Ishida Mitsuaki, Iwai Muneo, Yoshida Keiko, Kagotani Akiko, Okabe Hidetoshi
Department of Clinical Laboratory Medicine and Division of Diagnostic Pathology, Shiga University of Medical Science, Otsu, Shiga, Japan.
Int J Clin Exp Pathol. 2013 Jul 15;6(8):1671-6. Print 2013.
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.
膀胱肉瘤样癌是一种罕见的肿瘤，其组织病理学特征为存在恶性梭形细胞和上皮成分。尽管极为罕见，但已有膀胱肉瘤样癌合并小细胞癌的报道。在此，我们描述了一例膀胱肉瘤样癌合并小细胞癌及鳞状细胞癌的病例，并回顾了该类型肿瘤的临床病理特征。一名82岁的日本男性因血尿就诊。计算机断层扫描显示膀胱内有一个大肿瘤。对切除的膀胱肿瘤进行组织病理学研究发现，约80%的肿瘤由小细胞癌组成，其余成分包括梭形细胞增生（约15%）和鳞状细胞癌（5%）。梭形细胞癌和鳞状细胞癌成分均与小细胞癌巢相互交织。这是文献记载的第五例膀胱肉瘤样癌合并小细胞癌的病例。我们对该类型肿瘤临床病理特征的回顾显示：i）主要累及老年男性；ii）最常见的主要症状是血尿；iii）上皮成分可能包括尿路上皮癌、腺癌和/或鳞状细胞癌；iv）肉瘤成分由梭形细胞增生组成。该类型肿瘤的组织发生仍存在争议。然而，最近的分子分析表明两种成分均起源于单克隆。这一理论可以解释本病例中该肿瘤出现的各种类型的癌性成分。
