Inflammatory Pseudotumor (Pseudosarcoma) of the Bladder

0022-534 7/89/1413-0610$02.00/0

Vol. 141, March

THE JOURNAL OF UROLOGY

Printed in U.S.A.

Copyright © 1989 by The Williams & Wilkins Co.

INFLAMMATORY PSEUDOTUMOR (PSEUDOSARCOMA) OF THE BLADDER GEORGE L. STARK, RICHARD FEDDERSEN, BRUCE A. LOWE, CARLEEN T. BENSON, WILLIAM BLACK AND THOMAS A. BORDEN From the Departments of Surgery and Pathology, University of New Mexico School of Medicine, Albuquerque, New Mexico, and Division of Urology, Oregon Health Sciences University, Portland, Oregon

ABSTRACT

Inflammatory pseudotumor (pseudosarcoma) of the bladder is a benign proliferative lesion of the submucosal stroma easily mistaken for a malignant neoplasm clinically and histologically. The lesion was first described as a separate entity in a report of 2 patients. Three additional cases have been reported since then. We describe pseudosarcomatous bladder tumors arising in 2 adolescents. Both patients presented with sudden onset of gross painless hematuria related to large polypoid and ulcerated bladder masses found on endoscopy. Initial pathological analysis was interpreted as poorly differentiated sarcoma in both patients but subsequent reviews were consistent with a benign process resembling nodular fasciitis. Simple excision in both patients has been successful in eradicating the lesion. The findings in these 2 patients are described with a discussion of the pathophysiology and review of the literature. ( J. Ural., 141: 610-612, 1989) Sarcomatous bladder tumors can present with gross hematuria arising from exophytic and ulcerated masses. In 1985 Nochomovitz and Orenstein described 2 patients who presented with presumed sarcoma of the bladder but who demonstrated histological appearances similar to nodular fasciitis without cellular changes characteristic of malignancy. 1 Treatment consisted of simple excision and recurrence was not noted in either patient. They labeled this entity inflammatory pseudotumor. Two subsequent reports describe 3 additional patients with similar lesions. 2 • 3 We report 2 additional cases arising in adolescents initially referred for a diagnosis of sarcoma. In b0th patients simple excision was successful in eradicating the lesion. Implications in patient management are significant and an awareness of the condition may prevent the initiation of inappropriate treatment. The publication of 4 reports in the last 2 years suggests that pseudosarcomas may be more common than currently is appreciated. CASE REPORTS

Case 1. A 19-year-old Hispanic man presented with the acute onset of total gross hematuria, clot retention and sterile urine. Endoscopically, a large actively bleeding 2 x 3 cm. mass was seen in the bladder dome. Initial biopsy suggested a poorly differentiated spindle cell tumor consistent with sarcoma or anaplastic transitional cell carcinoma. Metastatic disease was not found and the patient was referred for further treatment. There was no history of pelvic trauma, operations, urinary tract infections or drug use. Tobacco use was limited to the previous 5 years and was less than 1 pack per day. Family history and physical examination were unremarkable. Laboratory studies were negative. Thickening of the bladder dome was noted on a computerized tomography (CT) scan. Review of the biopsy material indicated none of the cytological characteristics of malignancy and a diagnosis of inflammatory pseudotumor was established. Segmental excision revealed transmural involvement of the bladder wall without extension into the perivesicle tissues. The patient has been followed for more than 24 months without evidence of recurrence. Accepted for publication August 15, 1988.

Case 2. A 16-year-old Hispanic girl presented with 4 days of gross hematuria and profound anemia. Hematocrit was 22.1 and hemoglobin was 7.1. No other laboratory abnormalities were identified. Physical examination revealed an obese young girl with mild tachycardia. Excretory urography demonstrated normal upper tracts with the suggestion of a mass in the right bladder wall. Endoscopically, a 3 x 3 cm. polypoid ulcerated lesion was seen near the right trigone. Initial biopsy results were interpreted as embryonal rhabdo:rnyosarcoma, not botryoides. The patient was referred for further management. There was no history of pelvic trauma, operations, urinary tract infection, or tobacco or drug use. CT and magnetic resonance imaging (MRI) demonstrated a mass arising in the right posterior bladder wall with questionable extension into the peripelvic fat, and into the lower uterine segment and cervix (fig. 1). On review the biopsy findings were similar to case 1 and diagnosis was inflammatory pseudotumor. At exploration there was no grossly evident invasion beyond the bladder wall and the lesion was completely excised. The patient has been followed for 17 months without evidence of recurrence. PATHOLOGICAL ANALYSIS

Case 1. The operative specimen consisted of a 2 X 3 cm. portion of bladder with a thickness of 1.5 cm. The mucosal surface was flat and edematous with a 1 cm. ulcerated site where the biopsy specimens had been obtained. A poorly circumscribed mass extended beyond this, and blended imperceptibly into the underlying muscularis and fibroadipose tissue. Histological appearance was similar to the transurethral resection specimens. Both contained a cellular population of spindleshaped cells suspended in a myxoid ground substance. The nuclei were large with prominent nucleoli, an open chromatin pattern and regular nuclear membranes. Mitotic figures were common, about 1 per 10, 400X fields but never abnormal. The tumor contained moderate numbers of capillaries lined by prominent endothelium and a mixed infiltrate of lymphocytes, mast cells, neutrophils and numerous eosinophils. At the tumor periphery the spindle cells insinuated between smooth muscle cells without destroying them, with full thickness infiltration extending into the perivesicle fat. The spindle cell proliferation was clearly present in focal areas of the excised margin (fig. 2).

610

611

INFLAMMATORY PSEUDOTUMOR OF BLADDER

Case 2. The specimen contained a submucosal infiltrate of spindle cells, similar in most respects to case 1. The low power appearance was less cellular owing to a greater amount of intercellular mucoid ground substance. Mitoses were rare. Inflammatory infiltrates were sparse compared to case 1, except at the ulcerated mucosal surfaces (fig. 3). Although focal infiltration of bladder smooth muscle was present in the transurethral resection material, the abnormal spindle cells were absent from the partial cystectomy specimen. In summary, the cells in question bore cytological characteristics common to reactive and malignant proliferative processes but lacked the nuclear pleomorphism and atypical mitoses that characterize malignant mesenchymal tumors. Electron microscopic studies were not done in these cases. Case 1 was reviewed. by Dr. Lucian Nochomovitz, who confirmed the similarity of

FIG. 1. Case 2. MRI image demonstrates right posterior bladder tumor with possible infiltration through bladder wall into region of cervix and lower uterine segment.

this lesion to the cases of inflammatory pseudotumor he recently reported. 1 DISCUSSION

Inflammatory pseudotumor of the bladder was first described as a clinical entity in 1985. 1 Including our patients a total of 7 cases has been reported. In all cases the initial diagnosis was sarcoma with ablative surgery recommended for management. Clinical features of the reported cases are listed in the table. There is no apparent sex predilection and our 2 patients indicate that the lesions have appeared at any age beyond childhood. Gross hematuria is the common presenting symptom and was significant enough to cause anemia in case 2. Laboratory studies are uniformly negative. Radiological studies demonstrate a bladder wall tumor and no evidence of distant metastasis. In case 2 the radiological findings falsely indicated local invasion. Grossly, the lesions are singular broad-based exophytic tumors. These have been found at different sites in the bladder wall but none has involved the trigone. Diameter has ranged from 1.5 to 5 cm. Endoscopic appearance is that of a malignant tumor. Histologically, the lesions are similar to

FIG. 3. Case 2. High power magnification of lesion demonstrates abnormal spindle cell population similar to case 1 but less dense and suspended in loose intercellular mucoid ground substance. Two mitotic figures are seen. Reduced from X400.

FIG. 2. Case 1. A, partial cystectomy specimen shows ulcerated mucosa! surface with adherent crust (left side). Proliferation of fibroblast-like cells originates in submucosa and infiltrates widely between darker staining smooth muscle bundles of bladder wall. Reduced from X25. B, higher magnification shows abnormal spindle cells with enlarged yet rather uniform nuclei and copious cytoplasm. They are suspended in myxoid ground substance, with numerous small capillaries and mixed inflammatory infiltrates. Reduced from X200.

.,,.··1::-

612

STARK AND ASSOCIATES Reference

Nochomovitz and Orenstein'

Pt. Age-Sex

Predisposing Factor

22-M 73-F 51-F

None None None

Young and Scully'

52-F 59-M

Roth 8 ·*

32-F

None Transurethral resection of bladder tumors Urinary tract infection

Present study

19-M 16-F

None None

Ro and associates

2

Symptoms

Endoscopic Appearance

Treatment

Hematuria Hematuria Hematuria and anemia Hematuria Hematuria

5 cm. posterior bladder wall 3-5 cm. It. bladder wall 2 cm. bladder dome

Partial cystectomy Transurethral resection Partial cystectomy

4 yrs. 3 mos. 2 yrs.

4 cm. It. posterior wall 2 cm.

Transurethral resection Transurethral resection

1 yr. Not reported

1.5 cm. posterior bladder wall 2 cm. posterior bladder wall 3 cm. rt. bladder wall

Partial cystectomy

None

Partial cystectomy Partial cystectomy

24 mos. 17 mos.

Hematuria Hematuria Hematuria and anemia

Followup

* This case may represent a different etiological entity.

malignant mesenchymal tumors but careful review will fail to reveal changes specific for malignant neoplasm. 1• '1 The 7 cases bear a striking histological resemblance to nodular fasciitis, a benign mesenchymal tumor of unknown etiology. Usually found in the subcutaneous or fascial planes of the upper extremities or torso, these lesions were described first in 1955. Before 1955 these tumors were called sarcomas or fibrous histiocytomas.4 Nodular fasciitis demonstrates some of the characteristics of malignancy, such as tissue invasion, rapid growth and nuclear enlargement but growth always is selflimited and there has never been a documented recurrence or metastasis after local excision." Occasionally, these lesions will be found at various locations other than the subcutaneous tissues. s, 7 Proppe and associates described 8 cases of spindle cell nodules in the genitourinary tract developing about 5 to 12 weeks after a pelvic operation. 6 Nochomovitz and Orenstein noted many histological similarities among these trauma-associated nodules, nodular fasciitis and inflammatory pseudotumors, and postulated a histogenetic relationship. 1 In 1980 Roth described a pseudosarcomatous lesion in a 32-year-old woman with a long history of recurrent urinary tract infection. 8 The 2 patients described by Ro and associates had no history of pelvic injury and described histological findings similar to our cases except for the presence of occasional giant cells, findings not described by Nochomovitz and Orenstein. 2 Young and Scully reported 1 pseudosarcomatous bladder lesion associated with prior surgery and closely resembling the postoperative spindle cell nodules described by Proppe and associates." Fibroma, myxoid malignant histiocytoma and aggressive angiomyxoma have histological findings that are similar to pseudosarcomatous tumors but they present with different clinical courses. The inflammatory pseudotumors can arise in the presence of a chronic irritative condition or de novo in the absence of any predisposing conditions. Although slight variations in the histological patterns and in the clinical presentation occur, the condition appears to be uniformly benign and may represent a spectrum of a distinct clinical entity related to nodular fasciitis. Optimal management for these lesions is unclear because of the small number of patients identified. From the table 2 cases were treated by simple transurethral resection alone with no recurrence. The other cases were treated by segmental resec-

tions with no recurrence. Our case 1 had full thickness involvement of the bladder wall that was not obliterated by transurethral resection. Whether complete eradication is necessary is not clear. In nodular fasciitis complete excision may be difficult but not essential to prevent recurrence.° Case 1 had positive margins for abnormal spindle cells yet there has been no recurrence for more than 24 months. Management may be initial transurethral resection followed by surveillance endoscopy and biopsy to document resolution. Recognition of this benign, yet rare lesion is of significant importance to the patient who may undergo extensive surgical procedures unnecessarily. The initial appearance although alarming demonstrates important differences that distinguish the lesion as benign. The diagnosis should be considered in cases of undifferentiated sarcoma or fibrous histiocytoma of the bladder. The number of recent reports appearing in the pathology literature would indicate that inflammatory pseudotumors may be a more common entity than the paucity of cases would indicate. REFERENCES

1. Nochomovitz, L. E. and Orenstein, J. M.: Inflammatory pseudo-

2. 3.

4. 5. 6.

7. 8.

tumor of the urinary bladder-possible relationship to nodular fasciitis. Two case reports, cytologic observations, and ultrastructural observations. Amer. J. Surg. Path., 9: 366, 1985. Ro, J. Y., Ayala, A.G., Ordonez, N. G., Swanson, D. A. and Babaian, R. J.: Pseudosarcomatous fibromyxoid tumor of the urinary bladder. Amer. J. Clin. Path., 86: 583, 1986. Young, R. H. and Scully, R. E.: Pseudosarcomatous lesions of the urinary bladder, prostate gland, and urethra: a report of three cases and review of the literature. Arch. Path. Lab. Med., 111: 354, 1987. Konwaler, B. E., Keasbey, L. and Kaplan, L.: Subcutaneous pseudosarcomatous fibromatosis (fasciitis): report of 8 cases. Amer. J. Clin. Path., 25: 241, 1955. Bernstein, K. E. and Lattes, R.: Nodular (pseudosarcomatous) fasciitis, a nonrecurrent lesion: clinicopathologic study of 134 cases. Cancer, 49: 1668, 1982. Proppe, K. H., Scully, R. E. and Rosai, J.: Postoperative spindle cell nodules of the genitourinary tract resembling sarcomas: a report of eight cases. Amer. J. Surg. Path., 8: 101, 1984. Hafiz, M. A., Toker, C. and Sutula, M.: An atypical fibromyxoid tumor of the prostate. Cancer, 54: 2500, 1984. Roth, J. A.: Reactive pseudosarcomatous response in urinary bladder. Urology, 16: 635, 1980.