Vol 48, No 3 (2010)
Original paper
Submitted: 2011-12-19
Published online: 2010-11-13
Type II muscle fibers atrophy associated with silent corticotroph adenoma in a dog.
F Trapani, M L Del Basso De Caro, L Insabato, S Papparella, O Paciello
DOI: 10.2478/v10042-010-0038-7
·
Folia Histochem Cytobiol 2010;48(3):403-406.
Vol 48, No 3 (2010)
ORIGINAL PAPERS
Submitted: 2011-12-19
Published online: 2010-11-13
Abstract
The Silent Corticotroph Adenoma (SCA) is a pituitary adenoma variant characterized by the immunoreactivity for adrenocorticotropic hormone (ACTH) and related peptides, without the clinical signs of Cushing's disease. SCA has been postulated to either secrete structurally abnormal ACTH that is inactive but detectable by immunohistochemistry or radioimmunoassay, or to secrete ACTH intermittently or at low levels continuously. Excess of ACTH has been associated to type II muscle atrophy. We describe a case of type II muscle fibers atrophy associated with silent corticotroph adenoma in a dog. The dog showed moderate to severe proximal muscle wasting and weakness with normal levels of muscle-associated enzymes. In the limb muscle biopsies, type II fibers were uniformly smaller than type I fibers. In temporalis muscles, there were few atrophic fibers, and several irregular areas of loss of enzymatic activity observed in NADH, SDH and COX stains. The tumour showed a trabecular growth pattern and immunohistochemical analysis demonstrated the presence of cytoplasmic immunoreactivity for ACTH. The muscle atrophy was considered to be related to an excess of inactive ACTH. Studying spontaneous occurring rare diseases in animals could help to understand the mechanism of similar diseases in human has well.
Abstract
The Silent Corticotroph Adenoma (SCA) is a pituitary adenoma variant characterized by the immunoreactivity for adrenocorticotropic hormone (ACTH) and related peptides, without the clinical signs of Cushing's disease. SCA has been postulated to either secrete structurally abnormal ACTH that is inactive but detectable by immunohistochemistry or radioimmunoassay, or to secrete ACTH intermittently or at low levels continuously. Excess of ACTH has been associated to type II muscle atrophy. We describe a case of type II muscle fibers atrophy associated with silent corticotroph adenoma in a dog. The dog showed moderate to severe proximal muscle wasting and weakness with normal levels of muscle-associated enzymes. In the limb muscle biopsies, type II fibers were uniformly smaller than type I fibers. In temporalis muscles, there were few atrophic fibers, and several irregular areas of loss of enzymatic activity observed in NADH, SDH and COX stains. The tumour showed a trabecular growth pattern and immunohistochemical analysis demonstrated the presence of cytoplasmic immunoreactivity for ACTH. The muscle atrophy was considered to be related to an excess of inactive ACTH. Studying spontaneous occurring rare diseases in animals could help to understand the mechanism of similar diseases in human has well.
Title
Type II muscle fibers atrophy associated with silent corticotroph adenoma in a dog.
Journal
Folia Histochemica et Cytobiologica
Issue
Vol 48, No 3 (2010)
Article type
Original paper
Pages
403-406
Published online
2010-11-13
Page views
2066
Article views/downloads
2322
DOI
10.2478/v10042-010-0038-7
Bibliographic record
Folia Histochem Cytobiol 2010;48(3):403-406.
Authors
F Trapani
M L Del Basso De Caro
L Insabato
S Papparella
O Paciello
About this article