title: Oncocytic renal cell carcinoma having papillotubular growth: rare morphological variant of papillary renal cell carcinoma.
abstract: Herein is described a unique renal cell tumor with previously unreported morphological and immunohistochemical features. The patient was a 78-year-old Japanese man. A huge left renal tumor was found on ultrasound during evaluation of left abdominal distention. The tumor was macroscopically characterized by a non-infiltrative border, pale yellow to grayish color, foci of hemorrhage and partial edematous change. Histologically the tumor had an extensive small tubular growth pattern often with papillary fronds mainly composed of oncocytic cells with deeply eosinophilic granular cytoplasm. Clear vacuolated cells were scattered among the oncocytic cells. The present case had an unusual immunohistochemical profile for all known types of renal cell tumors, but both the oncocytic cells and the clear vacuolated cells were strongly immunoreactive for alpha-methylacyl-coenzyme A racemase. It is concluded that the tumor may be a candidate for a rare variant of papillary renal cell carcinoma. Further cases having similar features are awaited for a definitive classification of this tumor as a previously undescribed tumor type.
authors.affiliation: Department of Pathology, Otsu Municipal Hospital, Otsu, Japan. otsu-ho9@mx.cable-net.ne.jp
authors.forename: Naoko
authors.initials: N
authors.lastname: Masuzawa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kishimoto
authors.forename: Ayako
authors.initials: A
authors.lastname: Nishimura
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Shichiri
authors.forename: Akio
authors.initials: A
authors.lastname: Yanagisawa
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis; D002291:Carcinoma, Papillary / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D002292:Carcinoma, Renal Cell / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007680:Kidney Neoplasms / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D008297:Male; D019998:Racemases and Epimerases / Q000032:analysis; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase