International Journal of Urology (2000) 7, 467–469
Case Report
Retrovesical leiomyosarcoma SULEYMAN ATAUS,1 ÖZGÜR YAYCIOGLU,1 OKTAY DEMIRKESEN,1 NESRIN UYGUN,2 VELI YALCIN1 AND VURAL SOLOK1 Departments of 1Urology and 2Pathology, Cerrahpas¸a Faculty of Medicine, University of Istanbul, Istanbul, Turkey Abstract
A case of retrovesical leiomyosarcoma in a male patient is described. The preoperative radiological and laboratory studies were inconclusive in determining the primary origin of the tumor. Diagnosis of a malignant tumor with smooth muscle origin was suggested by needle biopsy. However, the definitive diagnosis and the primary site of origin could only be determined by surgical exploration and subsequent histopathologic examination after excision. No sign of recurrence or metastasis was present 12 months after complete surgical resection.
Key words
bladder, diagnosis, leiomyosarcoma, prostate.
Introduction Retrovesical masses can either be cystic or solid. The cystic masses are usually of embryologic origin or they are caused by hydatid disease.1,2 Solid retrovesical masses in men are rare and frequently pose diagnostic difficulties.2 We describe a case of retrovesical solid mass in a male patient in whom definitive diagnosis was possible only with surgery and subsequent histopathological examination.
Case Report A 52-year-old man presented to the general surgery department of our hospital in Istanbul, Turkey, with complaints of constipation and difficulty in defecation for the last 2 years. The patient was referred to the urology department due to suspected prostatic enlargement. Physical examination was unremarkable except for the digital rectal examination (DRE) which revealed a soft non-tender mass between the rectum and the right lobe of the prostate. Urinalysis Correspondence: Dr Özgür Yaycioglu, Ortaklar Cad. Sakizagaci Sok., Eser Ap. No: 6 Daire: 6, 80290 Mecidiyekoy, Istanbul, Turkey. Email:
[email protected] Received 25 November 1999; revision 7 June 2000; accepted 16 June 2000.
and blood biochemistry studies were normal, but the serum prostate-specific antigen level was 9.6 ng/mL (normal < 4.0 ng/mL). Endorectal coil magnetic resonance imaging (MRI) revealed a solid mass in the retrovesical area but it was not possible to determine whether the mass originated from outside the prostate or from within the gland (Fig. 1). Transrectal ultrasound (TRUS) and needle biopsy was performed. Histopathologic examination demonstrated a malignant mesenchymal tumor that consisted of fusiform cells with frequent mitotic figures. Immunohistochemical staining with desmin and smooth muscle actin suggested a smooth muscle origin. No prostatic tissue was detected in the biopsy specimens. The patient was operated on with a clinical diagnosis of retrovesical malignant solid mass of uncertain primary site of origin. At exploration, a 5 ¥ 4 ¥ 3 cm solid mass with well-defined borders was encountered between the rectum and right posterolateral wall of the bladder. The mass was excised and bilateral pelvic lymph node dissection was performed (Fig. 2). On histopathologic examination, the tumor tissue appeared to be composed of elongated cells with wide cytoplasm and centrally located blunt-ended nuclei. The cells were arranged in fascicles and showed mild pleomorphism. Immunohistochemically, desmin and actin staining were positive. The pathologic diagnosis was well-differentiated retrovesical leimyosarcoma
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Fig. 1 Axial magnetic resonance image of the prostate with endorectal coil revealing a mass between the rectum and the right lobe of the prostate gland.
Fig. 3 Tumor cells. (a) Elongated tumor cells arranged in fascicles with wide cytoplasm (H&E; original magnification ¥ 200). (b) Tumor cells have blunt-ended central nuclei and show mild pleomorphism. Mitoses are noted at the central portion of the figure (H&E; original magnification ¥ 400).
Discussion
Fig. 2 Macroscopic appearance of the mass after excision. The 5 ¥ 4 ¥ 2.5 cm tumor is soft and nodular with a well-defined capsule and a degenerated area in the center.
(Figs 3,4). Lymph nodes were negative for metastatic spread. No adjunctive therapy was given to the patient due to complete excision with negative surgical margins. The patient was well with no complaints and no physical or radiologic signs of recurrence or metastasis 12 months after the surgery.
Cystic retrovesical masses are usually of embryologic origin or they are due to hydatid disease. Diagnosis in most of these cases can be made accurately by radiologic and endoscopic examinations.1,2 Solid retrovesical masses in men are rare in the scientific reports, and well-defined guidelines are lacking on diagnosis and treatment of these lesions. Recently, Dahms et al. have reviewed their experience with retrovesical masses in 21 male patients, most of whom had cystic lesions.2 They were able to propose diagnostic guidelines for cystic masses; however, this was not possible for solid masses because of the limited number of cases. They emphasized that laparotomy or needle biopsy was the guiding diagnostic procedure in all cases with solid retrovesical masses.
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identify five such cases reported since 1966.2,4–7 A leiomyosarcoma of gastrointestinal origin, which presented as a retrovesical mass and posed diagnostic difficulties, has also been described.8 Cure is possible with complete surgical resection in cases of retrovesical leiomyosarcoma. Our patient was free of disease 12 months following the operation. This is perhaps possible with early diagnosis when the tumor is small and suitable for complete surgical removal. Neoadjuvant chemotherapy and radiotherapy may be necessary for patients with large tumors in order to decrease the tumor mass and make it amenable to complete surgical resection.6 The prognosis is bad for cases of leiomyosarcoma in which complete excision is not possible and the tumor usually causes death by both local extension and metastatic spread.3,7,9 We conclude that solid retrovesical masses are rare lesions, and preoperative diagnostic procedures may not always identify the origin successfully. Therefore, definitive diagnosis may only be possible with surgery and subsequent histopathologic examination.
References 1
Fig. 4 (a) Strong intracytoplasmic immunoreactivity of tumor cells with desmin; (b) diffuse positive reaction for smooth muscle actin within the tumor (original magnification ¥ 200).
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Preoperative DRE and radiologic studies including endorectal coil MRI were not definitive in identifying the origin of the mass in our patient. The TRUSguided needle biopsy suggested a malignant smooth muscle tumor but it was inconclusive as to whether it was of prostatic or extraprostatic origin. The definitive diagnosis was only possible after surgical exploration in which an extraprostatic mass in the retrovesical area with well-defined borders was located and excised. Histopathologic examination confirmed the diagnosis of leimyosarcoma. Leimyosarcomas are relatively uncommon, accounting for 7% of soft tissue sarcomas, and appear in women more frequently than in men.3 Although reports of prostatic leiomyosarcoma cases are frequent in the scientific reports, extraprostatic primary retrovesical leiomyosarcomas are very rare. We could
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