Renal inflammatory myofibroblastic tumor - a new case report.

Renal inflammatory pseudotumor is uncommon, benign tumor that has been classified into separate group but there is a risk that this lesion could be misdiagnosed. The aim of this work is to report a new case of 57-years-old man presented in our hospital with hematuria, minimal grade fever and right flank pain. Magnetic resonance imaging (MRI) and sonography revealed a tumor of the right mediorenal parenchyma, 2.5 cm in diameter. The patient underwent right nephroureterectomy under the diagnosis of renal cell carcinoma. Macroscopically examination carried out on the removed kidney showed a 2/2/1.5 cm yellowish, gelatinous, well circumscribed, mediorenal and pericaliceal mass. Fragments of the tumor were fixed in 10% formaldehyde, included in paraffin, and the sections were stained with HE, VG and immunohistochemically with vimentin (VIM), MNF116, SyN, smooth muscle actin (ACT), desmin, CD68, S100, HMB45, and CD117. The histological examination revealed a compact spindle cell proliferation, a hypocellular fibrous area in an edematous myxoid background infiltrated by small lymphocytes, histiocytes, some plasma cells and small bone area. The spindle cells were diffuse positive for VIM, ACT, CD68 and negative for desmin, MNF116, SyN, S100, HMB45, and CD117. The pathologic diagnosis was renal inflammatory pseudotumor, raising the problem of differential diagnosis, as the clinical and imagistic aspects are similar to those of a renal carcinoma and the problem in establishing a preoperative correct diagnosis.

Small cell carcinoma of the urinary bladder--a new case report.

Primary pure small cell carcinoma of the urinary bladder is an extremely rare and highly aggressive tumor with an average five-year survival rate of less than 10% as cited by multiple case reports. It accounts for about 0.5-1% of all bladder tumors. We present the case of a 44-years-old man, smoker (10 cigarettes/day) hospitalized in the Department of Urology, from the "Prof. dr. Th. Burghele" Hospital, Bucharest, for one month intermittent hematuria. Ultrasonography showed a sessile tumoral mass, sized 37/30mm. Transurethral resection of the tumor mass was performed and tissue fragments were sent to the pathologic lab to establish the histologic type, the degree of differentiation and invasion. Fragments of the tumor were fixed in 10% formaldehyde, paraffin embedded and processed as standard technique; the sections were stained with HE, VG and immunohistochemically with: CROMO, EMA, NSE, CD56, NK1, p53 and betaHCG. The microscopic examination reveled a tumor proliferation composed of two distinct components: extensive small cells areas and foci of typical low grade (G2) papillary urothelial carcinoma. The small cell are uniformly, round, with increased nucleo-cytoplasmic ratio, eosinophyl cytoplasm, hyperchromatic nuclei, finely granular chromatin and inconspicuous nucleoli. Immunohistochemical stains showed diffuse positive staining of the small cell component for CROMO, EMA, NSE, CD56, NK1 and urothelial carcinoma component stained focally for betaHCG. The rate of cell proliferation was increased (p53 - 80% positive reaction). Conclusions. A diagnosis of small cell carcinoma coexisting with low-grade urothelial carcinoma was established. Because of aggressive behavior and distinct treatment, the pathologist should watch out for the presence of small cell carcinoma component.