Genitourinary leiomyomas

Uncommon Detection of Leiomyoma in the Penile Corpus Spongiosum Using FDG PET/CT: A Case Report

ABSTRACT

Primary tumors of the penile corpus spongiosum are rare. Hereby we describe the scintigraphic findings of a case of penile leiomyoma within the corpus spongiosum tissue, which was incidentally detected on FDG PET/CT. The benign neoplasm was growing in close proximity to the urethra showing increased focal FDG uptake on sequential PET/CT studies. Subsequently, the patient experienced obstructive urinary symptoms, and the tumor was resected. We concluded that the possibility of neoplasm should be kept in mind while evaluating a patient with persistent focal penile FDG uptake, which may be the first and only manifestation of the disease.

Paratesticular leiomyoma mimicking an inguinal hernia: A rare case report and literature review

Leiomyomas are considered as a rare, benign, slow-growing, and smooth muscle tumours which may present in all regions in the body. The presentation of leiomyoma in genitourinary tract specifically in paratesticular region is extremely rare. The patients may present with palpable, and painful mass in the inguinal region hence mimicking the nature of inguinal hernia. Herewith, we report our experience of 36-year-old male which had been referred for the suspicion of incarcerated inguinal hernia manifesting with painful mass in the right inguinal and testicular region. During testicular exploration surgery, a benign tumour was incidentally discovered. The lesions were then surgically removed by performing radical orchiectomy with the pathology result confirmed the presence of paratesticular leiomyoma. The post-operative course was uneventful and the patient was discharged on first post-operative day. The patient remained free from metastases or local recurrence after 12 months of regular follow up. This case report demonstrated a rare presentation of paratesticular leiomyoma with misleading manifestation of inguinal hernia. Careful and tailored investigation should be performed to avoid misled diagnosis of this case.

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Paratesticular leiomyoma is a rare benign tumour that may present similarly with ingunal hernia.

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Thorough clinical examination, imaging modalities, histopathology and immunohistochemistry may aid in the diagnosis.

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Surgical exploration is the mainstay treatment of paratesticular leiomyomas.

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Radical orchidectomy may be considered if malignancy is suspected.

Renal leiomyoma: a case report and literature review

Background

Renal leiomyomas are exceptionally rare, benign, mesenchymal tumours originating from smooth muscle in the kidney. Historically, because of their small size, most renal leiomyoma cases were discovered incidentally based on autopsy findings. However, since the advent and improved access to imaging modalities such as ultrasound and computed tomography (CT), renal leiomyomas are being discovered more frequently. Although usually incidental discoveries, clinical presenting signs and symptoms comprise abdominal or flank pain, a palpable flank mass, and haematuria in 20% of those with symptoms.

Case presentation

We study the case of an incidentally found, asymptomatic, left kidney mass that presented in a 60-year-old female. Initial suspicions on CT imaging of either renal cell carcinoma or oncocytoma resulted in a radical nephrectomy of the left kidney. Postoperative pathological examination of the mass revealed a renal leiomyoma; a rare, benign tumour that is mostly indistinguishable from malignant tumours on imaging.

Conclusions

With the current availability of ultrasonography and CT, they are often discovered incidentally, and the radiological differential diagnoses are often inadequate or challenging in such cases. The gold standard management of these suspicious cancer cases is still a radical nephrectomy with postoperative pathological and immunohistochemical analysis. Due to its benign nature, patients enjoy excellent prognoses without recurrence. We discuss and briefly review the relevant literature of the clinical, imaging and pathological features of renal leiomyomas and those of the differential diagnoses.

Scrotal leiomyoma: a rare cause of scrotal swelling

Background

Leiomyomas are benign smooth muscle tumours predominantly found in the uterus. Rarely, they may be located in the ovaries, scrotum, bladder, lungs, vascular structures and spermatic cord.

Case presentation

We managed a 39-year-old man who presented with a year history of progressive right-sided hemiscrotal swelling. The right scrotal mass was excised, and histology showed scrotal leiomyoma.

Conclusion

Scrotal leiomyoma is very rare and challenging to diagnose pre-operatively as a cause of scrotal swelling, but it is amenable to surgical excision.

Typical leiomyoma of the scrotum: A rare case report

INTRODUCTION

Scrotal leiomyomas are benign tumors arising from the dartos layer of the scrotal wall. The exact cause of this tumor is not yet clear. Malignant transformation to leiomyosarcomas has been reported.

CASE PRESENTATION

A 52-year-old male who complained of a painless lump on the right side of the scrotum that lasted 12 years. Physical examination revealed a single, firm, and non-tender, mobile lump on the anterior aspect of the right scrotum. Both testes were normal and no inguinal lymph nodes could be palpated. Ultrasound scan of the scrotum showed a 40 mm × 20 mm hypoechoic, poorly vascular lesion in the scrotum. Under spinal anesthesia, the mass has been excised. Histopathological and immunohistochemical findings were consistent with the diagnosis of scrotal leiomyoma.

DISCUSSION

Leiomyomas may originate from any location in the genitourinary system where there is smooth muscle. Scrotal smooth muscle tumors can be categorized into Leiomyomas, atypical or symplastic leiomyomas, which are not hypercellular and lack mitotic activity, and leiomyosarcomas. Ultrasound is the first-line imaging investigation in patients with suspected scrotal masses. Typical leiomyomas and atypical ones behave similarly. Therefore, they are managed only with surgical excision, while leiomyosarcomas need a wide 3-5 cm margin resection. Both recurrence and malignancy have been described. Close follow-up is required to detect recurrence.

CONCLUSION

Scrotal leiomyoma is a rare benign mesenchymal tumor of the middle-aged men. The current report describes the clinical and histopathological characteristics to help reduce erroneous diagnoses of this rare tumor.

Asynchronous bilateral leiomyomata of tunica vaginalis: A case report

Leiomyomata are smooth muscle tumours that are slow growing and benign.

We report a case of bilateral leiomyomata arising from tunica vaginalis. A 65 year old presented with a 5-year history of a slow growing left testicular mass and underwent radical orchidectomy. He presented again 18 months later with a slow growing right testicular mass and underwent local surgical resection.

In both the cases the diagnosis of tunica vaginalis leiomyoma was determined through subsequent histopathological analysis. We hope to inform urologists to be aware of this benign rare entity as it can be cured through a simple, organ preserving surgical excision.

Leiomyoma arising from the right seminal duct/seminal vesicle-Report of a rare case and review of the literature

We present a case of a patient with a large, symptomatic abdominal tumour, which finally could be classified as a leiomyoma arising from the right seminal duct/seminal vesicle. In computed tomography (CT) scan, it appeared as a 7.5 × 6.5 cm solid, supravesical mass. A cystoscopy as well as bilateral retrograde studies was normal, a transrectal ultrasound-guided biopsy and an ultrasound-guided transabdominal biopsy of the mass were inconclusive. Subsequently, we performed a tumour extirpation through a lower midline laparotomy. Histological examination showed a leiomyoma arising from the right seminal duct or seminal vesicle. In this article, we discuss clinical presentation, findings on imaging and management of this rare benign tumour and review the relevant literature where only 13 similar cases could be identified.

Scrotal sac leiomyoma: Case report of a rare benign scrotal mass

Leiomyomas are benign mesenchymal tumors, the overwhelming majority of which are located in the uterus. Rare cases arise in other organs, including the scrotum, pelvis, bladder, and spermatic cord. This report evaluates the case of a 37-year-old man with a history of prior left inguinal hernia repair, who presented with a painless right scrotal mass. He first noticed the mass approximately 1 year prior to his initial visit. Subsequent ultrasound of the scrotum demonstrated a 5-cm circumscribed, hypoechoic, mildly vascular extratesticular mass located within the right hemiscrotum. Based on the initial imaging, the differential diagnosis included lipoma, adenomatoid tumor, papillary cystadenoma, leiomyoma, fibrous pseudotumor, sarcoid granuloma, sarcoma (including liposarcoma, rhabdosarcoma, or leiomyosarcoma), lymphoma, and an extranumerary testis. The mass had circumscribed margins, suggesting an encapsulated lesion, and was completely separate from the testicle on ultrasound. Despite this, testicular malignancy was not entirely excluded as a diagnosis, although it was considered far less likely. The patient was definitively treated with surgical excision of the mass. Pathology of the surgical specimen confirmed diagnosis of leiomyoma, a rare scrotal mass.

Inguinal canal spermatic cord leiomyoma presenting as an incarcerated inguinal hernia

Leiomyoma is a benign neoplasm originating from smooth muscle cells and is most commonly seen in the uterus, followed by the small bowel and oesophagus. We report a rare case of a 41-year-old male patient with a spermatic cord leiomyoma that presented as an inguinal canal mass mimicking an irreducible inguinal hernia without scrotal involvement. This report highlights the rare presentation and workup of an inguinal mass, importance of intraoperative decision making based on operative findings and the significance of postoperative pathology findings.

Leiomyoma of the deferens: a curious and extremely rare disease

INTRODUCTION

Leiomyomas are rare benign tumors that can occur in the male urinary tract. We present a unique case of leiomyoma of the vas deferens.

CASE DESCRIPTION

We present the clinical case of a 69-year-old patient with a suspected bulk close to the right epididymis, which turned out to be a leiomyoma of the vas deferens. To our knowledge, it is the fourth case in literature.

CONCLUSIONS

A proper identification and the knowledge of this pathology, even if it is a very unusual event, is necessary to avoid a surgical over treatment and preserve the testicle, by removing only the tumor.

Transvaginal Resection of a Bladder Leiomyoma Misdiagnosed with a Vaginal Mass: A Case Report and Literature Review

Bladder leiomyoma is a rare benign tumor and it could be easily misdiagnosed with many other pelvic diseases, especially obstetrical and gynecological diseases; abdominal, laparoscopic, and transurethral resection of bladder leiomyoma have been reported. Herein, we present a case of bladder leiomyoma misdiagnosed with a vaginal mass preoperatively; the mass was isolated, enucleated from the bladder neck, and removed transvaginally; to the best of our knowledge, this is the first case of intramural leiomyoma of bladder neck that has been enucleated transvaginally only without cystotomy.

Leiomyoma of the seminal vesicles: laparoscopic excision

Leiomyoma of the seminal vesicles is an extremely rare type of benign tumor of the genitourinary system and can cause lower urinary tract symptoms. Despite their low incidence, these tumors can be identified with transrectal ultrasound of the seminal vesicles during prostate examination. The removal of these tumors is facilitated by a laparoscopic approach.

Bladder leiomyoma: Presentation, evaluation and treatment

BACKGROUND

Bladder leiomyomas are benign mesenchymal neoplasms and very rare urinary tumours that represent <0.5% of all bladder tumours, with only 250 cases reported worldwide to date. The importance of recognising their characteristic features, leading to their correct treatment, is fundamental. Therefore, we reviewed reports of leiomyomas of the urinary bladder, their causes, clinical presentations, imaging methods and surgical management, updated to 2012.

METHODS

We retrospectively reviewed articles published in the USA, Europe and Asia, from 1953 to date, using PubMed, Medscape, Medline and the several major journals. We report areas of controversies and well-established guidelines.

RESULTS

We reviewed 36 articles that confirmed, with a high level of evidence-based medicine, that the male to female ratio is equal, the cause of bladder leiomyomas remains unknown, and their most common presentation is obstructive uropathy; endovesical tumours are the most common. Their radiological diagnosis can be made by ultrasonography, computed tomography or magnetic resonance imaging. Complete surgical resection is a very effective treatment, associated with almost no recurrence.

CONCLUSION

In symptomatic patients a complete surgical resection can give a very good outcome, with almost no recurrence.

Leiomyoma of the tunica albuginea, a case report of a rare tumour of the testis and review of the literature

Background

Leiomyomas are benign tumours that originate from smooth muscles. They are often seen in the uterus, but also in the renal pelvis, bladder, spermatic cord, epididymis, prostate, scrotum or the glans penis. Leiomyomas of the tunica albuginea are extremely rare.

Case presentation

A 59-year-old white male has noted an asymptomatic tumour on the right side of his scrotal sac for several years. This tumour has increased slowly and caused local scrotal pain. An inguinal incision was performed, in which the hypoplastic testis, the epididymis and the tumour could be easily mobilized. Macroscopically the tumour showed a solid round nonencapsulated whorling cut surface. Histologically the diagnosis of a leiomyoma was made.

Conclusion

We report here a very interesting and rare case of a leiomyoma of the tunica albuginea. Leiomyomas can be a possible differential diagnosis in this area.

Virtual Slides

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Leiomyoma of kidney: An Indian experience with literature review

INTRODUCTION

Leiomyoma of kidney is an exceptional finding in the urinary tract. Though most of these tumors are detected on autopsy, still it remains a diagnostic challenge.

PRESENTATION OF CASE

We report three adult cases of renal leiomyoma in our institute who presented with abdominal mass and haematuria in last 8 years.

DISCUSSION

Leiomyoma has been reported in other organs but renal leiomyoma is rare tumour, though in autopsy series they are second in order of frequency among the renal mesenchymal neoplasms, and few cases have been described in the literature. Still no Indian experience is evaluated on this rare site of occurrence.

CONCLUSION

Considering the difficulty of clinical diagnosis of this tumour, strong suspicion is indicated when a patient presents with voluminous, well circumscribed renal lesions.

Leiomyoma on the shaft of penis

Primary soft tissue tumours of the penis, such as leiomyomas, are very rare. Most present as small and painless but gradually increasing swellings on the penis. To the best of our knowledge, only 9 cases have been reported in the literature so far. This rare pathologic finding, which usually mimics a malignant lesion, should be included in the differential diagnosis of penile neoplasm. Surgical excision of the lesion provides both the histological diagnosis and an effective therapy. We report a case of a large leiomyoma on the shaft of the penis measuring 8x5 cm, which possibly represents the largest reported leiomyoma of the penis in English literature till date.

Leiomyoma of the seminal vesicle

We report a case of leiomyoma of the seminal vesicle in a 74-year-old man who presented with left hemilumbago. Computed tomography and magnetic resonance imaging revealed a mass containing coarse calcification and low signal intensity areas on T1- and T2-weighted images. The clinical features of previously reported cases of leiomyoma of the seminal vesicle are presented, including those of the present case. There remains a lack of consensus regarding surgical resection of leiomyoma of the seminal vesicle.

A rare symplastic or bizarre leiomyoma of the scrotum: a case report and review of the literature

Background

We present a case of a symplastic or "bizarre" leiomyoma of the scrotum. Isolated cases of leiomyomas have been reported arising from the renal pelvis, bladder, spermatic cord, epididymis, prostate as well as the glans penis. However such mesenchymal lesions of the scrotum are very rare.

Case presentation

Macroscopically the tumour was a well-circumscribed grey-white lesion 8.5 cm in size. Because of its peculiar histological characteristics this tumour was assigned as a symplastic or bizarre leiomyoma of the scrotum.

Conclusion

We present this unusual tumour and highlight some important diagnostic and treatment pitfalls related to this rare tumour. This case demonstrates that leiomyomas should be considered in the differential diagnosis of scrotal tumours.

Leiomyoma of the corpus cavernosum of the penis

While soft tissue tumors can occur in the penis, corpus cavernous tumors are rare. Reported cases of corpus cavernous tumors are from metastases of advanced malignancy, such as cancers of the bladder, prostate, rectosigmoid colon, kidney, pancreas, liver, testis and nasopharynx. Primary corpus cavernous tumors are extremely rare and have possibly never been reported before. Herein, we report a case of leiomyoma of the corpus cavernosum. After the diagnosis of leiomyoma was established, total excision of the tumor was not attempted and the tumor remained unchanged in size and shape over a follow-up period of 15 months.

Leiomyomas of the kidney: emphasis on conservative diagnosis and treatment

Leiomyomas are benign mesenchymal tumors that rarely occur in the kidney. We present the reports of three renal leiomyomas diagnosed and treated at our institution during the past 10 years. On the basis of our experience, preoperative diagnosis may be possible through image-guided percutaneous biopsy, and conservative treatment with either expectant management or minimally invasive nephron-sparing surgery should always be considered.

Renal leiomyoma associated with Epstein-Barr virus in a pediatric transplant patient

Renal leiomyoma is a rare smooth muscle tumor of the kidney. An association between Epstein-Barr virus and smooth muscle tumors in immunocompromised patients recently has been recognized. We describe a pediatric renal transplant patient who developed an Epstein-Barr virus-associated renal leiomyoma in his transplant kidney 5 years posttransplantation. Possible factors involved in the tumor pathogenesis in our patient are discussed, including immunosuppression, growth hormone therapy, and Epstein-Barr virus induction.

[Symptomatic leiomyoma of the kidney: renal mass with difficult preoperative diagnosis]

Renal leiomyoma is a benign mesenchymal tumour that, albeit very rare, has to be ruled out when a renal mass has been diagnosed. This tumour can arise from any organ of the genitourinary tract with smooth muscle cells, being the renal capsule the most frequent origin. As its behaviour is not aggressive, nephron-sparing surgery is indicated. However, as it is difficult to preoperatively differentiate the leiomyoma from the adenocarcinoma, the former is commonly diagnosed after examination of the entire organ surgically removed.

Scrotal ultrasonography with emphasis on the extratesticular space: anatomy, embryology, and pathology

Sonography is the imaging modality of choice in detecting and characterizing pathologic conditions affecting the extratesticular space. Although most abnormalities are benign, many may simulate or represent malignant processes. Accurate diagnosis is therefore essential and must be based not only on the sonographic findings but also on accurate clinical history and physical examination findings. This article reviews the anatomy, embryologic development, and pathologic conditions affecting the extratesticular space.

Leiomyoma of the corona glans penis

A 42-year-old man presented with an 8-mm elliptical indolent solid mass on the superior surface of the corona glandis at our institution 3 months after its appearance. The lesion was excised by using a wedge resection performed by a cool blade knife. The subsequent pathologic evaluation defined the lesion as a leiomyoma. Immunohistochemical analysis using the streptavidin-biotin peroxidase technique and immunoreactivity for cytokeratin, S100 protein, and the proliferative marker MIB1 was performed, confirming the pathologic diagnosis. Early local excision of these tumors is indicated because of the trend toward their dimensions increasing quickly, with subsequent difficulties for cosmetic glandis reconstruction.

Leiomyoma of the genitourinary tract

OBJECTIVE

To review our experience and the literature with respect to leiomyomas of the genitourinary tract with special emphasis on the role of the clinical presentation and imaging studies in the differential diagnosis.

MATERIAL AND METHODS

During a period of 35 years in our department, five patients were treated with symptomatic leiomyomas, originating from the renal pelvis, bladder, urethra and epididymis. All the cases were diagnosed after exploration, excision and histological examination of the specimen. Following the presentation of the five cases of leiomyomas of the genitourinary tract, we reviewed the literature with special emphasis on the modern imaging techniques, differential diagnosis and treatment approach.

CONCLUSION

Complete excision followed by histological examination is the most reliable means of distinguishing leiomyoma from other more common and usually malignant tumors of the genitourinary tract.

Leiomyoma in the space of Retzius: a report of 2 cases

Leiomyomas most frequently occur in the genitourinary and gastrointestinal system. This report discusses clinical and pathologic findings of 2 leiomyomas in the pubovesical space, a location that has not been described before. Different operative approaches were used for excision. Immunohistochemical examination for the presence of estrogen and progesterone receptors was performed.

[Large renal leiomyoma]

Renal leiomyomas are uncommon between renal tumors, and they have a benign mesenchymatous origin. Because of their low incidence, unspecific symptomatology an not well-defined iconographic semiology, they often raise problems with differential diagnosis from kidney masses, although they are often big size lessions. We report a patients with incidentally diagnosis of big solid left renal mass, who underwent radical nephrectomy resulting kidney pelvis leiomyoma. Diagnostic, histological and therapeutic aspects are briefly review in literature. Emphasis is made on the relevance of a high index suspicion considering big solid asymptomatic renal masses in middle-age women. Specially in renal tumors with well-defined limits and abscence of locoregional and systemic dissemination. We emphasized usefulness of Magnetic Angioresonance, immunohystochemical test and conservative surgery opportunity in small renal leiomyomas preoperatively confirmed.

Multiple leiomyoma of the renal capsule

Multiple renal capsular leiomyoma is an extremely rare tumour. We describe one such case which was managed by renal sparing surgery.

Scrotal imaging

Scrotal ultrasonography has many indications. Evaluation of testis masses, hydroceles, and extratesticular structures are the most common indications. Color Doppler ultrasound has made assessment of scrotal blood flow possible. This enables the sonographer to make specific diagnoses in cases of acute scrotal pain. Other indications include evaluating infertile men, searching for an undescended testis, and evaluating the traumatized scrotum.

Bilateral synchronous leiomyomas of the testicular tunica albuginea. A case report and review of the literature

Genitourinary leiomyomas are uncommon but may arise from any structure or organ containing smooth muscle. The kidney capsule is the most common location for genitourinary leiomyomas. We report a case of bilateral synchronous leiomyomas of the testicular tunica albuginea.

Leiomyoma of the renal pelvis: Case report

— Leiomyomas of the renal pelvis are rare benign tumours. Their bladder localization has been described in 160 cases, while their pelvic renal localization, according to our literature review, has been reported in just 6 cases. Of these, 5 underwent a nephroureterectomy and 1 conservative surgery, since the diagnostic preoperative examinations indicated urothelial disease. We report a case of fasciculated renal pelvis leiomyoma, in which the clinical aspect and the preoperative imaging indicated this fact and therefore the possibility of a conservative strategy.

Synchronous inverted papilloma and submucosal leiomyoma of the urinary bladder

We report a case of synchronous inverted papilloma and submucosal leiomyoma of the bladder in a 43-year-old man and review the relevant literature.

Leiomyoma of the seminal vesicle

Leiomyoma of the seminal vesicle is exceedingly rare, with only a few cases reported in the literature. To our knowledge we present the first case of primary leiomyoma of the seminal vesicle to be evaluated by magnetic resonance imaging using a rectal coil.

Leiomyoma of bladder: report of case and review of literature

We recently treated a patient with leiomyoma of the bladder and reviewed the 37 most recent cases in the English language literature. Mean patient age was forty-four years. Women made up 76 percent of the patients. Patients presented most commonly with obstructive urinary symptoms (49%), irritative symptoms (38%), hematuria (11%), or flank pain (13%); 19 percent were asymptomatic. Almost all patients had cystoscopy (87%) and intravenous urograms (IVU) (81%), but fewer had masses on bimanual examination (57%), ultrasound (49%), or computed tomography (CT) scan (35%). Most patients were treated with open resection (62%), while 30 percent were treated with transurethral resection (TUR). Almost all patients were cured with a single procedure (89%). Leiomyoma of the bladder is rare and readily cured with excision.

Cortical renal leiomyoma with extension to renal pelvis

We describe a case of renal leiomyoma in a 21-year-old woman who presented with flank pain and hematuria. Urographic and computed tomographic (CT) studies revealed a large right renal mass with polypoid outgrowth protruding into the renal pelvis. Cortical renal leiomyoma with this radiographic manifestation is extremely rare.

Angiocentric myofibroblastic tumor of the penis in a child: case report and literature review

A 6 1/2-year-old boy presented with a painless, white pearly nodule on the glans penis. Wedge excision was performed and pathological examination revealed a benign-appearing, well demarcated nodule confined to the corpus spongiosum. Histological examination revealed a peculiar multinodular myofibroblastic proliferation centered around the vessels within the penis. He has done well for 9 months without evidence of recurrence. To our knowledge this is a previously undescribed lesion arising from the male genitalia.

Retrovesical leiomyoma: CT and contrast-enhanced MR imaging findings

The computed tomographic (CT) and magnetic resonance (MR) appearance of a retrovesical leiomyoma in a male patient is presented. Although leiomyomas are common lesions, the location within the retrovesical pouch is very unusual.

Giant sclerosing leiomyoma of bladder presenting as chronic renal failure

The clinical and pathologic features of a case of giant sclerosing leiomyoma of the bladder in a male Polynesian patient are reported. The presenting complication of chronic renal failure due to tumor envelopment of both ureters and consequent bilateral renal obstruction appears to be unique in the literature.

Leiomyoma of the kidney: presentation of 4 new cases and the role of computerized tomography

Renal leiomyoma is a challenging diagnostic and therapeutic condition. It is clinically similar in presentation and radiographic appearance to its malignant counterpart, leiomyosarcoma. We review 30 cases of clinically diagnosed leiomyoma of the kidney from the literature, including 4 new cases with emphasis on the computerized tomography findings. Computerized tomography may locate a renal leiomyoma serendipitously in an asymptomatic patient. If the lesion is peripheral or in the parapelvic area and a plane can be seen between the tumor and kidney a capsular tumor, such as a leiomyoma of the kidney, might be considered in addition to the more common renal cell carcinoma. Renal leiomyomas have a variable radiographic pattern from that of a pure cystic to a mixed solid/cystic to an entirely solid lesion. Renal leiomyomas usually are sharply demarcated from the surroundings. Although computerized tomography cannot distinguish a renal leiomyoma from other benign or malignant renal processes the presence of invasion can virtually eliminate this benign tumor as a diagnosis. Since a preoperative diagnosis cannot be made, management involves renal exploration and radical nephrectomy in the larger lesions with a renal-sparing operation possible in selected cases. After treatment patients have a uniformly excellent prognosis.