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Int J Clin Exp Pathol 2013;6(8):1671-1676

Case Report
Sarcomatoid carcinoma with small cell carcinoma component of the urinary bladder: a
case report with review of the literature

Mitsuaki Ishida, Muneo Iwai, Keiko Yoshida, Akiko Kagotani, Hidetoshi Okabe

Department of Clinical Laboratory Medicine and Division of Diagnostic Pathology, Shiga University of Medical Science, Shiga, Japan

Received June 11, 2013; Accepted July 8, 2013; Epub July 15, 2013; Published August 1, 2013

Abstract: Sarcomatoid carcinoma of the urinary bladder is an uncommon neoplasm characterized histopathologically by the presence of
malignant spindle cell and epithelial components. Albeit extremely rare, sarcomatoid carcinoma with small cell carcinoma has been reported.
Herein, we describe an additional case of sarcomatoid carcinoma with small cell carcinoma and squamous cell carcinoma of the urinary
bladder and review the clinicopathological features of this type of tumor. An 82-year-old Japanese male presented with hematuria. Computed
tomography demonstrated a large tumor in the urinary bladder. Histopathological study of the resected urinary bladder tumor showed that
approximately 80% of the tumor was comprised of small cell carcinoma, and the remaining components were spindle cell proliferation
(approximately 15%) and squamous cell carcinoma (5%). Both the spindle cell and squamous cell carcinoma components were intermingled
with nests of the small cell carcinoma. This is the fifth documented case of sarcomatoid carcinoma with small cell carcinoma of the urinary
bladder. Our review of the clinicopathological features of this type of tumor revealed that: i) elderly males are mainly affected, ii) the most
common chief complaint is hematuria, iii) the epithelial component may include urothelial carcinoma, adenocarcinoma, and/or squamous cell
carcinoma, and iv) the sarcomatous component is composed of spindle cell proliferation. The histogenesis of this type of tumor remains a
matter of controversy. However, recent molecular analyses demonstrated a monoclonal origin of both components. This theory can account for
the various types of carcinomatous components in this tumor as seen in the present case. (IJCEP1306009).

Keywords: Carcinosarcoma, small cell carcinoma, urinary bladder

Address correspondence to: Dr. Mitsuaki Ishida, Department of Clinical Laboratory Medicine and Division of Diagnostic Pathology, Shiga
University of Medical Science, Tsukinowa-cho, Seta, Otsu, Shiga, 520-2192, Japan. Tel: +81-77-548-2603; Fax: +81-77-548-2407; E-mail:
mitsuaki@belle.shiga-med.ac.jp