Percutaneous transthoracic needle biopsy (PTNB) is a minimally-invasive procedure that is an indispensable tool for evaluating pulmonary lesions. Though extremely rare, tumor seeding of the pleura and chest wall can occur as a complication. Given that the breast is located anterior to the thorax, needle tracking through the breast is inevitable when PTNB is performed using the anterior approach. We describe tumor seeding of metastatic pulmonary ameloblastoma in the pectoralis muscle layer of the breast along the needle track of PTNB in a 51-year-old female presenting with a palpable lump in the right breast.

The purpose of this study was to evaluate the usefulness of MR imaging and to describe the MR imaging findings of pregnancy-associated breast cancer. Materials and Methods: From 2006 to 2013, MR images of 23 patients with pregnancy-associated breast cancer were retrospectively evaluated. MR images were reviewed to evaluate lesion detection and imaging findings of pregnancy-associated breast cancer. MR images were analyzed by using the Breast Imaging Reporting and Data System and an additional MR-detected lesion with no mammographic or sonographic abnormality was determined. Results: MR imaging depicted breast cancer in all patients, even in marked background parenchymal enhancement. Pregnancy-associated breast cancer was seen as a mass in 20 patients and as non-mass enhancement with segmental distribution in 3 patients. The most common features of the masses were irregular shape (85%), non-circumscribed margin (85%), and heterogeneous enhancement (60%). An additional site of cancer was detected with MR imaging in 5 patients (21.7%) and the type of surgery was changed. Conclusion: Pregnancy-associated breast cancer was usually seen as an irregular mass with heterogeneous enhancement on MR images. Although these findings were not specific, MR imaging was useful in evaluating the disease extent of pregnancy-associated breast cancer. Index terms

유방 엽상종양은 전체 유방 종양의 1% 미만을 차지하는 드문 섬유상피종양이다. 엽상종양은 유관주위 버팀질 세포에서 기원하여 상피 성분과 버팀질 성분을 모두 포함하는 특징을 가지며, 조직학적으로 양성, 경계성, 악성으로 구분된다. 엽상종양의 상피 성분에서 암이 발생하는 것은 매우 드물기 때문에 이에 대한 영상의학적 소견은 명확히 정립된 바가 없다. 이에 저자들은 21세 젊은 여성에서 경계성 엽상종양 내에서 생긴 침윤성 유관암을 경험하였기에 자기공명영상을 포함한 영상의학적 소견과 조직병리학적 소견을 보고하고자 한다.