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Epithelioid Leiomyoma of the Bladder: An Unusual Cause of Voiding Symptoms
CASE REPORT
EPITHELIOID LEIOMYOMA OF THE BLADDER: AN UNUSUAL CAUSE OF VOIDING SYMPTOMS DEANNA SOLOWAY, MICHAEL A. SIMON, CLARA MILIKOWSKI,
AND
MARK S. SOLOWAY
ABSTRACT Epithelioid leiomyoma of the bladder is a rare benign neoplasm. A 63-year-old woman with a 2-year history of frequency and urgency was found to have a bladder mass on intravenous urography and subsequent cystoscopy. The mass was removed endoscopically. The patient’s symptoms resolved. UROLOGY 51: 1037–1039, 1998. © 1998, Elsevier Science Inc. All rights reserved.
B
enign mesothelial tumors of the bladder make up only 1% to 5% of all bladder neoplasms, with leiomyomas representing the largest subgroup of these benign tumors. In 1953, Campbell and Gislason1 reviewed 193 cases of leiomyoma reported up to that time. The symptoms of these tumors vary and may include irritative symptoms (burning, dysuria, urgency), obstructive symptoms, or hematuria. Some masses have been noted, on the other hand, to be asymptomatic and are only discovered by radiographic tests. The patient described here presented with a long history of irritative symptoms. An endoscopic examination confirmed the presence of a bladder tumor. CASE REPORT A 63-year-old woman presented in April 1995 with symptoms of frequency and urgency that had been present for approximately 2 years. She denied hematuria and did not have a history of urinary tract infection. Her initial evaluation included a urodynamic study that demonstrated normal capacity. The patient was treated with a variety of medications, including an anticholinergic agent, with minimal relief of symptoms. In January 1997, the patient underwent an intravenous urogram (IVU) that showed the kidneys to be normal in size, shape, and configuration (Fig. 1). The ureters were identified following a normal
From the Departments of Urology and Pathology, University of Miami School of Medicine, Miami, Florida Reprint requests: Mark S. Soloway, M.D., University of Miami School of Medicine, Department of Urology, Post Office Box 016960 (M814), Miami, FL 33101 Submitted: September 18, 1997, accepted (with revisions): November 21, 1997 © 1998, ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED
course in the urinary bladder. A well-defined, ovalshaped filling defect measuring 6.0 3 3.5 cm was observed protruding into the bladder lumen, which appeared to be associated with the distal right ureter. It was believed at that time to be most likely a ureterocele, although a solitary papillary neoplasm could not be excluded. The patient subsequently underwent a voiding cystourethrogram that again delineated the mass within the urinary bladder to the right of midline. There was no vesicoureteral reflux. Urinalysis was normal. Laboratory studies were performed, including a serum chemistry evaluation, complete blood count, and liver function studies, all of which were normal. A urine culture exhibited no growth. Residual urine studies were performed on several occasions with the highest postvoid residual being 45 cc. The patient was taken to the operating room where cystoscopy was performed. A large solid neoplasm on a stalk was noted just inferior to the right ureteral orifice (Fig. 2). The stalk was small, and the initial portion of the procedure involved dividing the stalk with the angled or bladder wall loop electrode. This left a free-floating 6.0 3 3.5-cm mass in the bladder. The urethra was dilated and a Randall stone forceps was introduced. With the combination of a nasal speculum, used to dilate the urethral orifice, and the Randall forceps, the lesion was removed in two pieces. PATHOLOGIC REPORT The surgical specimen consisted of multiple pieces of pale yellow, soft rubbery tissue measuring 4.0 3 3.0 3 1.4 cm in aggregate (Fig. 3). The tissue was submitted in its entirety for histologic 0090-4295/98/$19.00 PII S0090-4295(98)00016-8 1037
FIGURE 1. (A) Intravenous urogram demonstrating filling defect in bladder; (B) filling defect in bladder.
FIGURE 3.
FIGURE 2. Endoscopic appearance of stalk of epithelioid leiomyoma.
examination. The histologic data revealed a uniformly cellular neoplasm. The tumor was composed of sheets of round and ovoid cells. Cytoplasm was abundant and faintly eosinophilic and fibrillar or clear. Nuclei were centrally located and round to oval with vesicular chromatin. Mitotic figures and atypia were not present. Cystitis cystica was focally present in the urothelial layer and numerous mast cells were present in the submucosa. Immunocytochemical analyses showed strong positivity for desmin (Fig. 4). Smooth muscle actin, S-100 protein, macro1038
Excised leiomyoma.
phage Ki, and keratin were negative. The combination of the histomorphology and the immunoreactivity of the tumor for desmin supports a diagnosis of epithelioid leiomyoma. COMMENT The differential diagnosis of benign bladder tumors includes (a) myomas, which include fibromyomas, leiomyomas, and rhabdomyomas; (b) fibromas; (c) angiomas; (d) myxomas; and (e) osteomas. Leiomyoma, the most common single histologic type of benign bladder tumor, shows no predilection for gender or age.1 This statement was contested by Goluboff et al.2 in 1994 when they observed a higher incidence of leiomyomata in women in their third to fifth decade of life with a UROLOGY 51 (6), 1998
FIGURE 4. Immunoperoxidase staining is uniformly and strongly positive for desmin.
mean size of 5.8 cm2. These lesions may be categorized as endovesical, extravesical, or intramural. Endovesical masses have been recognized as the most common subtype (63%) possibly due to its characteristic bulging into the bladder compartment causing irritative symptoms that force the patient to seek medical treatment.2 The remainder include extravesical and intramural masses, which have been noted to occur with a frequency of 30% and 7%, respectively. The history often encompasses some degree of urinary symptomatology. In February 1994, Goluboff et al.2 reviewed all reported cases of leiomyoma of the bladder in the English literature since 1970. They indicated that obstructive symptoms were the most frequent presenting patient complaint (49%). Of the remaining patients, 38% presented with irritative voiding symptoms, 11% with hematuria, and 19% were asymptomatic.2 Knoll et al.3 indicated that irritative symptoms were the most frequent presenting symptom. After a comprehensive history, a complete physical examination is imperative, because it has been noted that a palpable lesion is encountered in 57% of women who undergo bimanual examination.2 The next step in the examination usually includes an IVU or cystourethrogram, which identifies a smooth filling defect in the bladder. Abdominal ultrasound may be helpful in differentiating a cystic from a solid lesion. Fernandez and Dehesa4 investigated the various radiographic measures used in demonstrating these benign tumors to determine which method was the most fruitful for the physician preoperatively. They noted computed tomography scan to be beneficial for precisely locating the tumor but inadequate for identifying its relationship to the adjacent bladder mucosa or vaginal wall due to its fixed axial plane. They advocated transvaginal ultrasound, which they perceived as producing better definition of the mass. Leiomyomas of the bladUROLOGY 51 (6), 1998
der are demonstrated sonographically as solid smooth-walled lesions with many internal echoes and with an underlying homogeneous texture of medium echogenicity.2 Cystoscopically, these tumors are easily visualized and are covered with normal bladder mucosa. Histologically, leiomyoma of the bladder may be clearly differentiated from leiomyosarcoma. Leiomyomas appear as whitish-gray round to ovoid nodules with spiral appearance of smooth muscle fibers. They are firm and rubbery in consistency. There are usually less than two mitotic figures per high powered field.2 Like its benign counterpart, leiomyosarcoma may have little mitotic activity microscopically but it usually has a large quantity of myxoid intracellular material and invades the muscularis propria. There are no reports of malignant degeneration of leiomyoma. The treatment of these rare mesothelial bladder tumors is determined primarily by their size and anatomic location. In Goluboff’s review of the literature, 62% were treated by open resection, whereas 30% were removed by transurethral resection. The small endovesical tumors can be resected transurethrally; only 18% have necessitated reoperation due to incomplete initial resection. Of the 62% who underwent open resection, all had large endovesical tumors, extravascular tumors, or intramural lesions, and none required a second procedure.2 The low reoperation rate, absence of recurrence, and excellent prognosis of leiomyoma after surgical excision leaves the patient asymptomatic. The pathophysiology of leiomyoma of the bladder is unclear. There are four major theories that have been proposed: (a) it is an inflammatory resection of the bladder wall to an infection of the bladder musculature; (b) it is a metaplastic reaction around the perivascular walls from vascular inflammation of the bladder; (c) it is neoplasm controlled by hormonal influences; and (d) it is dysontogenesis—the result of embryologic rest within the bladder wall developing into a smooth muscle tumor.2 Although the cause remains a mystery, the diagnostic examination and surgical management are straightforward. REFERENCES 1. Campbell EW, and Gislason GJ: Benign mesothelial tumors of the urinary bladder: review of literature and a report of a case of leiomyoma. J Urol 70: 733–742, 1953. 2. Goluboff ET, O’Toole K, and Sawczuk IS: Leiomyoma of the bladder: report of case and review of the literature. Urology 43: 238 –241, 1994. 3. Knoll LD, Segura JW, and Scheithauter BW: Leiomyoma of the bladder. J Urol 136: 906 –908, 1986. 4. Fernandez A, and Dehesa TM: Leiomyoma of the urinary bladder floor: diagnosis by transvaginal ultrasound. Urol Int 48: 99 –101, 1992. 1039
EPITHELIOID LEIOMYOMA OF THE BLADDER: AN UNUSUAL CAUSE OF VOIDING SYMPTOMS DEANNA SOLOWAY, MICHAEL A. SIMON, CLARA MILIKOWSKI,
AND
MARK S. SOLOWAY
ABSTRACT Epithelioid leiomyoma of the bladder is a rare benign neoplasm. A 63-year-old woman with a 2-year history of frequency and urgency was found to have a bladder mass on intravenous urography and subsequent cystoscopy. The mass was removed endoscopically. The patient’s symptoms resolved. UROLOGY 51: 1037–1039, 1998. © 1998, Elsevier Science Inc. All rights reserved.
B
enign mesothelial tumors of the bladder make up only 1% to 5% of all bladder neoplasms, with leiomyomas representing the largest subgroup of these benign tumors. In 1953, Campbell and Gislason1 reviewed 193 cases of leiomyoma reported up to that time. The symptoms of these tumors vary and may include irritative symptoms (burning, dysuria, urgency), obstructive symptoms, or hematuria. Some masses have been noted, on the other hand, to be asymptomatic and are only discovered by radiographic tests. The patient described here presented with a long history of irritative symptoms. An endoscopic examination confirmed the presence of a bladder tumor. CASE REPORT A 63-year-old woman presented in April 1995 with symptoms of frequency and urgency that had been present for approximately 2 years. She denied hematuria and did not have a history of urinary tract infection. Her initial evaluation included a urodynamic study that demonstrated normal capacity. The patient was treated with a variety of medications, including an anticholinergic agent, with minimal relief of symptoms. In January 1997, the patient underwent an intravenous urogram (IVU) that showed the kidneys to be normal in size, shape, and configuration (Fig. 1). The ureters were identified following a normal
From the Departments of Urology and Pathology, University of Miami School of Medicine, Miami, Florida Reprint requests: Mark S. Soloway, M.D., University of Miami School of Medicine, Department of Urology, Post Office Box 016960 (M814), Miami, FL 33101 Submitted: September 18, 1997, accepted (with revisions): November 21, 1997 © 1998, ELSEVIER SCIENCE INC. ALL RIGHTS RESERVED
course in the urinary bladder. A well-defined, ovalshaped filling defect measuring 6.0 3 3.5 cm was observed protruding into the bladder lumen, which appeared to be associated with the distal right ureter. It was believed at that time to be most likely a ureterocele, although a solitary papillary neoplasm could not be excluded. The patient subsequently underwent a voiding cystourethrogram that again delineated the mass within the urinary bladder to the right of midline. There was no vesicoureteral reflux. Urinalysis was normal. Laboratory studies were performed, including a serum chemistry evaluation, complete blood count, and liver function studies, all of which were normal. A urine culture exhibited no growth. Residual urine studies were performed on several occasions with the highest postvoid residual being 45 cc. The patient was taken to the operating room where cystoscopy was performed. A large solid neoplasm on a stalk was noted just inferior to the right ureteral orifice (Fig. 2). The stalk was small, and the initial portion of the procedure involved dividing the stalk with the angled or bladder wall loop electrode. This left a free-floating 6.0 3 3.5-cm mass in the bladder. The urethra was dilated and a Randall stone forceps was introduced. With the combination of a nasal speculum, used to dilate the urethral orifice, and the Randall forceps, the lesion was removed in two pieces. PATHOLOGIC REPORT The surgical specimen consisted of multiple pieces of pale yellow, soft rubbery tissue measuring 4.0 3 3.0 3 1.4 cm in aggregate (Fig. 3). The tissue was submitted in its entirety for histologic 0090-4295/98/$19.00 PII S0090-4295(98)00016-8 1037
FIGURE 1. (A) Intravenous urogram demonstrating filling defect in bladder; (B) filling defect in bladder.
FIGURE 3.
FIGURE 2. Endoscopic appearance of stalk of epithelioid leiomyoma.
examination. The histologic data revealed a uniformly cellular neoplasm. The tumor was composed of sheets of round and ovoid cells. Cytoplasm was abundant and faintly eosinophilic and fibrillar or clear. Nuclei were centrally located and round to oval with vesicular chromatin. Mitotic figures and atypia were not present. Cystitis cystica was focally present in the urothelial layer and numerous mast cells were present in the submucosa. Immunocytochemical analyses showed strong positivity for desmin (Fig. 4). Smooth muscle actin, S-100 protein, macro1038
Excised leiomyoma.
phage Ki, and keratin were negative. The combination of the histomorphology and the immunoreactivity of the tumor for desmin supports a diagnosis of epithelioid leiomyoma. COMMENT The differential diagnosis of benign bladder tumors includes (a) myomas, which include fibromyomas, leiomyomas, and rhabdomyomas; (b) fibromas; (c) angiomas; (d) myxomas; and (e) osteomas. Leiomyoma, the most common single histologic type of benign bladder tumor, shows no predilection for gender or age.1 This statement was contested by Goluboff et al.2 in 1994 when they observed a higher incidence of leiomyomata in women in their third to fifth decade of life with a UROLOGY 51 (6), 1998
FIGURE 4. Immunoperoxidase staining is uniformly and strongly positive for desmin.
mean size of 5.8 cm2. These lesions may be categorized as endovesical, extravesical, or intramural. Endovesical masses have been recognized as the most common subtype (63%) possibly due to its characteristic bulging into the bladder compartment causing irritative symptoms that force the patient to seek medical treatment.2 The remainder include extravesical and intramural masses, which have been noted to occur with a frequency of 30% and 7%, respectively. The history often encompasses some degree of urinary symptomatology. In February 1994, Goluboff et al.2 reviewed all reported cases of leiomyoma of the bladder in the English literature since 1970. They indicated that obstructive symptoms were the most frequent presenting patient complaint (49%). Of the remaining patients, 38% presented with irritative voiding symptoms, 11% with hematuria, and 19% were asymptomatic.2 Knoll et al.3 indicated that irritative symptoms were the most frequent presenting symptom. After a comprehensive history, a complete physical examination is imperative, because it has been noted that a palpable lesion is encountered in 57% of women who undergo bimanual examination.2 The next step in the examination usually includes an IVU or cystourethrogram, which identifies a smooth filling defect in the bladder. Abdominal ultrasound may be helpful in differentiating a cystic from a solid lesion. Fernandez and Dehesa4 investigated the various radiographic measures used in demonstrating these benign tumors to determine which method was the most fruitful for the physician preoperatively. They noted computed tomography scan to be beneficial for precisely locating the tumor but inadequate for identifying its relationship to the adjacent bladder mucosa or vaginal wall due to its fixed axial plane. They advocated transvaginal ultrasound, which they perceived as producing better definition of the mass. Leiomyomas of the bladUROLOGY 51 (6), 1998
der are demonstrated sonographically as solid smooth-walled lesions with many internal echoes and with an underlying homogeneous texture of medium echogenicity.2 Cystoscopically, these tumors are easily visualized and are covered with normal bladder mucosa. Histologically, leiomyoma of the bladder may be clearly differentiated from leiomyosarcoma. Leiomyomas appear as whitish-gray round to ovoid nodules with spiral appearance of smooth muscle fibers. They are firm and rubbery in consistency. There are usually less than two mitotic figures per high powered field.2 Like its benign counterpart, leiomyosarcoma may have little mitotic activity microscopically but it usually has a large quantity of myxoid intracellular material and invades the muscularis propria. There are no reports of malignant degeneration of leiomyoma. The treatment of these rare mesothelial bladder tumors is determined primarily by their size and anatomic location. In Goluboff’s review of the literature, 62% were treated by open resection, whereas 30% were removed by transurethral resection. The small endovesical tumors can be resected transurethrally; only 18% have necessitated reoperation due to incomplete initial resection. Of the 62% who underwent open resection, all had large endovesical tumors, extravascular tumors, or intramural lesions, and none required a second procedure.2 The low reoperation rate, absence of recurrence, and excellent prognosis of leiomyoma after surgical excision leaves the patient asymptomatic. The pathophysiology of leiomyoma of the bladder is unclear. There are four major theories that have been proposed: (a) it is an inflammatory resection of the bladder wall to an infection of the bladder musculature; (b) it is a metaplastic reaction around the perivascular walls from vascular inflammation of the bladder; (c) it is neoplasm controlled by hormonal influences; and (d) it is dysontogenesis—the result of embryologic rest within the bladder wall developing into a smooth muscle tumor.2 Although the cause remains a mystery, the diagnostic examination and surgical management are straightforward. REFERENCES 1. Campbell EW, and Gislason GJ: Benign mesothelial tumors of the urinary bladder: review of literature and a report of a case of leiomyoma. J Urol 70: 733–742, 1953. 2. Goluboff ET, O’Toole K, and Sawczuk IS: Leiomyoma of the bladder: report of case and review of the literature. Urology 43: 238 –241, 1994. 3. Knoll LD, Segura JW, and Scheithauter BW: Leiomyoma of the bladder. J Urol 136: 906 –908, 1986. 4. Fernandez A, and Dehesa TM: Leiomyoma of the urinary bladder floor: diagnosis by transvaginal ultrasound. Urol Int 48: 99 –101, 1992. 1039