Lucia Gala Solana
Introduction Inflammatory myofibroblastic tumor (IMT) is an unusual intermediate soft tissue tumor, rarely occurring in the urinary bladder. IMT has a relatively good prognosis and is considered to be a tumor with intermediate biologic potential because of its low risk of distant metastases. Clinical findings A 42-year old man with factor VII deficiency, non smoker, was evaluated by Internal Medicine because of microhematuria, severe anemia, frequency–dysuria syndrome and bladder outlet obstruction. Diagnosis and treatment The patient was referred to urological evaluation for the finding of a large bladder mass of 8 centimeters, without distant metastases on CT-scan. Abdominal MRI scan was performed, finding no evidence of extravesical mass and a tumor bed on left lateral bladder wall about 3 centimeters (Figure 1). Figure 1. Abdominal MRI scan showed a single giant bladder mass, with no signs of extravesical mass. Patient underwent to transurethral resection, that was incompletely performed, requiring the use of NovoSeven®, a recombinant human coagulation Factor VIIa (rFVIIa) and several units of red blood cells. Three weeks later, an additional “second – look” was performed, likewise incomplete. Pathology report revealed an inflammatory myofibroblastic tumor. Histological examination (hematoxylin-eosin staining) showed spindle cell proliferation with inflammatory cells on a myxoid stroma. The results of immunohistochemistry examination showed: Vimentin (+), CD68 (+), Desmin (+), Caldesmon (+) and ALK (+), AE1/AE3 (-), CK34β12 (-), actin (-), Myogenin (-), p53 (-), S-100 (-), EMA (-), BCL2 (-), DOG1 (-) and CD117 (-). After discussing the treatment plan with the patient and his family, a decision to do a conservative management with a partial laparoscopic cystectomy was made. Final pathology report was an inflammatory myofibroblastic bladder tumor with muscle layer infiltration (pT2b). Conclusions Also called inflammatory pseudotumor, first case report of an inflammatory myofibroblastic tumor of the urinary bladder was made in 1980. Most patients are young (mean age of 38.9). Hematuria is the commonest clinical manifestation. It is characterized by atypical spindle cell proliferation and inflammatory cell infiltrates primarily involving lymphocytes and plasma cells. Most frequently found on lung. IMT in the urinary bladder is unusual. Recent reports have indicated that ALK (anaplastic lymphoma kinase) was overexpressed in a substantial proportion of IMT. A positive finding of ALK in up to 87.5% of IMT can be useful for the differentiation of IMT from other spindle cell tumors. Surgical resection is the treatment of choice. Most patients goes to TURB, but partial and radical cystectomy can be considered. IMT of the bladder have a local tumor recurrence rate after surgery of 4%. Complete surgical resection is the most important factor to avoid local recurrence. IMT tumors are classified as intermediate (rarely metastasizing) tumors according to the WHO classification of soft tissue tumors.