A Case Report of Invasive Pituitary Tumors Containing Alpha-Melanocyte-Stimulating Hormone Arising from the Pars Distalis in F344 Rats

Abstract

Readers are invited to submit their own diagnostic challenges or unusual findings or to voice opinions and comments about the current lesion diagnosis or explanation. Cases for the "Tox Path Forum" should be sent to the Editorial Office with the following information: 1) species, sex, and age; 2) the nature/class of the test article (if any); 3) brief description and diagnosis; and 4) photographs or data. The information should not exceed two pages (including photographs). Submit both a hard copy and a diskette (Macintosh or PC) indicating version, to expedite rapid review and publication. Submissions will be reviewed for clarity and relevance to the journal readership. Comments (3,6,8,9,11 For immunohistochemical detection of a-MSH, prolactin (PRL), and proliferating cell nuclear antigen (PCNA), selected tissue sections were processed by a labeled streptavidin-biotin (LSAB) method. In brief, the paraffin section was deparaffinized, treated sequentially with rabbit anti-a-MSH antibody (1:500, Biogenesis, Inc, NH), rabbit anti-rat prolactin antibody (1:1,000, Chemicon International Co, Ltd, CA), or mouse anti-PCNA antibody (1:100, DAKO Japan Co., Ltd., Tokyo, Japan) as the primary antibody, followed by staining with an LSAB kit (DAKO Japan Co, Ltd