Abstract：
OBJECTIVE: Renal cell carcinoma (RCC) with clear cells and psammoma-like calcifications would often raise suspicion for MITF family translocation RCC. However, we have rarely encountered tumours consistent with clear cell RCC that contain focal psammomatous calcifications.
RESULTS: We identified clear cell RCCs with psammomatous calcifications from multiple institutions and performed immunohistochemistry and fluorescence and RNA in-situ hybridisation (FISH and RNA ISH). Twenty-one tumours were identified: 12 men, nine women, aged 45-83 years. Tumour size was 2.3-14.0 cm (median = 6.75 cm). Nucleolar grade was 3 (n = 14), 2 (n = 4) or 4 (n = 3). In addition to clear cell pattern, morphology included eosinophilic (n = 12), syncytial giant cell (n = 4), rhabdoid (n = 2), branched glandular (n = 1), early spindle cell (n = 1) and poorly differentiated components (n = 1). Labelling for CA9 was usually 80-100% of the tumour cells (n = 17 of 21), but was sometimes decreased in areas of eosinophilic cells (n = 4). All (19 of 19) were positive for CD10. Most (19 of 20) were positive for AMACR (variable staining = 20-100%). Staining was negative for keratin 7, although four showed rare positive cells (four of 20). Results were negative for cathepsin K (none of 19), melan A (none of 17), HMB45 (none of 17), TFE3 (none of 5), TRIM63 RNA ISH (none of 13), and TFE3 (none of 19) and TFEB rearrangements (none of 12). Seven of 19 (37%) showed chromosome 3p deletion. One (one of 19) showed trisomy 7 and 17 without papillary features.
CONCLUSIONS: Psammomatous calcifications in RCC with a clear cell pattern suggests a diagnosis of MITF family translocation RCC; however, psammomatous calcifications can rarely be found in true clear cell RCC.
RESULTS: We identified clear cell RCCs with psammomatous calcifications from multiple institutions and performed immunohistochemistry and fluorescence and RNA in-situ hybridisation (FISH and RNA ISH). Twenty-one tumours were identified: 12 men, nine women, aged 45-83 years. Tumour size was 2.3-14.0 cm (median = 6.75 cm). Nucleolar grade was 3 (n = 14), 2 (n = 4) or 4 (n = 3). In addition to clear cell pattern, morphology included eosinophilic (n = 12), syncytial giant cell (n = 4), rhabdoid (n = 2), branched glandular (n = 1), early spindle cell (n = 1) and poorly differentiated components (n = 1). Labelling for CA9 was usually 80-100% of the tumour cells (n = 17 of 21), but was sometimes decreased in areas of eosinophilic cells (n = 4). All (19 of 19) were positive for CD10. Most (19 of 20) were positive for AMACR (variable staining = 20-100%). Staining was negative for keratin 7, although four showed rare positive cells (four of 20). Results were negative for cathepsin K (none of 19), melan A (none of 17), HMB45 (none of 17), TFE3 (none of 5), TRIM63 RNA ISH (none of 13), and TFE3 (none of 19) and TFEB rearrangements (none of 12). Seven of 19 (37%) showed chromosome 3p deletion. One (one of 19) showed trisomy 7 and 17 without papillary features.
CONCLUSIONS: Psammomatous calcifications in RCC with a clear cell pattern suggests a diagnosis of MITF family translocation RCC; however, psammomatous calcifications can rarely be found in true clear cell RCC.
摘要：
目的：肾细胞癌（RCC）伴有透明细胞和沙膜样钙化，常引起MITF家族易位RCC的怀疑。然而,我们很少遇到与透明细胞RCC一致的肿瘤，这些肿瘤含有局灶性砂膜钙化。
结果：我们从多个机构鉴定了透明细胞RCC，并进行了免疫组织化学，荧光和RNA原位杂交（FISH和RNAISH）。确定了21个肿瘤：12名男性，9女人，年龄45至83岁。肿瘤大小2.3～14.0cm，中位数6.75cm。核仁等级为3级（n=14），2（n=4），或4（n=3）。除了清晰的细胞模式，形态包括嗜酸性粒细胞（n=12），合胞体巨细胞(n=4),横纹肌（n=2），分支腺体（n=1），早期梭形细胞（n=1），和低分化成分(n=1)。CA9标记通常占肿瘤细胞的80-100％（n=17/21），但有时在嗜酸性细胞区域减少（n=4）。全部(19/19)为CD10阳性。大多数(19/20)为AMACR阳性(可变染色，20-100%）。角蛋白7染色为阴性,尽管4个显示罕见的阳性细胞(4/20)。结果为组织蛋白酶K阴性（0/19），melanA(0/17),HMB45(0/17),TFE3(0/5),TRIM63RNA-ISH（0/13），和TFE3（0/19）和TFEB重排（0/12）。19个中的7个(37%)显示染色体3p缺失。一个（1/19）显示7和17三体，没有乳头状特征。
结论：肾细胞癌组织有透明细胞模式的膜膜钙化提示诊断为MITF家族易位肾细胞癌；然而，在真正的透明细胞RCC中很少发现晶状体钙化。
结果：我们从多个机构鉴定了透明细胞RCC，并进行了免疫组织化学，荧光和RNA原位杂交（FISH和RNAISH）。确定了21个肿瘤：12名男性，9女人，年龄45至83岁。肿瘤大小2.3～14.0cm，中位数6.75cm。核仁等级为3级（n=14），2（n=4），或4（n=3）。除了清晰的细胞模式，形态包括嗜酸性粒细胞（n=12），合胞体巨细胞(n=4),横纹肌（n=2），分支腺体（n=1），早期梭形细胞（n=1），和低分化成分(n=1)。CA9标记通常占肿瘤细胞的80-100％（n=17/21），但有时在嗜酸性细胞区域减少（n=4）。全部(19/19)为CD10阳性。大多数(19/20)为AMACR阳性(可变染色，20-100%）。角蛋白7染色为阴性,尽管4个显示罕见的阳性细胞(4/20)。结果为组织蛋白酶K阴性（0/19），melanA(0/17),HMB45(0/17),TFE3(0/5),TRIM63RNA-ISH（0/13），和TFE3（0/19）和TFEB重排（0/12）。19个中的7个(37%)显示染色体3p缺失。一个（1/19）显示7和17三体，没有乳头状特征。
结论：肾细胞癌组织有透明细胞模式的膜膜钙化提示诊断为MITF家族易位肾细胞癌；然而，在真正的透明细胞RCC中很少发现晶状体钙化。
