Department of Pathology, The Affiliated Hospital of Qingdao University, Qingdao, China.
Department of Pathology, The 971 Hospital of People's Liberation Army Navy, Qingdao, China.
Pathol Res Pract. 2022 Jul;235:153960. doi: 10.1016/j.prp.2022.153960. Epub 2022 May 27.
This study aimed to investigate the clinicopathological and molecular characteristics of ELOC(TCEB1)-mutant renal cell carcinoma.
Sanger sequencing was used to assess 32 cases originally diagnosed as clear cell renal cell carcinoma with CK7 positive and/or fibromyomatous stroma. Of these, 4 patients with ELOC(TCEB1) gene mutation were screened, and their clinicopathological data were collected for histomorphological observation, immunohistochemical staining, and follow-up, and relevant pieces of literature were reviewed.
The 4 patients with ELOC(TCEB1) mutations were all males and aged between 57 and 64 years (median age: 59 years old). The tumor was located in the renal cortex, with a diameter of 2-3.5 cm. The cross-section was grayish-yellow and grayish brown, solid and nodular, and clearly demarcated from the surrounding tissues. Of the 4 patients, 3 harbored a thick fibrous pseudocapsule rich in smooth muscle and were separated from the surrounding normal renal tissue, and 2 of them showed focal invasion into the pseudocapsule, whereas 1 patient had no capsule but had focal invasion into the surrounding renal parenchyma. The tumor tissues mainly exhibited elongated or branched aciniform or tubular structures, commonly accompanied by interspersed small cystic and focal clustered short papillary structures. The cytoplasm of the tumor cells was rich and lightly stained, and the nuclear grading ranged from 1 to 2. All patients showed loose edema in the stroma, and 2 patients showed a small number of interspersed smooth muscle bundles. All 4 patients showed EMA, CA9, AMACR, and TCEB1 expression, and TCEB1 was mainly located in the nucleus. Vimentin, CK7, and CD10 expressions were observed in most cases; CD117, TFE3, HMB45, and melanA were not expressed in all tumors; the expression rate of Ki67 was 3%- 8%. All 4 patients had a point mutation in ELOC(TCEB1) Y79C. The patients were followed up for 24-93 months (mean 49 months), and all of them survived to date without recurrence or metastasis.
ELOC(TCEB1)-mutant renal cell carcinoma is a rare type of renal cell carcinoma, which tends to occur in middle-aged and elderly men. The main characteristics of this tumor are the branching alveolar or tubular structure with clustered short papillae, presence of fibromyomatous stroma, and the expression of CK7, CA9, CD10, and AMACR. Positive TCEB1 nuclear staining may be an important marker and the Sanger sequencing method is helpful for the diagnosis of this type of RCC. Most patients harbor tumors exhibiting low nuclear grade and inert clinical behavior, and a few tumors exhibit high nuclear grade and aggressive characteristics.
本研究旨在探讨 ELOC（TCEB1）突变型肾细胞癌的临床病理和分子特征。
采用 Sanger 测序方法对 32 例最初诊断为 CK7 阳性和/或纤维肌性基质的透明细胞肾细胞癌进行评估。其中筛选出 4 例 ELOC（TCEB1）基因突变患者，收集其临床病理资料进行组织形态学观察、免疫组织化学染色和随访，并复习相关文献。
4 例 ELOC（TCEB1）突变患者均为男性，年龄 57-64 岁（中位年龄：59 岁）。肿瘤位于肾皮质，直径 2-3.5cm。切面呈灰白色至棕褐色，实性，结节状，与周围组织界限清楚。4 例患者中，3 例有富含平滑肌的厚纤维假包膜，与周围正常肾组织分离，其中 2 例包膜局部侵犯，1 例无包膜，但局部侵犯周围肾实质。肿瘤组织主要表现为伸长或分支的腺样或管状结构，常伴有散在的小囊性和局灶簇状短乳头结构。肿瘤细胞细胞质丰富，染色浅，核分级 1-2 级。所有患者的基质均有疏松水肿，2 例患者有少量散在的平滑肌束。4 例患者均表达 EMA、CA9、AMACR 和 TCEB1，TCEB1 主要位于细胞核。大多数病例表达波形蛋白、CK7 和 CD10；所有肿瘤均不表达 CD117、TFE3、HMB45 和 melanA；Ki67 的表达率为 3%-8%。4 例患者均存在 ELOC（TCEB1）Y79C 点突变。患者随访 24-93 个月（平均 49 个月），均存活，无复发或转移。
ELOC（TCEB1）突变型肾细胞癌是一种罕见的肾细胞癌，多见于中老年男性。该肿瘤的主要特征为分支肺泡或管状结构伴簇状短乳头、纤维肌性基质存在、CK7、CA9、CD10 和 AMACR 表达阳性。TCEB1 核染色阳性可能是一个重要的标志物，Sanger 测序有助于此类 RCC 的诊断。大多数患者的肿瘤具有低核级和惰性的临床行为，少数肿瘤具有高核级和侵袭性特征。
