Department of Pathology, Robert J. Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH.
Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN.
Am J Surg Pathol. 2021 Apr 1;45(4):516-522. doi: 10.1097/PAS.0000000000001680.
We identified an unusual pattern of renal tubular proliferation associated with chronic renal disease, found in 23 patients, diffusely (n=12), or focally (n=11). Incidence was 5% of end-stage renal disease kidneys from one institution (8/177) and 7/23 patients with acquired cystic kidney disease-associated renal cell carcinoma from another. Most (19 patients) had 1 or more neoplasms including papillary (n=9), acquired cystic kidney disease (n=8), clear cell (n=4), or clear cell papillary (n=3) renal cell carcinoma. All (20 men, 3 women) had end-stage renal disease. The predominant pattern (n=18) was the indentation of chronic inflammation into renal tubules forming small polypoid structures; however, 5 had predominantly hyperplastic epithelium with less conspicuous inflammation. In 14 patients both patterns were appreciable, whereas the remainder had only the inflammatory pattern. Immunohistochemistry was positive for cytokeratin 7, high-molecular-weight cytokeratin, PAX8, and GATA3. Staining for alpha-methylacyl-CoA racemase was negative or weak, dramatically less intense than papillary neoplasms or proximal tubules. CD3 and CD20 showed a mixture of B and T lymphocytes in the inflammatory areas. Fluorescence in situ hybridization showed no trisomy 7 or 17 or loss of Y (n=9). We describe a previously uncharacterized form of renal tubular proliferation that differs from papillary adenoma (with weak or negative alpha-methylacyl-CoA racemase, lack of trisomy 7 or 17, and sometimes diffuse distribution). On the basis of consistent staining for high-molecular-weight cytokeratin and GATA3, we propose the name distal tubular hyperplasia for this process. Future studies will be helpful to assess preneoplastic potential and etiology.
我们发现了 23 例与慢性肾脏病相关的不寻常肾小管增生模式，弥漫性（n=12）或局灶性（n=11）分布。在一家机构的终末期肾脏病肾脏中，发病率为 5%（8/177），另一家机构的获得性囊性肾病相关肾细胞癌患者中有 7/23 例。大多数患者（19 例）有 1 个或多个肿瘤，包括乳头状（n=9）、获得性囊性肾病（n=8）、透明细胞（n=4）或透明细胞乳头状（n=3）肾细胞癌。所有患者（20 名男性，3 名女性）均患有终末期肾脏病。主要模式（n=18）是慢性炎症浸润肾小管形成小息肉样结构；然而，5 例以增生性上皮为主，炎症不明显。在 14 例患者中，两种模式均明显，而其余患者仅有炎症模式。免疫组织化学染色显示细胞角蛋白 7、高分子量细胞角蛋白、PAX8 和 GATA3 阳性。α-甲基酰基辅酶 A 消旋酶染色阴性或弱阳性，明显弱于乳头状肿瘤或近端肾小管。CD3 和 CD20 在炎症区域显示 B 和 T 淋巴细胞混合存在。荧光原位杂交显示无三体 7 或 17 或 Y 丢失（n=9）。我们描述了一种以前未描述的肾小管增生形式，与乳头状腺瘤不同（α-甲基酰基辅酶 A 消旋酶弱或阴性，无三体 7 或 17，有时弥漫性分布）。基于高分子量细胞角蛋白和 GATA3 的一致染色，我们提出该过程的名称为远端肾小管增生。未来的研究将有助于评估其潜在的肿瘤前状态和病因。
