Clinical History
51-year-old patient with lump and thickening of the skin in the right breast. Family history of breast cancer includes mother at age 70 and sister at age 54.
Imaging Findings
Mediolateral Oblique (MLO) and Cranio Caudal (CC) views of the right breast show a mass without calcifications in the axillary tail region measuring 6.5 x 5 x 2.5 cm. There is a BB marking the correlating palpable lesion. (Fig. 1A and B)
Ultrasound of the palpable lesion demonstrates a complex mass, with both solid and cystic components, multiple septations, and internal Doppler colour flow. (Fig. 2 A and B)
Dynamic Contrast Enhanced Breast MRI (DCE-MRI) shows a round mass with smooth margins and heterogeneous internal enhancement in the upper outer quadrant of the right breast. (Fig. 3-5)
Discussion
Breast sarcoma is a rare type of cancer arising from the mesenchymal tissue of the breast. Primary breast sarcoma is seen in less than 1% of all primary breast malignancies and less than 5% of all sarcomas.
The risks of developing breast sarcoma are unknown. Some authors have shown a significant correlation between external beam radiation of the breast or chest wall and sarcomas.
Breast sarcoma is most commonly diagnosed in patients who are in their fifth or sixth decade of life.
The most common clinical presentation is a unilateral, well-defined, mobile and painless breast lump which grows rapidly in a short period of time.
Metastases from breast sarcoma are typically haematogenous and involve the lung, bones and liver. Lymph node metastases are rare.
The mammographic appearance of breast sarcoma is non-specific, non-spiculated dense mass, usually without calcifications, just as seen in this case.
Sonographic evaluation demonstrates hyperechoic with no posterior shadowing. In our case the ultrasound shows a complex mass with internal Doppler colour flow.
MRI may be useful in further evaluating breast sarcoma and possible chest wall involvement. The typical appearance of malignant breast lesions by DCE-MRI includes kinetic assessment of rapid enhancement with “washout” characteristics and internal heterogeneous enhancement.
Prior to the initiation of treatment the optimal treatment of breast sarcoma involves the interactions of a multidisciplinary team, including breast imager, surgeon, oncologist, and radiation therapist. Patients with tumours less than 5 cm undergo complete resection with negative margins. Negative surgical margins are important for local recurrence and overall survival than the extent of surgical resection. Neoadjuvant chemotherapy should be considered in order to shrink the tumour and obtain negative surgical margins.
Radiation therapy should be used to improve local control in cases in which the tumour is larger than 5 cm and in cases with positive margins.
In this case, the core biopsy was difficult to interpret and it was not until the definite surgical excision that the pathologist was able to provide the definite diagnosis of breast sarcoma. The patient underwent partial mastectomy, axillary lymph node dissection and adjuvant chemotherapy and is now doing well.
Key Points:
Primary breast sarcoma is an extremely rare and heterogeneous disease.
MRI evaluation is important in assessing chest wall involvement
The appropriate treatment of breast sarcoma requires a multidisciplinary team approach.
Differential Diagnosis List
The final pathology diagnosis is undifferentiated pleomorphic sarcoma.
Invasive ductal carcinoma
Cystosarcoma phyllodes
Metaplastic carcinoma
Intracystic papillary carcinoma
Pleiomorphic sarcoma
Final Diagnosis
The final pathology diagnosis is undifferentiated pleomorphic sarcoma.
