[P-32] Inflammatory myofibroblastic tumour in the urinary bladder

Nia Nuraeni1, Bethy Suryawati Hernowo1 and Vita Indriasari2

  1. Anatomical Pathology Department, Faculty of Medicine, Universitas Padjadjaran / Dr Hasan Sadikin General Hospital, Bandung, Indonesia
  2. Paediatric Surgery Department, Faculty of Medicine, Universitas Padjadjaran / Dr Hasan Sadikin General Hospital, Bandung, Indonesia

 

Background: An inflammatory myofibroblastic tumour (IMT) rarely occurs in the urinary bladder. IMT is a distinctive neoplasm composed of myofibroblastic and fibroblastic spindle cells. It also has inflammatory infiltration of plasma cells, lymphocytes and eosinophils. It is important to distinguish this tumour from other malignant spindle cell tumours.

Case Presentation: A 7-year-old girl presented with a 1.5-month history of gross haematuria. Computed tomography revealed a solitary mass tumour, measuring 6.1 x 8 x 9.5 cm at the wall of the bladder. Intraoperative finding showed a large solid bladder mass with smooth surface. Histopathology result was consistent with the IMT. The bladder tissue was widely infiltrated by spindle cells with fascicular pattern There was a myxoid stroma with infiltration of inflammatory cells. Mitotic activity was numerous, with no atypical mitotic figures were identified. Immunohistochemistry revealed focally positive for smooth muscle actin and desmin and negative for myogenin, myod1 and ALK.

Discussion and Conclusion: Clinically and radiologically, IMT of the urinary bladder is indistinguishable from other entities. It has a broad differential diagnosis ranging from reactive to malignant neoplastic lesions, including rhabdomyosarcoma, or sarcomatoid urothelial carcinoma. IMT occurs mostly in children and young adults. The final and definitive diagnosis can be only made by histopathology and immunochemistry. In a recent systematic review, the ALK is positive in 65% of cases, but there are no significant differences between ALK positive and negative in IMT of the bladder. In conclusion, the tumour was diagnosed as an IMT.