Jassim Sarmad H, Khiyami Amer, Nguyen Jane K, Ganesan Santhi, Tomashefski Joseph, Sawady Joram
Department of Pathology, MetroHealth Medical Center, Case Western Reserve University, Cleveland, OH, USA.
J Med Case Rep. 2017 May 12;11(1):133. doi: 10.1186/s13256-017-1295-2.
Clear cell carcinoma of the bladder is a rare variant of urinary bladder adenocarcinoma. We report a case of a patient with clear cell carcinoma of the bladder and a concordant right upper lobe pulmonary adenocarcinoma with clear cell features, and we address the role of immunohistochemistry and cytogenetic analysis in distinguishing the two primary malignancies.
Our patient was a 59-year-old African American woman who presented with hematuria. Her past medical history included invasive mammary carcinoma and end-stage renal disease treated with hemodialysis. A computed tomographic urogram revealed a 3-cm polypoid bladder mass. A follow-up chest computed tomographic scan revealed a 1-cm right upper lobe nodule. The patient underwent transurethral biopsy and subsequent radical cystectomy, as well as a transthoracic core needle biopsy of the lung nodule. Histologically, the bladder tumor consisted of flat, cuboidal to columnar cells with clear or eosinophilic cytoplasm and a hobnail appearance, organized in tubulocystic and papillary patterns. The neoplastic cells were diffusely positive for α-methylacyl-coenzyme A racemase, cancer antigen 125, and cytokeratin 7; focally positive for cytokeratin 20, P53, and carcinoembryonic antigen; and negative for thyroid transcription factor 1. The lung tumor demonstrated a glandular architecture with mucin production (positive for mucin with mucicarmine and periodic acid-Schiff with diastase stain). The neoplastic cells were diffusely positive for cytokeratin 7, napsin A, and thyroid transcription factor 1, and they were negative for cytokeratin 20 and cancer antigen 125. Genetic testing of the pulmonary neoplasm demonstrated ARID2 genomic alterations.
The presence of clear cell features in both neoplasms raised the possibility of lung metastasis from the primary bladder tumor. However, the glandular architecture of the lung neoplasm along with its distinctive immunohistochemical and genetic profiles confirmed the presence of two separate primaries.
膀胱透明细胞癌是膀胱腺癌的一种罕见变体。我们报告一例膀胱透明细胞癌患者，同时伴有具有透明细胞特征的右肺上叶肺腺癌，并探讨免疫组织化学和细胞遗传学分析在区分这两种原发性恶性肿瘤中的作用。
我们的患者是一名59岁的非裔美国女性，表现为血尿。她的既往病史包括浸润性乳腺癌和接受血液透析治疗的终末期肾病。计算机断层扫描尿路造影显示膀胱有一个3厘米的息肉样肿块。后续胸部计算机断层扫描显示右肺上叶有一个1厘米的结节。患者接受了经尿道活检及随后的根治性膀胱切除术，以及对肺结节进行的经胸芯针活检。组织学上，膀胱肿瘤由扁平、立方形至柱状细胞组成，细胞质透明或嗜酸性，呈鞋钉样外观，呈管状囊性和乳头状结构。肿瘤细胞对α-甲基酰基辅酶A消旋酶、癌抗原125和细胞角蛋白7弥漫性阳性；对细胞角蛋白20、P53和癌胚抗原局灶性阳性；对甲状腺转录因子1阴性。肺肿瘤显示有腺泡结构并产生黏液（黏液卡红染色和淀粉酶消化后的过碘酸-雪夫染色显示黏液阳性）。肿瘤细胞对细胞角蛋白7、 napsin A和甲状腺转录因子1弥漫性阳性，对细胞角蛋白20和癌抗原125阴性。对肺肿瘤进行的基因检测显示有ARID2基因改变。
两种肿瘤均存在透明细胞特征，提示可能是原发性膀胱肿瘤肺转移。然而，肺肿瘤的腺泡结构及其独特的免疫组织化学和基因特征证实存在两种独立的原发性肿瘤。
