@article{oai:tsukuba.repo.nii.ac.jp:00054068,
 author = {松岡, 亮太 and MATSUOKA, Ryota and Watanabe, Motonobu and Ichimura, Yukako and Takagaki, Toshiro and Iitsuka, Yasushi},
 journal = {International Journal of Surgery Case Reports},
 month = {Jul},
 note = {Introduction
Rapidly enlarging mammary tumors, including invasive breast tumors, are clinically rare. Invasive micropapillary carcinoma (IMPC) of the breast is known to have aggressive behavior and poor clinical course compared to invasive ductal carcinoma.

Case presentation
An 87-year-old woman presented with a rapidly enlarging tumor of the right breast over the course of 3 weeks. Ultrasonography and computed tomography of the chest revealed a giant tumor located on the right chest wall, with heterogeneous parenchymal components and several cystic lesions. Emergency mastectomy was performed because of rapid tumor enlargement complicated by hemorrhage. Histopathological diagnosis confirmed a papillotubular invasive ductal carcinoma with an IMPC component. Tumor cells were negative for estrogen and progesterone receptors, and the human epidermal growth factor receptor 2 score was 2+.

Discussion
There has been only one report of breast carcinoma with rapid enlargement caused by spontaneous intratumoral hemorrhage to date. IMPC is associated with a high incidence of axillary lymph node metastases, frequent local recurrence, and a poor clinical outcome. In the present case, the specific breast cancer type can be considered as potential factors responsible for hemorrhage induction within the tumor that further enhanced rapid tumor growth.

Conclusion
IMPC is a rare, clinically aggressive variant of invasive ductal carcinoma. Owing to its aggressive clinical behaviors, surgeons should readily recognize the morphology of IMPC.},
 pages = {189--191},
 title = {Papillotubular carcinoma with an invasive micropapillary carcinoma component of the breast, characterized by a rapid increase in size due to intra-tumoral hemorrhage: A case report},
 volume = {38},
 year = {2017},
 yomi = {マツオカ, リョウタ}
}