41 A Case Series of Sarcomas

Background

Breast sarcomas are malignancies of mesenchymal cell lineages. They are rare and generally more aggressive than breast adenocarcinomas. The primary form arises de novo, and the secondary form is often treatment-related. Management remains highly variable. Experiences from retrospective studies and case reports can help identify patterns.

Methods

Summary of the 5 Patients' Breast Sarcoma Histology, Size, Grade, Staging, and Margins

We discuss 5 cases: (1) 86F with a secondary angiosarcoma 6 years after lumpectomy/radiation to treat left breast mucinous carcinoma; (2) 44F with a 2-year history of an enlarging, biopsy-proven left breast angiosarcoma; (3) 39F with a 2-month history of an enlarging, biopsy-proven right breast angiosarcoma; (4) 60F with enlarging left breast mass on mammograms over 2 years with biopsies showing focal bone metaplasia; and (5) 59F with recurrent left breast phyllodes tumor.

Results

Patients 1 to 3 underwent mastectomy. With negative margins, patient 1 had a latissimus flap to cover the large wound. Three months later, she underwent excision of recurrent skin lesions and radiation. She declined palliative chemotherapy. Her cancer was upstaged from IIIB to IV after biopsy-confirmed liver metastasis at 1 year. Patient 2 completed gemcitabine/docetaxel and doxorubicin treatment but progressed from stage IIIA to IV with osseous and liver metastases at 1 year and died. Patient 3 was staged IIIA with medical and radiation oncology referrals. Patient 4 underwent an excisional biopsy, which returned spindle cell neoplasm with bone and cartilage differentiation. Despite margin clearance after re-excision and 2 cycles of gemcitabine/docetaxel to treat malignant phyllodes (initial diagnosis slightly favored over metaplastic carcinoma), she had a mastectomy for recurrence 6 months later. Immunohistochemistry showed keratin expression more characteristic of metaplastic carcinoma. The patient will initiate pembrolizumab. Patient 5 had lumpectomy. Her phyllodes tumor showed marked stromal atypia but was classified borderline given no overgrowth relative to epithelium and its liposarcoma differentiation, which has low malignant potential. A 1-cm margin was assured after re-excision. She will continue mammogram surveillance.

Conclusions

Large, high-grade histology such as angiosarcoma or spindle cell confer guarded prognosis. Their presence often warrants mastectomy +/- chemotherapy or radiation. Lumpectomy is considered for smaller tumors with favorable histology such as liposarcoma and benign/borderline phyllodes. Negative margin status is essential for disease control.