series, fasc. 3. Washington, D.C., Armed Forces Institute of Pathology.
302
The H a n d - - V o l . 7
No. 3
1975
MALIGNANT
SCHWANNOMA
D. HERNESS, M. A. P O S N E R and G. STEINER, New York
The nerve at (a) (b) (c)
SUMMARY following case of solitary malignant Schwannoma arising from the ulnar the lower third of the forearm presents three main points: Difficulties in differential diagnosis at early stages. Unusual clinical findings of ulnar palsy. Clinical and pathological findings leading to an above elbow amputation.
CASE REPORT A forty-eight years old policeman was in good health until 1968 when he first noted a "growth" on the volar aspect of his left forearm. The patient attributed his problems to trauma in 1963 when he was struck on his forearm with a club. The mass was excised in 1968 and a pathological diagnosis of neurofibroma was made.. It recurred shortly thereafter, and was excised again in 1970 with the same diagnosis. He remained asymptomatic until 1973 when he noticzd numbness over the ulnar nerve distribution, marked weakness of grip, and a large forearm mass. Examination in February 1974 showed the typical signs of a tow ulnar nerve palsy including marked atrophy of the intrinsic muscles, and impaired sensation in the ulnar nerve distribution in the hand (Fig. 1). A mass measuring 3 x 3 centimetres was felt over the volar-ulnar aspect of the distal forearm. X-ray examination showed (Fig. 2) a soft tissue mass with no bony involvement of either the radius or the ulna. At operation in March 1974, the tumour was found to arise directly from the ulnar nerve. The proximal portion of the nerve was markedly enlarged for a distance of about twelve centimetres (Fig. 3), and its consistency was exceedingly firm. Excision was not possible since the nerve fasciculi were directly involved. Although the frozen section was not diagnostic of a malignant tumour, the permanent sections confirmed the pre-operative suspicion of a malignant Schwannoma. There was no evidence of metastases. The invasive state of the tumour was considered as a local extensive recurrence, of stage 2b according to Das Gupta's (1970) classification, requiring limb ablation. A mid humeral amputation was performed and the ulnar nerve was dissected as far proximal as possible into the brachial plexus and divided at that point. The PoSt operative course was uneventful. PATHOLOGICAL EXAMINATION The specimen consisted of a left hand, forearm and distal half of arm. There was an indurated swelling of the ulnar nerve measuring 15 centimetres in length (Fig.. 4). It was located proximally at 2.5 centimetres from the wrist, adherent to the third, fourth and fifth tendons of the flexor digitorum profundus, flexor carpi ulnaris and to the skin. The proximal segment of ulnar nerve, the median and radial nerves were normal. Microscopic examination (Fig. 5) revealed nerve bundles almost completely replaced by a spindle cell proliferation arranged in a dense cellular pattern. A marked degree of nuclear atypism and pleomorphism, and a relatively frequent mitotic rate were observed. The tumour infiltrated the epineurium, with reactive fibrosis. There was however, no evidence of extension beyond the epineurium into the soft tissue of the forearm. Sections of the proximal segment of the ulnar nerve near the elbow were free of tumour.
300
The Hand--Vol. 7
No. 3
1975
Malignant Schwannoma--D. Herness, M. A. Posner and G. Sterner
Fig. 1 ~fhe left hand showing marked atrophy of intrinsic muscles. Fig. 2 X-ray showing a soft tissue mass. Fig. 3 Showing an enlarged ulnar nerve was found with a mass located 2.5 cm proximal to the wrist.
Fig. 4 The ulnar nerve was involved by a large fusiform tumour; the cut surface is grayish, relatively firm and nodular. Fig. 5 Photomicrograph showing a dense spindle cell proliferation with marked degree of cellular pleomorphism and nuclear atypism. T h e slides of the biopsy m a t e r i a l r e m o v e d in 1970 at a n o t h e r h o s p i t a l were reviewed. T h e y s h o w e d s i m i l a r c h a n g e s c o n s i s t e n t with a m a l i g n a n t S c h w a n n o m a . Obviously, i n c o m p l e t e excision of the t u m o u r was the cause of r e p e a t e d r e c u r rences. DISCUSSION
S o l i t a r y m a l i g n a n t S c h w a n n o m a is a r a r e t u m o u r (Das G u p t a 1970), with slight p r e d i l e c t i o n for m a l e s (56°/o), a n d no r a c i a l p r e f e r e n c e . T h e t u m o u r can develop at a n y age b u t the highest p e r c e n t a g e r e c o r d e d is b e t w e e n the t h i r d a n d fifth decades. Clinically, the p r e s e n c e of a " g r o w t h " is usually the r e a s o n for c o n s u l t a t i o n . T h e r e a r e n o t a n y specific findings c h a r a c t e r i s t i c of a m a l i g n a n t S c h w a n n o m a . The Hand--Vol. 7
No. 3
1975
301
Malignant S c h w a n n o m a - - D . Herness, M. A. Posner and G. Steiner
The mass is painless in about two-thirds of the patients. Sensory impairment and motor weakness are rarely seen. The present case fulfilled all the histological criteria for malignant Schwannoma, already established in the literature (D'Agostino 1963; Ghosh 1973; Herkin 1969) (1) The tumour was intimately related to a nerve trunk and formed a swelling within the nerve; (2) There was invasion of the epineurium, as well as extension of the tumour along the ulnar nerve in the forearm. This pattern of extension is well known (D'Agostino; Ghosh; Das G u p t a 1970), and it is important to be aware of this during the removal of the tumour. The ultimate progress is invasive in patients with Von Recklinghausen's disease. Fortunately, this patient had no stigmata of that condition. T r e a t m e n t is surgical. Pre-operative radiation therapy has not proved to be effective. Extensive excision "en bloc" including the tumour and its bed, is essential. This must include attached muscles, neuro-vascular elements, and possibly bone. Local excision of the nerve itself is inadequate. It is also advisable to resect a long segment of the nerve proximal to the tumour. The cut end of the nerve should be examined by frozen section to ensure that the resection had been adequate. Even with extensive resection, local recurrence is not u n c o m m o n (D'Agostino; Ghosh; Das Gupta). Statistics show (D'Agostino; Herkin; Das Gupta) that the treatment of choice for tumours with nodular enlargement in a peripheral nerve is major amputation. The survival after this procedure is much longer than after local excision (Das Gupta). BIBLIOGRAPHY
D'AGOSTINO, A. N., SOULE, E. H. and MILLER, R. H. (1963) Primary Malignant Neoplasms Of Nerves (Malignant Neurilemomas) In Patients Without Manifestations Of Multiple Neurofibromatosis (Von Recklinghausen's Disease). Cancer. Vol. 16, 1003-1014. DAS GUPTA, T. K. and BRASFIELD, R. D. (1970) Solitary Malignant Schwannoma. Annals of Surgery, 171: 419-428. GHOSH, B. C., GHOSH, L., HUVOS, A. G. and FORTNER, J. G. (1973) Malignant Schwannoma. A Clinico-pathologic Study. Cancer. Vol. 31, 184-190. HERKIN, J. C. and REED, R. J. (1969) Tumors of the Peripheral Nervous System. In Atlas Of Tumor Pathology, second series, fasc. 3. Washington, D.C., Armed Forces Institute of Pathology.
302
The H a n d - - V o l . 7
No. 3
1975
