Rare Case of Breast Sarcoma and Associated Imaging Findings

Author: Emily Behling
Program: Medicine
Mentor(s): Shannon Wilson, MD
Poster #: 90
Session/Time: A/2:40 p.m.

Abstract

Introduction:

Breast sarcomas are a rare form of cancer that make up fewer than 1% of all diagnosed breast cancers. These tumors are made up of malignant mesenchymal tissue and typically develop in women 55-59 years of age. A primary breast sarcomas presents as a rapidly growing mass of the breast, without nipple involvement. Breast sarcoma can be associated with genetic syndromes including familial adenomatous polyposis, neurofibromatosis type 1, and Li-Fraumeni syndrome. Breast sarcomas are difficult to distinguish based on clinical features and although cases may have imaging findings that are common, these are often nonspecific. Pathology is therefore used to obtain a definitive diagnosis. These tumors tend to be treated with mastectomy, adjuvant chemotherapy, and radiation. The 5 year survival rate for breast sarcoma has been documented as low as 14 percent. Here we report the case of a pathology-proven stage IIIa primary breast sarcoma in a 39 year-old female.

Case Information:

The patient is a 39 year old female with no prior history of cancer, no history of radiotherapy, and no history of smoking. She presented with a rapidly enlarging palpable left breast mass in the lateral upper quadrant after a year and a half of breastfeeding. Patient underwent mammography and breast ultrasound for further evaluation which demonstrated a large hypoechoic, heterogenous mass with internal cystic structures, prompting further evaluation with fine needle aspiration of the mass. The pathology report from the biopsy demonstrated findings of a high grade sarcoma. Further imaging was obtained with CT which revealed that the breast mass came in close proximity to the chest wall but did not show any invasion. Patient underwent treatment with a left total mastectomy with negative margins. The subsequent postoperative pathology report confirmed a high grade undifferentiated pleomorphic sarcoma. Adjuvant chemotherapy was initiated with no evidence of recurrence 7 months after diagnosis, the patient is also anticipated to undergo adjuvant radiation upon completion of chemotherapy. Genetic testing was obtained at the time of diagnosis and did not reveal any genetic predisposition.

Discussion:

Breast sarcomas tend to be difficult to diagnose as they cannot be definitively identified using standard approaches such as mammography and ultrasound. Our case supports this finding as a mammogram and ultrasound both identified the suspicious mass, but a subsequent tissue biopsy was used to make the definitive diagnosis. Diagnosis of breast sarcoma is essential due to its aggressive nature which necessitates surgery in most cases. In addition, preoperative diagnosis of breast sarcoma is important because it can change operative management. While lymph node dissection is common in epithelial breast malignancies, it is not indicated in breast sarcoma due to low rates of nodal spread. This case may also anecdotally suggest that it's important to consider breast sarcoma as a diagnosis for younger women. Our 39-year-old patient is somewhat younger than the 55-59 year-old patient population most commonly diagnosed with breast sarcoma.

Conclusion:

Breast sarcomas are rare tumors that should be considered as a broad differential diagnosis for a breast mass. The heterogeneous patient population and features of these tumors, as well as the lack of definitive imaging findings render breast sarcomas difficult to diagnose. Preoperative diagnosis is important and can be made with a tissue biopsy. Treatment for breast sarcomas involves surgery as well as adjuvant chemotherapy and radiation which requires close collaboration with the radiology, surgery, and pathology teams.