[Inflammatory myofibroblastic tumor of bladder: a clinicopathologic study of five cases].
OBJECTIVE
To study the clinicopathologic features, diagnosis and differential diagnosis of inflammatory myofibroblastic tumor of the urinary bladder.


METHODS
Excisional specimens from 5 cases of vesical inflammatory myofibroblastic tumor were studied by light microscopy and immunohistochemistry (EnVision). The clinical data were also analyzed.


RESULTS
Among the 5 patients studied, 3 were males and 2 were females. The age of the patients ranged from 10 to 53 years (mean age = 35 years). The most common clinical presentation was micturition pain and hematuria. Three cases were located at the dome of the urinary bladder and the remaining 2 cases were found in the left lateral wall. Histologically, the tumor varied from myxoid to highly cellular. The tumor cells were spindle to stellate in shape, widely separated or showed a compact fascicular pattern. There were often associated with mixed inflammatory infiltrates and an irregular meshwork of small dilated vessels. Immunohistochemical study showed that the tumor cells expressed AE1/AE3 (5/5), vimentin (5/5), smooth muscle actin (5/5), calponin (5/5), caldesmon (3/5), desmin (4/5) and anaplastic lymphoma kinase protein (4/5). Follow-up data were available in 4 patients and none had local recurrence or died of this disease.


CONCLUSIONS
Inflammatory myofibroblastic tumour of urinary bladder is a rarely encountered but distinctive neoplasm with intermediate malignant potential.
Sun
Ke
K
Department of Pathology, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China.
Wang
Zhao-ming
ZM
Xu
Lin-jie
LJ
Teng
Xiao-dong
XD
Yao
Hong-tian
HT
Ren
Guo-ping
GP
D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000077548:Anaplastic Lymphoma Kinase; D001457:Anion Exchange Protein 1, Erythrocyte / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002648:Child; D015653:Cystectomy / Q000379:methods; D003937:Diagnosis, Differential; D005260:Female; D005354:Fibrosarcoma / Q000473:pathology; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000473:pathology; D007890:Leiomyosarcoma / Q000473:pathology; D008297:Male; D008840:Microfilament Proteins / Q000378:metabolism; D008875:Middle Aged; D009379:Neoplasms, Muscle Tissue / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases; D012208:Rhabdomyosarcoma / Q000473:pathology; D015996:Survival Rate; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D014746:Vimentin / Q000378:metabolism; D000096985:Calponins
D000199:Actins; D000077548:Anaplastic Lymphoma Kinase; D001457:Anion Exchange Protein 1, Erythrocyte; D002135:Calcium-Binding Proteins; D008840:Microfilament Proteins; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D014746:Vimentin; D000096985:Calponins; C541116:ACTA2 protein, human; C000626173:ALK protein, human