Department of Pathology, School of Medicine, Pusan National University, Yangsan, Korea.
Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea.
Diagn Pathol. 2020 Oct 6;15(1):123. doi: 10.1186/s13000-020-01042-7.
The presence of histologically different neoplasms in the same organ is rare in pathologic practice. We report the first case of synchronous clear cell renal cell carcinoma (clear cell RCC) and papillary renal neoplasm with reverse polarity (PRNRP) with comprehensive immunohistochemical and molecular characterization using next-generation sequencing (NGS).
A 61-year-old man was incidentally found to have a left renal mass on imaging studies performed for workup of left back pain and urine color change for 1 week. A laparoscopic left radical nephrectomy was performed. Gross examination showed lobulated masses measuring 5.6 × 4.0 × 3.3 cm in the upper to mid pole and 1.1 × 1.0 × 1.0 cm in the lower pole. Microscopic findings revealed these to be two different separate masses of clear cell renal cell carcinoma and papillary renal neoplasm with reverse polarity. NGS analyses revealed KRAS gene mutation (c.35G > T/p.G12V in exon 2) in the papillary renal neoplasm with reverse polarity, with PIK3CA gene mutation restricted to the clear cell renal cell carcinoma (c.1624G > A/p.E542K in exon 10).
We report here an extraordinarily rare case of synchronous renal tumors of papillary renal neoplasm with reverse polarity and clear cell renal cell carcinoma. We identified simultaneous KRAS and PIK3CA mutations in two different renal masses in the same kidney for the first time. New pathologic assessment with comparative molecular analysis of mutational profiles may be helpful for tumor studies.
在病理实践中，同一器官内同时存在组织学上不同的肿瘤非常罕见。我们报告首例同时存在透明细胞肾细胞癌（clear cell RCC）和具有反向极性的乳头状肾肿瘤（PRNRP）的病例，通过下一代测序（NGS）进行全面的免疫组织化学和分子特征分析。
一名 61 岁男性因左腰痛和尿液颜色改变 1 周进行影像学检查时偶然发现左肾肿块。行腹腔镜左肾根治性切除术。大体检查显示上极至中极有 5.6×4.0×3.3cm 的分叶状肿块和下极有 1.1×1.0×1.0cm 的肿块。显微镜下观察发现这是两个不同的独立的透明细胞肾细胞癌和具有反向极性的乳头状肾肿瘤。NGS 分析显示具有反向极性的乳头状肾肿瘤存在 KRAS 基因突变（c.35G>T/p.G12V 位于外显子 2），而仅在透明细胞肾细胞癌中存在 PIK3CA 基因突变（c.1624G>A/p.E542K 位于外显子 10）。
我们在此报告一例非常罕见的同时存在具有反向极性的乳头状肾肿瘤和透明细胞肾细胞癌的肾肿瘤病例。我们首次在同一肾脏的两个不同肾肿块中发现同时存在 KRAS 和 PIK3CA 突变。新的病理评估与突变谱的比较分子分析可能有助于肿瘤研究。
