Background
Spindle cell lesions of the breast present a unique diagnostic challenge for breast radiologists. These lesions represent a variety of both benign and malignant entities that have a wide range of presentations. Spindle cell neoplasms also have overlapping imaging and histopathologic features. Due to the potential for malignancy, these lesions often require excisional biopsy to ensure the correct diagnosis is made and subsequently guide the correct treatment plan.
Educational Goals / Teaching Points
The objective of this exhibit is to identify examples of spindle cell breast lesions, both benign and malignant, using a case-based approach. We will review multimodality imaging and histopathological features, as well as recommended treatment and management options for these various diagnoses.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
Spindle cell lesions of the breast are broadly characterized by their mesenchymal, or spindle cell, proliferation with or without an epithelial component. Commonly, these present as either a palpable abnormality or are identified incidentally. Examples of benign spindle cell lesions of the breast include, but are not limited to, pseudoangiomatous stromal hyperplasia (PASH), fibromatosis, myofibroblastoma, and benign phyllodes tumor. Malignant spindle cell lesions include metaplastic or spindle cell carcinoma, malignant phyllodes tumor, malignant melanoma, and multiple forms of sarcoma. Using a combination of imaging modalities including mammography, ultrasound, and/or MRI, radiologists can determine appropriate next steps in management. With tissue sampling and histopathological evaluation, an accurate diagnosis can be ascertained and help the clinician decide on follow up versus surgical intervention.
Conclusion
Spindle cell lesions of the breast comprise a broad spectrum of benign and malignant diagnoses. Deeper understanding of common presentations, imaging features, and histopathological associations can help narrow a vastly wide differential.
