Oncocytic modifications in rectal adenocarcinomas after radio and chemotherapy.
The purpose of the study is to highlight oncocytic modifications in rectal adenocarcinomas and evaluate a possible correlation with preoperative radiochemotherapy (RCT). Twenty-eight cases of advanced rectal carcinoma, treated preoperatively by 5-fluorouracil (200-225 mg/m(2)) and 44-46 Gy in 22-23 fractions, were studied. All patients underwent biopsy before RCT. Surgery was performed within 6 weeks after RCT. In all cases oncocytic modifications were searched for on hematoxylin and eosin (H&E) and at immunohistochemistry using an antimitochondrial antibody. In addition, in two cases, both pre- and post-RCT tissues were examined at electron microscopy. All tumors were adenocarcinomas. In pre-RCT biopsies, oncocytic changes were difficult to find on H&E, while the antimitochondrial antibody strongly stained numerous neoplastic cells (mean 48.4%). In post-RCT surgical specimens, oncocytic changes were detected in 24 out of 28 cases on H&E and the antimitochondrial antibody stained most of the residual neoplastic cells (mean 76.7%). Ultrastructural examination revealed large and bizarre mitochondria inside tumor cells both in pre- and post-RCT tissues. In conclusion, the present data suggest that rectal adenocarcinomas are "mitochondrion-rich" tumors. After preoperative RCT, residual neoplastic cells acquire a definite oncocytic phenotype.
Ambrosini-Spaltro
Andrea
A
Section of Anatomic Pathology M. Malpighi, University of Bologna, Bellaria Hospital, Bologna, Italy.
Salvi
Fabrizio
F
Betts
Christine M
CM
Frezza
Giovanni P
GP
Piemontese
Antonio
A
Del Prete
Pietro
P
Baldoni
Cristina
C
Foschini
Maria P
MP
Viale
Giuseppe
G
D000230:Adenocarcinoma / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy; D000368:Aged; D000964:Antimetabolites, Antineoplastic / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis; D002471:Cell Transformation, Neoplastic; D003593:Cytoplasm / Q000648:ultrastructure; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D008297:Male; D018365:Neoplasm, Residual / Q000473:pathology; D024862:Oxyphil Cells / Q000473:pathology*; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000188:drug therapy / Q000473:pathology* / Q000532:radiotherapy
D000964:Antimetabolites, Antineoplastic; D014408:Biomarkers, Tumor; D005472:Fluorouracil