Tanigawa Mio, Huruuchi Toru, Tamura Koetsu, Nakajima Fumio, Domoto Hideharu, Mukai Kiyoshi, Nagashima Yoji
Department of Urology, Keiyu Hospital.
Department of Pathology, Keiyu Hospital.
Nihon Hinyokika Gakkai Zasshi. 2020;111(4):134-139. doi: 10.5980/jpnjurol.111.134.
Renal cell carcinoma (RCC), the most common solid lesion of the kidney, accounts for approximately 2%-3% of all malignancies among adults. Clear cell carcinoma and papillary cell carcinoma are the most common types of renal tumors. Some case reports have described synchronous benign and malignant tumors in the same kidney. In particular, angiomyolipoma and RCC in patients with tuberous sclerosis (TSC) and non-TSC have been reported many times in the literature. However, unilateral concordance of malignant renal tumors is very rare; thus, only few cases have been reported in the literature.Here we report the case of a 58-year-old male who had ipsilateral synchronous mucinous tubular and spindle cell carcinoma (MTSCC) and clear cell papillary renal cell carcinoma (CCPRCC). Both cancers are rare and relatively recently defined subtypes of RCC. Additionally, both were successfully treated using partial nephrectomy. MTSCC has been a distinct entity in the World Health Organization classification of kidney tumors since 2004. The classic type of MTSCC is characterized by small elongated tubules lined with clear cuboidal or spindle cells with mucinous stroma. Neoplastic cells always exhibit low-grade histological features. However, unclassified variants of MTSCC, such as mucin-poor, papillary, high-grade, and sarcomatoid variants, have also been reported. MTSCC is considered to have a relatively good prognosis, but some patients with poor prognoses have recently been reported. CCPRCC is a recently recognized entity and represents the fourth most common variant of RCC. It has unique morphological and immunohistochemical features and shows indolent clinical behavior. Microscopically, CCPRCC may mimic other RCCs with clear cell features, such as clear cell RCC, translocation RCC, and papillary RCC, with clear cell changes. In 2006, CCPRCC was described as a subtype of renal tumors in patients with end-stage renal disease. However, currently, CCPRCC has also been shown to occur in kidneys with normal function.To the best of our knowledge, this is the first report of ipsilateral synchronous MTSCC and CCPRCC, which we present with a review of the pertinent literature.
肾细胞癌（RCC）是肾脏最常见的实体性病变，约占成人所有恶性肿瘤的2%-3%。透明细胞癌和乳头状细胞癌是最常见的肾肿瘤类型。一些病例报告描述了同一侧肾脏内同时存在良性和恶性肿瘤。特别是，结节性硬化症（TSC）患者和非TSC患者的肾血管平滑肌脂肪瘤和RCC在文献中已有多次报道。然而，恶性肾肿瘤单侧一致性非常罕见；因此，文献中仅报道了少数病例。在此，我们报告一例58岁男性患者，其同侧同时存在黏液性小管和梭形细胞癌（MTSCC）及透明细胞乳头状肾细胞癌（CCPRCC）。这两种癌症均为罕见且相对较新定义的RCC亚型。此外，二者均通过肾部分切除术成功治疗。自2004年起，MTSCC在世界卫生组织肾脏肿瘤分类中已成为一个独立的实体。经典型MTSCC的特征是由内衬透明立方状或梭形细胞的小细长小管及黏液性间质组成。肿瘤细胞总是表现出低级别组织学特征。然而，也有未分类的MTSCC变异型报道，如黏液缺乏型、乳头状型、高级别型和肉瘤样变异型。MTSCC被认为预后相对较好，但最近也有一些预后不良的患者报道。CCPRCC是一种最近才被认识的实体，是RCC的第四种最常见变异型。它具有独特的形态学和免疫组化特征，临床行为惰性。在显微镜下，CCPRCC可能会与其他具有透明细胞特征的RCC相似，如透明细胞RCC、易位性RCC和乳头状RCC，并伴有透明细胞改变。2006年，CCPRCC被描述为终末期肾病患者肾肿瘤的一种亚型。然而，目前也已证明CCPRCC可发生于功能正常的肾脏。据我们所知，这是同侧同时发生MTSCC和CCPRCC的首例报告，我们将其与相关文献回顾一并呈现。
