Scand J Urol Nephrol27: 127-128, 1993

A PSEUDOTUMOUR OF THE BLADDER Case Report

Biilent Celasun,’ Bedreddin Seqkiq2 Cetin Harmankaya,2 Yiiksel Pabu$qu3 and Rifki Finci’

From the Departments of’ Pathology, ’Urology, and ’Radiology, Giilhane Military Medical Academy, Etlik, 0601S Ankara, Turkey

(Submitted September 20, 1991. Accepted for publication May 29, 1992)

Abstract. A case of pseudotumour involving the blad- der is presented. The differential diagnostic impor- tance of the lesion is stressed. Key words: bladder pseudotumour, pseudosarcoma.

Inflammatory pseudotumour of the bladder is a rare lesion. Its clinical, radiological and histo- logical features can imitate those of tumours, hence the name of the lesion. We report a typi- cal case which had originally been diagnosed as sarcoma.

CASE REPORT A 21-year-old male presented with a recurrent pain- less haematuria which was shown to be unassociated with urinary tract infection. The patient mentioned having a similar attack three years ago. During that episode a bladder biopsy was done elsewhere and reported as “spindle cell sarcoma”; the patient re- fused treatment.

Cystoscopy showed a 3 ~ 2 x 2 cm irregular mass involving the left anterior wall and protruding into the cavity. On CT scanning the lesion measured 4.2 cm, extending anteriorly, sparing perivesical fat (Fig. 1 ).

Histological examination of a transurethral speci- men and review of the original biopsies showed fea- tures identical to those reported previously as inflam- matory pseudotumour ( I ) . The characteristic features were surface ulceration overlying an oedematous, partially myxoid and collagenous tissue containing capillaries and fibroblast-like cells with large nuclei and fibrillary cytoplasm (Fig. 2 ) which was probably responsible for the initial misdiagnosis of sarcoma. Dystrophic calcifications. not reported previously, and plasma cells were also noted. Mitotic activity was low. Immunohistochemical evaluation showed im- munoreaction to vimentin (Immunon V3250) by the lesional cells but not to cytokeratin (Immunon K3350) or epithelial membrane antigen (Immunon E 1470).

A partial cystectomy was done.

COMMENTS AND CONCLUSION

Inflammatory pseudotumour of the bladder is a relatively recently described entity with only a few reported cases (1 , 2, 3). Increased recogni- tion of this lesion is warranted as all the cases reported to date have either been misdiagnosed as sarcoma or closely resembled one.

Clinically, the lesion is a bladder mass caus- ing painless haematuria in an adult ‘without’ any antecedent bladder instrumentation or sur- gery. Radiological studies enhance the impres- sion of malignancy.

Histologically, the lesion resembles nodular fasciitis of soft tissues ( l ) , a self-limited reactive process. Another histologically similar lesion developing following bladder instrumentation, the postoperative spindle cell nodule, expresses immunohistochemical positivity for cytokera- tin and is probably different histogenetically (4, 5). Although the exact origin of the inflamma- tory pseudotumour is unkown, its mesenchy-

Fig. 1. CT image of the bladder mass.

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Fig. 2. Histological appearance of the lesion showing spindle-celled proliferation. H & E, x 170.

ma1 nature and indolent behaviour has been well-established (1, 2, 4).

Conservative treatment measures like TUR have been suggested (2, 3). Our patient appar- ently had the lesion for at least three years and remained asymptomatic during the 24-month postoperative period.

Increased awareness to this entity should pre- vent misdiagnosis in most cases.

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REFERENCES Nochomowitz LE, Orenstein JM. Inflammatory pseudotumor of the urinary bladder; possible rela- tionship to nodular fasciitis. Am J Surg Pathol

Ro JY, Ayala AG, Ordoiiez NG, Swanson DY, Babaian RJ. Pseudosarcomatous fibromyxoid tu- mor of the urinary bladder. Am J Clin Pathol

Stark GL, Feddersen L. Lowe BA, Benson CT, Black W, Borden TA. Inflammatory pseudotumor (pseudosarcoma) of bladder. J Urol 1989; 141: 6 10-6 1 2. Wick MR, Young RH, Mills SE, Manivel JS, Dehner LP. Immunohistochemical features of postoperative spindle cell nodules and inflamma- tory pseudotumors of genitourinary tract. Lab In- vest 1988; 58: 107A (abstract). Proppe KH, Scully RE, Rosai J. Postoperative spindle cell tumors of genitourinary tract resem- bling sarcomas. A report of eight cases. Am J Surg Pathol 1984; 8: 101-108.

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1986; 86: 583-590.

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