Mondor's disease of breast is a variant of:

Mondor's disease is a variant of thrombophlebitis that involves the superficial veins of the anterior chest wall and breast. In 1939, Mondor described the condition as "string phlebitis," a thrombosed vein presenting as a tender, cord-like structure. Frequently involved veins include the lateral thoracic vein, the thoracoepigastric vein, and, less commonly, the superficial epigastric vein. Typically, a woman presents with acute pain in the lateral aspect of the breast or the anterior chest wall. A tender, firm cord is found to follow the distribution of one of the major superficial veins Ref: Schwaz's principle of surgery 9th edition, chapter 17.