Fat necrosis of the breast is a well-described benign entity that can result in unnecessary biopsy of breast lesions. The pathogenesis of fat necrosis is a non-suppurative inflammatory process of adipose tissue, which may be seen after trauma, surgery, biopsy, post-breast reconstruction, post-fat grafting, post-radiotherapy, infection, and duct ectasia, among other conditions. Clinically, these patients may be asymptomatic or may present with a palpable lump, skin tethering, induration, and occasionally axillary lymphadenopathy. Depending on the time at which diagnostic imaging is performed, fat necrosis can have highly variable appearances on different modalities as it evolves. This is directly related to whether inflammation or fibrosis is predominating within the lesion, and correlation with clinical history is paramount in evaluating these patients. This review aims to analyze benign and suspicious imaging features of fat necrosis confirmed by tissue sampling. Knowledge of both benign and malignant-appearing features of fat necrosis on conventional modalities such as mammography and ultrasound, as well as newer applications including digital breast tomosynthesis, PET/CT, and MRI, should help the radiologist minimize the number of unnecessary biopsies.

Pulmonary artery angiosarcoma is a rare malignant vascular tumor with an aggressive clinical course and a poor prognosis. Hemoptysis and shortness of breath have been reported as common clinical presentations. The exact clinicopathology is unknown. A tissue specimen obtained by percutaneous fine-needle aspiration cytology or open/thoracoscopic biopsy can confirm the diagnosis based on histopathological and immunohistochemical features. The differential diagnosis includes pulmonary thromboembolism, vascular malformations, and lung carcinoma. There is a paucity of literature describing this tumor, with only a few case reports available. There is also a lack of standardized guidelines for management, which further worsens the survival outcome. We report 3 cases of pulmonary artery angiosarcoma and review the recent literature.