J Biomed Transl Res.  2020 Jun;21(2):95-99. 10.12729/jbtr.2020.21.2.095.

Exploration of the developmental process of vasculogenic mimicry in canine inflammatory mammary carcinoma

• Choi JS
• Oh YI
• Lee BW
• Kim HW
• Yoon BI

• KMID: 2503835
• DOI: http://doi.org/10.12729/jbtr.2020.21.2.095

Abstract

Canine inflammatory mammary carcinoma (CIMC) similar to human inflammatory breast cancer is a very aggressive, metastatic type of cancer. Previous studies have introduced a new type of tumor angiogenesis called vasculogenic mimicry that may play an important role in the progression of inflammatory mammary cancer. The purpose of this study is to investigate the development process of vessels by neoplastic cells in CIMC. Patient dog, 14-year old Shit-Tzu female, had a hard and somewhat movable dark-reddish mammary tumor, sized 6.2 cm in diameter. Bloody dark turbid exudate was released from the tumor. In addition to histological examination, immunohistochemistry for pancytokeratin, VCAM-1, MECA- 32, TWIST-1, and Ki-67 was respectively performed using the ABC method. Histologically, the inflammatory mammary carcinoma was characterized by tubular solid tumor emboli within the lymphatic vessels surrounded by desmoplastic fibrous connective tissue. Some of the neoplastic cells were transforming into elongate or spindle shapes and forming small vessel-like structures in the solid tumor mass. The neoplastic cells were immunoreactive for VCAM-1 and MECA-32, but showed low immunoreactivity for Ki-67. Immunoreactive neoplastic cells for VCAM-1 and MECA-32 suggested the possibility that the neoplastic cells transform into endothelial cells of vessels by epithelial-mesenchymal transition, further supported by serial morphological changes identified by histological investigation and immunohistochemistry for TWIST-1. The high capacity of the neoplastic cells forming the vasculatures in CIMC explains the high ratio of metastasis to other regions, even though Ki-67 index was not so high.

Keyword

canine inflammatory mammary carcinoma; immunohistochemistry; TWIST-1; vasculogenic mimicry; VCAM-1