Department of Diagnostic Radiology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 7340037, Japan.
Department of Urology, Institute of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 7340037, Japan.
Abdom Radiol (NY). 2017 Jul;42(7):1850-1856. doi: 10.1007/s00261-017-1189-1.
Papillary renal cell carcinoma (P-RCC) typically exhibits a homogeneous, solid hypovascular mass; P-RCC with a cystic appearance is atypical. Tubulocystic RCC (TC-RCC), a newly proposed entity for renal tumors in the 2016 WHO classification, and cystic papillary RCC, may yield similar imaging findings. Therefore, we investigated the incidence of papillary RCC with cystic changes and compared its CT and pathologic features to differentiate between two entities.
We retrospectively evaluated 26 consecutive patients diagnosed with P-RCC. Two radiologists consensually identified dominant masses indicative of cystic changes on CT scans and recorded their Bosniak classification. In addition, two pathologists inspected the whole area of tumors macroscopically, labeled them as solid- or cystic change-dominant tumors, determined the pathogenesis of the cystic components (necrosis or hemorrhage), and recorded their inherent cystic characteristics (with/without TC-RCC components). We defined masses with cystic changes involving more than 50% of the entire tumor as cystic change-dominant tumors.
Of the 26 tumors, 7 (27%) were diagnosed cystic change-dominant based on imaging and pathologic findings, of these, 2 were classified as Bosniak type III and 5 as Bosniak type IV. The pathologists confirmed that two type IV tumors demonstrated extensive necrosis and one type IV tumor revealed extensive hemorrhage. Four P-RCCs (type III and IV, 2 each) were of a mixed type harboring both solid and cystic components. Only one tumor exhibited a multilocular cystic appearance. All 7 cystic change-dominant P-RCCs were pathologically diagnosed as a pure P-RCC without TC-RCC components.
While P-RCCs may contain cystic features, the multilocular type of cystic P-RCC is rare.
乳头状肾细胞癌 (P-RCC) 通常表现为均匀、实性、少血供的肿块；囊性表现的 P-RCC 则不典型。管状囊性肾细胞癌 (TC-RCC) 是 2016 年 WHO 分类中提出的一种新的肾肿瘤实体，囊性乳头状肾细胞癌可能具有相似的影像学表现。因此，我们研究了具有囊性改变的乳头状肾细胞癌的发生率，并比较了其 CT 和病理特征以区分这两种实体。
我们回顾性评估了 26 例连续诊断为 P-RCC 的患者。两名放射科医生一致确定 CT 扫描上提示囊性改变的优势肿块，并记录其 Bosniak 分类。此外，两名病理学家分别对肿瘤的整个区域进行宏观检查，标记为实性或囊性改变为主的肿瘤，确定囊性成分的发病机制（坏死或出血），并记录其固有的囊性特征（是否存在 TC-RCC 成分）。我们将囊性改变占整个肿瘤 50%以上的肿块定义为囊性改变为主的肿瘤。
在 26 个肿瘤中，有 7 个（27%）根据影像学和病理学发现被诊断为囊性改变为主，其中 2 个被分类为 Bosniak Ⅲ型，5 个为 Bosniak Ⅳ型。病理学家证实，两个Ⅳ型肿瘤表现为广泛坏死，一个Ⅳ型肿瘤表现为广泛出血。4 个 P-RCC（Ⅲ型和Ⅳ型，各 2 个）为混合性，既有实性成分也有囊性成分。只有一个肿瘤表现为多房囊性外观。所有 7 个囊性改变为主的 P-RCC 均经病理诊断为无 TC-RCC 成分的纯 P-RCC。
虽然 P-RCC 可能包含囊性特征，但多房囊性 P-RCC 很少见。
