U J - Spring 2012.pdf 530 | Case Report Keywords: urinary bladder, adenocarcinoma of lung, neoplasm metastasis, im- munohistochemistry INTRODUCTION Primary adenocarcinomas of the urinary bladder, including urachal carci-epithelial malignancies. However, secondary involvement of the blad- der by metastatic spread or direct extension from adenocarcinomas arising in other organs can also occur. The morphological and histopathological similari- ties can sometimes blur the distinctions between primary and secondary lesions, especially in biopsy specimens. for determining primary sites of metastatic adenocarcinoma. Thyroid transcrip- tion factor 1 is expressed in most primary and metastatic sites of the lung adeno- carcinomas. By contrast, expressions of TTF-1 in adenocarcinomas other than lung adenocarcinomas and their metastatic sites are rare. Primary bladder ad- enocarcinomas expressing TTF-1 have not been reported. - - enocarcinoma origin of distant sources of metastases, where the primary adeno- carcinomas can arise. However, to the best of our knowledge, differentiation between the bladder and lung adenocarcinomas using this panel has not been reported so far. CASE REPORT Hiroshi Shirakawa,1 Norihide Kozakai,1 2 Hitoshi Sugiura,3 Satoshi Hara1 Urinary Bladder Metastasis Originating from Lung Adenocarcinoma A Case Definitively Diagnosed by Immunohistochemistry Corresponding Author: Hiroshi Shirakawa, MD Department of Urology, School of Medicine, Keio University, 35 Shina- nomachi, Shinjyuku-ku, Tokyo, 160-8582, Japan Tel: +81 333 531 211 Fax: +81 332 251 985 E-mail: hiroshi_srkw@ a8.keio.jp Received May 2010 Accepted June 2010 1Department of Urology, Kawasaki Municipal Hos- pital, Kanagawa, Japan 2Department of General Thoracic Surgery, Kawa- saki Municipal Hospital, Kanagawa, Japan 3Department of Pathol- ogy, Kawasaki Municipal Hospital, Kanagawa, Japan Case Report 531Vol. 9 | No. 2 | Spring 2012 |U R O LO G Y J O U R N A L Secondary Bladder Adenocarcinoma | Shirakawa et al - showed a mixed subtype adenocarcinoma staged as IA, pT1N0M0. Subsequently, his disease re- lapsed locally and metastasized to hilar lymph nodes. He was administered induction chemo- therapy consisting of carboplatin and docetaxel, followed by gemcitabine and vinorelbine, and the - ment of urology for assessment of gross hematuria. mm in diameter that was suspected to be the cause of the patient’s urinary symptoms. A vesicolitho- tripsy was subsequently performed. During the op- eration, a 3-mm diameter papillary tumor on the right lateral wall of the bladder was incidentally cold cup biopsy of the bladder tumor. The tumor was histopathologically diagnosed as an adenocarcinoma located beneath the intact urothelial epithelium without the bladder mus- cle invasion. Immunohistochemical examination demonstrated tumor cells positive for TTF-1 and of the clinical history and the identical immuno- histochemical expression pattern in the lung and bladder adenocarcinomas, the bladder tumor was diagnosed as a metastasis of the lung adenocarci- noma. After the cold cup biopsy, no recurrence of the bladder tumor was detected by ultrasonography. However, the primary lung cancer progressed, biopsy. DISCUSSION Lung cancer is the most frequently occurring form of cancer in the world, and lung adenocar- cinoma is the most common cell type represent- ing approximately 50% of all lung cancer cases. Whereas lung cancer is a common form of cancer, bladder metastasis from the lung cancer, particu- larly from lung adenocarcinoma, is uncommon. In a computed tomography-based study exam- lung cancer, no urinary tract metastases were detected. - tients with distant metastases of lung cancer, only - tected, in which the cell type was unknown. In - cancer (four, squamous cell carcinomas; one, ad- However, lung adenocarcinoma-originated tumor and the process for diagnosis was not mentioned in this study. In individual case reports, only one Spanish article has described bladder metastasis of lung adenocarcinoma. In the absence of immunohistochemistry, a patho- logical differential diagnosis of primary or sec- similar features of primary lung and secondary bladder adenocarcinomas complicate the ability Figure 1. Computed tomography scan of the chest per- formed prior to lobectomy revealed a primary lung adeno- carcinoma with a cross section of 20 × 12 mm in the upper lobe of the right lung (arrow). 532 | to differentiate between these two lesion types, especially in biopsy specimens. In the present case, clinical history and immunohistochemical the diagnosis of bladder metastasis originating from the previous lung adenocarcinoma. The in- tact urothelial epithelium overlying the bladder tumor, which suggests that a tumor is a secondary lesion, also contributed to the differential diagno- sis. In the present case, lung adenocarcinoma had already relapsed and the distinctive diagnosis of the bladder tumor of the pulmonary origin regret- tably did not affect subsequence survival. How- ever, considering the high prevalence of lung ad- enocarcinomas and the knowledge that bladder - mary bladder epithelial malignancies, urologists and thoracic surgeons will potentially encounter patients with both bladder adenocarcinomas and likely localized lung adenocarcinomas. For such patients, differential diagnoses for determining whether the bladder adenocarcinoma is primary or metastatic are essential to treat them optimally. Therefore, the immunohistochemical panel of - able method for distinguishing between primary and secondary bladder adenocarcinomas, is clini- CONFLICT OF INTEREST None declared. Figure 2. Gross appearance of the urinary bladder tumor dur- ing the cold cup biopsy. Figure 3. Histopathological findings. (a, b) Primary lung adenocarcinoma. Immunohistochemically positive for thyroid b: TTF-1, ×100). (c, d) Metastatic site in the urinary bladder. The adenocarcinoma is visible under an intact urothelial epitheli- um with Hematoxylin and Eosin staining. 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