Occult deposition of eosinophil peroxidase in a subset of human breast carcinomas

• Published in: The American journal of pathology Vol. 148; no. 3; pp. 701 - 706
• Main Authors: Samoszuk, MK, Nguyen, V, Gluzman, I, Pham, JH
• Format: Journal Article
• Language: English
• Published: Bethesda, MD ASIP 01-03-1996; American Society for Investigative Pathology
• Subjects: Biological and medical sciences; Breast Neoplasms - enzymology; Breast Neoplasms - pathology; Carcinoma, Ductal, Breast - enzymology; Carcinoma, Ductal, Breast - pathology; Carcinoma, Lobular - enzymology; Carcinoma, Lobular - pathology; Eosinophil Peroxidase; Eosinophils - enzymology; Female; Gynecology. Andrology. Obstetrics; Histocytochemistry; Humans; Immunohistochemistry; Mammary gland diseases; Medical sciences; Peroxidase - metabolism; Peroxidases - metabolism; Tumors; Human; Immunohistochemistry; Carcinoma; Immune response; Enzyme; Pathogenesis; Granulocyte; Malignant tumor; Eosinophil; Pathology; Mammary gland diseases; Peroxidases; Degranulation; Oxidoreductases; Mammary gland
• ISSN: 0002-9440; 1525-2191

Degranulation of eosinophils has been observed in a variety of human tumors and in other diseases but has not been previously described in breast cancer. To determine whether eosinophil degranulation also occurs in breast carcinomas, we performed immunohistological studies on cryostat sections obtained from 26 breast cancer biopsies and from 2 benign breast tissues using a monoclonal antibody specific for human eosinophil peroxidase (EPO). For control purposes, the tissues were also immunostained with a mouse IgG1 negative control antibody and with monoclonal mouse anti-human myeloperoxidase. Of the 26 breast cancer specimens, 14 (53%) had extensive, unsuspected deposition of EPO that was located primarily in the connective tissue stroma around and within the tumor. Only 3 of the breast cancer cases had no immunohistochemical evidence of EPO. Thus, 23 of 26 cases of breast cancer (88%) had EPO deposits detectable within or around the tumor. By contrast, none of the benign breast tissues had similar deposits of EPO, and substantial extracellular myeloperoxidase deposition was detectable in only 3 cases of breast cancer. From these studies we conclude that there is eosinophil degranulation and extensive occult deposition of EPO in a major subset of human breast cancers.