Premium
Nucleolar organizer regions in fibrohistiocytic tumors of the skin
Author(s) -
Merot Yves,
Durgniat AnneChristine,
Frenk Edgar
Publication year - 1990
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/j.1600-0560.1990.tb00068.x
Subject(s) - dermatofibrosarcoma protuberans , nucleolus , pathology , atypia , nuclear atypia , silver stain , biology , nucleolus organizer region , differential diagnosis , immunohistochemistry , medicine , microbiology and biotechnology , nucleus
Nucleolar organizer regions (NORs) are loops of DNA which are present within the nucleoli of cells that possess ribosomal RNA (rRNA) genes. NORs are associated with proteins which can be visualized by a simple silver staining technique. As the number of NORs appears to reflect cell and nuclear activity its determination in benign, intermediate and malignant conditions could be of help in their differential diagnosis. In this study, we investigated 35 fibrohistiocytic tumors of the skin of benign, intermediate and malignant potential from 32 patients: 15 fibrous histiocytomas (FH), 5 FH with atypia (AFH), 7 atypical fibroxanthomas (AFX), 5 dermatofibrosarcoma protuberans (DFSP) and 3 malignant FH (MFH). A one‐step silver technique was used on formalin or Bouin fixed specimens. Ag‐NOR counts from benign conditions (FH, AFH) significantly differed from that of their intermediate‐risk (AFX, DFSP) and malignant (MFH) counterparts. Furthermore, in 2 cases (one AFX; one MFH) which twice recurred, Ag‐NOR counts steadily increased with time. However, a distinction could not be achieved between AFX and MFH. Although Ag‐NOR is a simple and valuable technique, it does not allow a definite distinction between malignant and intermediate processes, at least as far as fibrohistiocytic tumors of the skin are concerned.