title: [Clinical and pathologic features of tubulocystic carcinoma of kidney].
abstract: OBJECTIVE
  To investigate clinicopathological features and differential diagnosis of tubulocystic carcinoma of the kidney.
  
  
  METHODS
  The clinical features, histological and immunohistochemical findings were analyzed in 3 cases of tubulocystic carcinoma of the kidney, along with review of the related literatures.
  
  
  RESULTS
  Three patients were males with a mean age of 59 years old (range from 44 to 71 years). All presented with no symptom and their tumors were found during routine examination. The tumor size ranged from 1.5 to 5.0 cm in greatest dimension. The tumors were grossly well-circumscribed without capsules and exhibited a spongy cut surface. Microscopically, all three tumors were composed of tubules and cysts of varying sizes separated by thin fibrous septa. The epithelial lining cells were flat, cuboidal and columnar, with often a hobnail-like appearance characterized by abundant eosinophilic cytoplasm with prominent nucleoli. Two cases showed focal clear cytoplasm. One of the three cases coexisted with a papillary renal cell carcinoma. Immunohistochemically, all 3 cases showed positivity for pan-CK, vimentin, CK19, CD10, P504S, and focal positivity for 34βE12. Two cases showed focal positivity for CK7.
  
  
  CONCLUSIONS
  Tubulocystic carcinoma of the kidney is a rare kidney neoplasm and occurs predominantly in males. The tumor is characterized by gross spongy appearance and microscopic cysts and tubules often lined by hobnail-like cells and separated by thin fibrotic stroma. The differential diagnosis mainly includes other lesions of the kidney that have a multicystic growth pattern.
authors.affiliation: Department of Pathology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, China. happies0100@yahoo.com.cn
authors.forename: Shu-Hong
authors.initials: SH
authors.lastname: Zhang
authors.forename: Shu-Fang
authors.initials: SF
authors.lastname: Shi
authors.forename: Shou-Fang
authors.initials: SF
authors.lastname: Huang
authors.forename: Yan-Ning
authors.initials: YN
authors.lastname: Zhang
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Zheng
authors.forename: Guang-Yong
authors.initials: GY
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D002292:Carcinoma, Renal Cell / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D053539:Keratin-19 / Q000378:metabolism; D007680:Kidney Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D011379:Prognosis; D019998:Racemases and Epimerases / Q000378:metabolism
chemical_list: D053539:Keratin-19; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase