Sarcomatoid Carcinoma of Urinary Bladder: a Case Report.

Sarcomatoid carcinoma is an extremely rare aggressive tumor variant comprising about 0.3% of all primary tumors of the urinary bladder and carries an overall dismal prognosis. Diagnosis is important and is sometimes difficult. Immunohistochemistry plays an important role in establishing diagnosis. We report a case with sarcomatoid variant of bladder urothelial carcinoma and review the pathologic features. A 65-year-old male on evaluation of long standing obstructive voiding symptoms and intermittent hematuria found to have a bladder mass. Magnetic resonance urography revealed a 35 × 45 mm mass at dome of urinary bladder with perivesical fat infiltration. He underwent transurethral resection and histopathology revealed pT1 high-grade malignant spindle cell tumor. He underwent radical cystoprostatectomy with bilateral extended pelvic lymphadenectomy with EPLND with ileal conduit urine diversion. Histopathology revealed high-grade muscle invasive spindle cell tumor. The diagnosis was uncertain and two differential diagnosis were kept, sarcomatoid carcinoma and pleomorphic sarcoma. Finally, IHC confirmed the final diagnosis of sarcomatoid carcinoma as it was positive for cytokeratin, CK - 8/18, GATA 3. All lymph nodes were negative for metastasis (pT2, N0, Mx). Recognition of the rare variants of the urinary bladder urothelial tumors is imperative as it is affects the overall management and hence prognosis. Immunohistochemistry plays a paramount role in establishing the diagnosis.