International Urology and Nephrology 22 (2), pp. 107-- 111 (1990)
Solitary Benign Schwannoma in the Psoas Muscle U . KUYUMCUOGLU, C. GERMIYANOGLU Department of Urology, Ankara State Hospital, Ankara, Turkey (Received January 24, 1989) Solitary benign schwannoma in the psoas muscle is extremely rare. Here we present a case report of a woman who had solitary benign schwannoma in the psoas muscle not associated with von Recklinghausen's disease. This is the fifth case reported in the literature.
Schwannomas are the most common neurogenic tumours and they usually occur in the second to sixth decades of life [3, 4]. In 1910, Verocay stated that these tumours arise from the Schwann cells, but unfortunately misnamed them as neurinomas [1 ]. Later on, Masson agreed with this entity but coined them schwannomas [9]. Theoretically, the tumour may affect almost any organ or nerve trunk which include Schwann cells [1, 5]. The predominant sites of involvement are the head and neck regions, extremities and the mediastinum [2, 7, 15]. Approximately 3 ~ of schwannomas occur in the retroperitoneum [3]. This case is the fifth solitary benign schwannoma of the psoas muscle in the retroperitoneum [1 ].
Case report In 1986, a patient with solitary benign schwannoma in the psoas muscle was treated at the Department of Urology, Ankara State Hospital. The clinical, radiological, laboratory and morphological findings are summarized below. G. U., a female, aged 35 (Record No. 0782/86) was evaluated because of a right flank pain radiating to the inguinal region for a year which did not respond to conservative measures. There was no history of major trauma. On physical examination a hard, slightly tender, fixed mass about 10 cm in diameter was found in the right hypochondrium. Routine laboratory tests including haemogram, urinalysis, blood chemistry revealed nothing abnormal. On IVP the right kidney was displaced superiorly by a lesion which was later defined by ultrasonography as a nonhomogeneous mass of 9.5 cm in diameter in the upper part of the right psoas muscle (Figs 1, 2). The excised tumour was firm, yellowish and well circumscribed. Histologic diagnosis confirmed a benign schwannoma (Fig. 3). Unfortunately, the patient did not attend our Department for follow-up, thus we have no evidence of tumour recurrence. 1"
VSP, Utrecht Akad$miai Kiad6, Budapest
108
Kuyumcuogfu, GermLvanoglu: S c h w a n n o m a in the psoas
Fig. 1. Urogram: Medial deviation of the right ureter and bulge in the right psoas shadow
Discussion
Schwannomas are the most common among neurogenic tumours, arising from Sehwann cells of the nerve sheaths. They are infrequently found in the retroperitoneum: approximately 4% of all retroperitoneal tumours are schwannomas [3]. They are also known as neurilemmoma, neurinoma, encapsulated neurofibroma, peripheral fibroblastoma, peripheral glioma, solitary nerve sheath tumour or perineural fibroblastoma [1, 3, 8, 13]. They are equally seen in either sex.
A schwannoma exerts its pathologic action by compressing the adjacent structures without invasion [3]. Extirpation of the tumour is curative but recurrence has been reported [10]. Malignancy in a solitary sehwannoma is rare. It appears more frequently in multiple peripheral nerve sheath tumours seen ia von Recklinghausen's disease, i. e. 50 % of malignant sehwannomas showing anaplastie International Urology and Nephrology 22, 1990
Kuyumcuoglu, Germi),anoglu: Sckwannoma #~ the l~SOaS
109
Fig. 2. Sagittal sonogram: Echo-poor mass
changes microscopically have a tendency to recur [3]. Schwannomas are solid, well circumscribed and encapsulated. Cystic degeneration with areas of haemorrhage and necrosis may occur if the tumcnr is large [3]. Light microscopic examination of these tumours reveals a composition of dense and loose meshed tissues and palisades of tumcur cells with fusiform and ovoid nuclei. The dense (Antoni A) and the loose meshed (Antoni B) cells are surrounded by a fibrous capsule [1, 31. Only 4 patients with schwannoma in the psoas muscle have been described previously. Their age ranged beween 29 and 53 years and only one was a female in whom the tumour was incidentally detected [1, 6, 14]. The male cases showed symptoms associated with the presence of a mass. In one case, leucocytosis (12,200/cumm) was found. All of them were explored and the tumour was found to be surrounded by a fibrous capsule. Ultrasonography was performed in one case and showed a non-homogeneous hypoechoic mass with a thick wall. In one of 2 patients angiography showed evidence of abnormal vascularity. International Urology and Nephrology 22, 1990
110
K u y u m c u o y l u , Germiyanoolu : S c h w a n n o m a in the psoas
Fig. 3. Microscopic appearance of nuclear palisading
In one patient CT was performed, showing well-defined hypodense mass in the psoas muscle [1 ]. In our patient IVP and ultrasonography were performed. Computerized tomography was not accessible. As mentioned previously, pyelograms disclosed a lesion which displaced the right kidney superiorly and was defined by ultrasonography as a non-homogeneous mass, 9.5 cm in diameter. Macroscopic and microscopic findings paralleled the cases in literature. Stout [12] stated that 18~o of solitary schwannomas coexist with neurofibromatosis. If the patient has neurofibromatosis, von Recklinghausen's disease must be kept in mind. The occurrence of similar lesions in 5 patients leads us to suggest that following diagnosis the treatment of a solitary benign schwannoma is surgical. Generally, the patients should be free of symptoms after such an intervention, and we think that this explains why our patient failed to show up in the follow-up period. A review of the literature disclosed that ultrasonography and tomography in suspected cases of a retroperitoneal tumour not only localize the site of the mass lesion but also help to plan the approach to the tumour. The tendency of schwannomas to recur must be also considered and follow-up should be provided.
International Urology and Nephrology 22, 1990
Kuyumcuoylu, Germiyanoylu : Schwannoma in the psoas
111
References 1. Claes, H., Oyen, R., Stessens, R., Vereecken, R.: Solitary benign schwannoma in the psoas muscle. J. UroL, 137, 753 (1987). 2. Das Gupta, T. K., Brasfield, R. D., Strong, E. W., Hajdu, S. I. : Benign solitary schwannomas (neurilemmomas). Cancer, 24, 355 (1969). 3. Donnal, J. F., Baker, M. E., Mahony, B. S., Leight, G. S. : Benign retroperitoneal schwannoma. Urology, 31, 332 (1988). 4. Felix, E. L., Wood, D. X., Das Gupta, T. K.: Tumors of the retroperitoneum. Curt. Probl. Cancer, 6, 3 (1981). 5. Gooder, P., Farrington, F. : Extracranial neurilemmomata of the head and neck. or. Laryngol. OtoL, 94, 243 (1980). 6. Johenning, P. W., D'Angelo, J.: Neurilemmoma and the urologist. J. UroL, 109, 377 (1973). 7. Katz, A. D., Passy, V., Kaplan, L.: Neurogenous neoplasms of major nerves of face and neck. Arch. Surg., 103, 51 (1971). 8. Kragh, L. V., Soule, E. H., Masson, J. K.: Benign and malignant neurilemmomas of the head and neck. Surg. Gynecol. Obstet., I l l , 211 (1960). 9. Masson, P. : Experimental and spontaneous schwannomas (peripheral gliomas). Am. J. PathoL, 8, 367 (1932). 10. McCarthy, S., Duray, P. : Giant retroperitoneal neurilemmoma: a rare cause of digestive tract symptoms. J. Clin. Gastroenterol., 5, 343 (1983). 11. Sordillo, P. P., Helson, L., Hajdu, S. I., Magill, G. B., Kosloff, C., Golbey, R. B., Beattie, E. J.: Malignant schwannoma -- clinical characteristics, survival, and response to therapy. Cancer, 47, 2503 (1981). 12. Stout, A. P.: The peripheral manifestations of the specific nerve sheath tumor (neurilemmoma). Am. J. Cancer, 24, 751 (1935). 13. Stout, A. P. : Neurofibroma and neurilemmoma. Clin. Proc., 5, 1 (1946). 14. Syred, D. R.: Neurilemmoma within psoas. Br. J. Radiol., 25, 108 (1952). 15. Whitaker, W. G., Droulias, C.: Benign encapsulated neurilemmoma: a report of 76 cases. Am. Sur#., 42, 675 (1976).
International Urology and Nephrolo#y 22, 1990
Solitary Benign Schwannoma in the Psoas Muscle U . KUYUMCUOGLU, C. GERMIYANOGLU Department of Urology, Ankara State Hospital, Ankara, Turkey (Received January 24, 1989) Solitary benign schwannoma in the psoas muscle is extremely rare. Here we present a case report of a woman who had solitary benign schwannoma in the psoas muscle not associated with von Recklinghausen's disease. This is the fifth case reported in the literature.
Schwannomas are the most common neurogenic tumours and they usually occur in the second to sixth decades of life [3, 4]. In 1910, Verocay stated that these tumours arise from the Schwann cells, but unfortunately misnamed them as neurinomas [1 ]. Later on, Masson agreed with this entity but coined them schwannomas [9]. Theoretically, the tumour may affect almost any organ or nerve trunk which include Schwann cells [1, 5]. The predominant sites of involvement are the head and neck regions, extremities and the mediastinum [2, 7, 15]. Approximately 3 ~ of schwannomas occur in the retroperitoneum [3]. This case is the fifth solitary benign schwannoma of the psoas muscle in the retroperitoneum [1 ].
Case report In 1986, a patient with solitary benign schwannoma in the psoas muscle was treated at the Department of Urology, Ankara State Hospital. The clinical, radiological, laboratory and morphological findings are summarized below. G. U., a female, aged 35 (Record No. 0782/86) was evaluated because of a right flank pain radiating to the inguinal region for a year which did not respond to conservative measures. There was no history of major trauma. On physical examination a hard, slightly tender, fixed mass about 10 cm in diameter was found in the right hypochondrium. Routine laboratory tests including haemogram, urinalysis, blood chemistry revealed nothing abnormal. On IVP the right kidney was displaced superiorly by a lesion which was later defined by ultrasonography as a nonhomogeneous mass of 9.5 cm in diameter in the upper part of the right psoas muscle (Figs 1, 2). The excised tumour was firm, yellowish and well circumscribed. Histologic diagnosis confirmed a benign schwannoma (Fig. 3). Unfortunately, the patient did not attend our Department for follow-up, thus we have no evidence of tumour recurrence. 1"
VSP, Utrecht Akad$miai Kiad6, Budapest
108
Kuyumcuogfu, GermLvanoglu: S c h w a n n o m a in the psoas
Fig. 1. Urogram: Medial deviation of the right ureter and bulge in the right psoas shadow
Discussion
Schwannomas are the most common among neurogenic tumours, arising from Sehwann cells of the nerve sheaths. They are infrequently found in the retroperitoneum: approximately 4% of all retroperitoneal tumours are schwannomas [3]. They are also known as neurilemmoma, neurinoma, encapsulated neurofibroma, peripheral fibroblastoma, peripheral glioma, solitary nerve sheath tumour or perineural fibroblastoma [1, 3, 8, 13]. They are equally seen in either sex.
A schwannoma exerts its pathologic action by compressing the adjacent structures without invasion [3]. Extirpation of the tumour is curative but recurrence has been reported [10]. Malignancy in a solitary sehwannoma is rare. It appears more frequently in multiple peripheral nerve sheath tumours seen ia von Recklinghausen's disease, i. e. 50 % of malignant sehwannomas showing anaplastie International Urology and Nephrology 22, 1990
Kuyumcuoglu, Germi),anoglu: Sckwannoma #~ the l~SOaS
109
Fig. 2. Sagittal sonogram: Echo-poor mass
changes microscopically have a tendency to recur [3]. Schwannomas are solid, well circumscribed and encapsulated. Cystic degeneration with areas of haemorrhage and necrosis may occur if the tumcnr is large [3]. Light microscopic examination of these tumours reveals a composition of dense and loose meshed tissues and palisades of tumcur cells with fusiform and ovoid nuclei. The dense (Antoni A) and the loose meshed (Antoni B) cells are surrounded by a fibrous capsule [1, 31. Only 4 patients with schwannoma in the psoas muscle have been described previously. Their age ranged beween 29 and 53 years and only one was a female in whom the tumour was incidentally detected [1, 6, 14]. The male cases showed symptoms associated with the presence of a mass. In one case, leucocytosis (12,200/cumm) was found. All of them were explored and the tumour was found to be surrounded by a fibrous capsule. Ultrasonography was performed in one case and showed a non-homogeneous hypoechoic mass with a thick wall. In one of 2 patients angiography showed evidence of abnormal vascularity. International Urology and Nephrology 22, 1990
110
K u y u m c u o y l u , Germiyanoolu : S c h w a n n o m a in the psoas
Fig. 3. Microscopic appearance of nuclear palisading
In one patient CT was performed, showing well-defined hypodense mass in the psoas muscle [1 ]. In our patient IVP and ultrasonography were performed. Computerized tomography was not accessible. As mentioned previously, pyelograms disclosed a lesion which displaced the right kidney superiorly and was defined by ultrasonography as a non-homogeneous mass, 9.5 cm in diameter. Macroscopic and microscopic findings paralleled the cases in literature. Stout [12] stated that 18~o of solitary schwannomas coexist with neurofibromatosis. If the patient has neurofibromatosis, von Recklinghausen's disease must be kept in mind. The occurrence of similar lesions in 5 patients leads us to suggest that following diagnosis the treatment of a solitary benign schwannoma is surgical. Generally, the patients should be free of symptoms after such an intervention, and we think that this explains why our patient failed to show up in the follow-up period. A review of the literature disclosed that ultrasonography and tomography in suspected cases of a retroperitoneal tumour not only localize the site of the mass lesion but also help to plan the approach to the tumour. The tendency of schwannomas to recur must be also considered and follow-up should be provided.
International Urology and Nephrology 22, 1990
Kuyumcuoylu, Germiyanoylu : Schwannoma in the psoas
111
References 1. Claes, H., Oyen, R., Stessens, R., Vereecken, R.: Solitary benign schwannoma in the psoas muscle. J. UroL, 137, 753 (1987). 2. Das Gupta, T. K., Brasfield, R. D., Strong, E. W., Hajdu, S. I. : Benign solitary schwannomas (neurilemmomas). Cancer, 24, 355 (1969). 3. Donnal, J. F., Baker, M. E., Mahony, B. S., Leight, G. S. : Benign retroperitoneal schwannoma. Urology, 31, 332 (1988). 4. Felix, E. L., Wood, D. X., Das Gupta, T. K.: Tumors of the retroperitoneum. Curt. Probl. Cancer, 6, 3 (1981). 5. Gooder, P., Farrington, F. : Extracranial neurilemmomata of the head and neck. or. Laryngol. OtoL, 94, 243 (1980). 6. Johenning, P. W., D'Angelo, J.: Neurilemmoma and the urologist. J. UroL, 109, 377 (1973). 7. Katz, A. D., Passy, V., Kaplan, L.: Neurogenous neoplasms of major nerves of face and neck. Arch. Surg., 103, 51 (1971). 8. Kragh, L. V., Soule, E. H., Masson, J. K.: Benign and malignant neurilemmomas of the head and neck. Surg. Gynecol. Obstet., I l l , 211 (1960). 9. Masson, P. : Experimental and spontaneous schwannomas (peripheral gliomas). Am. J. PathoL, 8, 367 (1932). 10. McCarthy, S., Duray, P. : Giant retroperitoneal neurilemmoma: a rare cause of digestive tract symptoms. J. Clin. Gastroenterol., 5, 343 (1983). 11. Sordillo, P. P., Helson, L., Hajdu, S. I., Magill, G. B., Kosloff, C., Golbey, R. B., Beattie, E. J.: Malignant schwannoma -- clinical characteristics, survival, and response to therapy. Cancer, 47, 2503 (1981). 12. Stout, A. P.: The peripheral manifestations of the specific nerve sheath tumor (neurilemmoma). Am. J. Cancer, 24, 751 (1935). 13. Stout, A. P. : Neurofibroma and neurilemmoma. Clin. Proc., 5, 1 (1946). 14. Syred, D. R.: Neurilemmoma within psoas. Br. J. Radiol., 25, 108 (1952). 15. Whitaker, W. G., Droulias, C.: Benign encapsulated neurilemmoma: a report of 76 cases. Am. Sur#., 42, 675 (1976).
International Urology and Nephrolo#y 22, 1990
